RS975U - SCREW ENDOOSEAL DENTAL IMPLANT - Google Patents

Abstract

A screw endooseal dental implant that is implanted into the bone of the upper or lower jaw and to which the prosthetic work is attached, which can be a metal-ceramic crown or bridge, characterized in that it consists of an intraoral part, i.e. implant carrier (1), transmucosal portion ie. the neck of the implant (2) and the intra-axial bandage ie. implant bodies (3).

Description

Technical field to which the invention relates:

The invention belongs to the field of oral implantology, i.e. dentistry in general. It refers to the shape of the dental implant that is implanted in the alveolar bone and that ensures the retention of the dental implant in the bone.

Technical problem:

The invention solves the problem of dental implant retention in the jaw in which the implant is implanted, that is, it ensures the survival of the implant in the implant site for the rest of its life.

State of the art:

The part of the implant that is embedded in the bone has had various forms, but none

the shape did not ensure the retention of the implants. Most often it was a ball shape at the end of the rod or a ribbed shape. These forms did not ensure the retention of implants and these implants were rejected by the bone tissue in which they were implanted.

Presentation of the essence of the invention:

The condition of the peri-implant, gingival and bone tissue is extremely important for the survival and prognosis of the implant. The function of the peri-implant tissue is manifold. First of all, it accepts and fixes the implant, prevents infection and distributes and amortizes forces in the act of chewing. The quality of the tissue around the neck of the implant is extremely important, that is, the relationship between the gingiva and the implant, which primarily prevents migration of the epithelial attachment. The connection between living tissues and the implant does not morphologically and functionally resemble the periodontium of a natural tooth. The periodontal tissue of natural teeth differs significantly from the peri-implant tissue. The attached epithelium and connective tissue fibers of the gingiva of the tooth ensure a healthy and strong connection between the tooth and the periodontium, which prevents the penetration of saliva and bacteria along the surface of the tooth root. The gingival sulcus is 1-2 mm deep, on the outer wall there are several layers of squamous epithelium (sulcus epithelium). At its bottom is the attachment epithelium, fixed to the tooth enamel or cement. Collagen fibers more apical than the attachment epithelium make an organic connection with the tooth root cement. The inflammatory process, regardless of the great resistance of the periodontium, destroys the attachment epithelium and other tissues in the applicative direction, forming a periodontal pocket, that is, leading to periodontopathy. The prognosis of endosseous dental implants is determined, among other things, by the quality of the connection between the implant and the gingiva in the part where it penetrates the oral mucosa.

An organic connection between the connective fibers and the neck of the implant (an analogous connection exists in the area of the neck of the tooth) cannot be established. There is only contact between the neck of the implant and the gingiva, the intensity of which depends on the turgor of the connective tissue fibers and the health of the gingiva.

If the gingiva becomes inflamed, edematous and red, it tends to twist and separate from the surface of the implant. In this way, a door is created for infection to enter the implant bed in the bone. Therefore, all measures should be taken to maintain close contact between it and the surface of the implant neck.

Of primary importance for the success of endosseous implants is the creation of a tight perimucosal bond on the surface of the implant neck. Otherwise, migration of the epithelium occurs apically, that is, complete encapsulation and rejection of the implant. A good connection between the implant and the bone is one of the most important prerequisites for the formation of functional supracrestal connective tissue, which surrounds the implant. In order to achieve the epithelial attachment, an operative technique should be applied to the soft tissue with as little trauma as possible, an implant should be placed in the area of the keratinized alveolar mucosa and, if this is not possible, a free mucosal autograft should be performed. Likewise, exceptional oral hygiene (chemical and mechanical plaque control) is necessary, as well as the use of implants whose supracrestal part has a smooth surface. The gingival epithelium and fur play a very significant role in the clinical retrieval of implants over a long period of time. However, numerous experimental and clinical studies indicate that a ring is formed around the neck of the implant, understood without growing into the metal or ceramic material, as a sufficient barrier that primarily depends on the quality of the superstructure and the health of the gingiva, while inflammation separates the gingiva from the implant, allowing infection to penetrate.

The installation of endosseous implants causes traumatic damage to the bone structure, regardless of how carefully the procedure is performed with proper operative technique and with the use of appropriate equipment. This procedure therefore causes a bone response that is controlled by wound healing factors, biological mechanisms and mineral metabolism. The healing processes of the bone wound around the implant are very complex and consist of two separate mechanisms, which take place at the same time and are very important for the success of biointegration of the implant. These are, on the one hand, the inflammatory reaction associated with foreign body reactions and, on the other hand, the reaction of osteogenesis and remodeling, the outcome of which is the most important for the final success of the implantation. The principles of bone remodeling are based on resorptive processes under the influence of osteoclasts, that is, on osteogenetic reactions under the influence of osteoblasts. Bone tissue also has a high regenerative capacity thanks to the function of periosteum and endoosteum.

From the aspect of endosseous implantation, the quantity and quality of bone tissue are very important. The quantity of bone tissue is a category defined by the macromorphological parameters of thickness, height, width and shape of the bone body of the jaws in the area of implantation. It is determined by age, that is, the speed, degree and direction of resorptive processes in the jaws. Bone quality represents a fine, micromorphological category defined by the density and arrangement of cancellous bone trabeculae.

The bone response to the presence of an implant includes several physiological phases:

• formation of endoseal and periosteal microcallus,

• maturation (thickening) and remodeling of the callus,

• remodeling of the space between the surface of the implant and the adjacent bone, i

• maturation, i.e. mineralization of new bone in seconds.

Osseointegration implies direct bone apposition to the implant body, leading to fusion and ankylosis. It is defined as contact between normal, remodeled bone and the implant without interposition of connective non-osseous tissue. The degree of mobility or immobility of the implant before and after the prosthetic procedure is the best parameter of osseointegration for the clinician. Clinical and radiographic findings, as well as a ringing percussion sound, serve as additional indicators. If no osseointegration has occurred, the implant is mobile and gives a dull sound when percussed.

All researchers and practitioners believe that overheating of the bone during the formation of the bed, high pressure during installation and premature loading of the implant, most often cause migration of the epithelium apically, which compromises osseointegration. The basic prerequisites for achieving osseointegration are: that the implant is placed deep enough, that it is conical or cylindrical in shape, that it is completely covered by the flap and that it remains in a state of rest for at least 4-6 months. In this way, the implant is not traumatized, and the ossification process proceeds smoothly. The formation of surface oxide (TiCh) on titanium or titanium alloys is probably one of the reasons for the extraordinary biocompatibility of this metal.

An essential condition for osseointegration is that the endoseal part of the implant be closed in the alveolar bone and unloaded in the so-called afunctional state three to six months after installation, which implies a two-phase installation procedure.

The most important factors for osseointegration are:

• application of titanium implants of high purity,

• creation of an oxide layer that later calcifies on the surface of the implant,

• even distribution of occlusive stress,

• internal cooling during installation (temperature up to 40 degrees and number of revolutions up to 2000)

• two-phase installation of implants,

• aseptic work, and

• formation of tissue around the neck of the implant.

On the other hand, the criteria for successful osseointegration of implants are:

• complete rest of the implant in the bone,

• absence of bone loss,

• there is no lighting on the Rd recording,

• no complications of pain, infection or nerve damage, i

• the percentage of success in the next ten years must be over 90%.

Metals, especially titanium, form a surface oxide layer that is similar to the surface herniation of hydroxyapatite, and this is probably why titanium is so successful as an implant material. The presence of titanium dioxide gives titanium the ability to induce the deposition of calcium phosphate crystals on the surface of the implant, which does not occur without the presence of oxide. Superficial titanium dioxide herniation can be further chemically manipulated, and depending on the manipulation, bone reaction can be not only reduced but also enhanced. Fluoride has, documented, promotional activities. By incorporating fluoride ions into the titanium oxide layer, it is possible to significantly increase the survival of the implant, even compared to implants with a rough surface.

Fibroosseous healing is the creation of healthy collagen tissue between the implant and the bone. The metal implant is encapsulated by granulation tissue, which cicatrizes, forming a fibrous capsule, a connective-tissue sleeve located between the implant and the bone. In fact, after the implantation of the implant, a healing process occurs: an inflammatory reaction, first by the formation of coagulum, granulation and then fibrous tissue, which is formed by the maturation of the granulation tissue, leading to encapsulation, i.e. failure of implantation. In the literature, it is stated that the peri-implant tissue is the "equivalent of the periodontium of the tooth", that it is a false or "pseudoperiodontal ligament", that it has "osteogenetic potential", all in order to show that there is a raisom d'etre for some implant systems. For these reasons, the term biointegration is found in the literature, which means that every implant can be osseointegrated. From this, the concept of osseovariation arose, which implies that there is osseous and fibrous tissue around each implant. However, these implants are doomed to early inevitable failure. Non-mineralized tissue, not bone, forms around them.

The basic prerequisite for the survival of implants is successful osseointegration, not its encapsulation. Today, everyone involved in implantology is of the undivided opinion that implants that heal by osseointegration are the right choice, because they have a significantly higher and longer degree of success. Today, with a special treatment of the implant surface, and depending on the quality of the bone, the resting time of the implant is reduced to six to eight weeks after installation. There are also systems (Mono Type) that are installed and loaded on the same day. Therefore, it is a general aspiration of researchers and doctors to achieve early loading and ensure faster healing. The doctrine of two-phase implant installation is indisputable, but the question - for how long?

Before each implantation, one should take an anamnesis, determine the general state of health, take laboratory analyzes of blood and urine, take radiographs, clean the mouth and teeth, make study models and photos, ensure the written consent of the patients and consider the preconditions for implantation. For the success of the implantation, a good selection of patients is of particular importance, who will cooperate flawlessly with the doctor from the beginning, from the routine preoperative preparation, to the creation of the superstructure and later. In the selection of patients, the doctor should be restrictive, first of all taking into account the indications and motivation of the patient. Implantological diagnosis is based on the medical and dental anamnesis and a detailed clinical examination of the patient. It is extremely important to take a general anamnesis and perform an objective examination in order to prove or rule out any disease when the implant should not be installed. Assessment of the general state of health can be determined by a more detailed anamnesis, which should be entered in a separate record or questionnaire. Anything suspicious in the anamnesis requires additional examinations, which definitively prove or exclude a general illness. Individuals and teams dealing with implantology, in addition to standard health records, have established implantology records and protocols that they strictly adhere to. The protocol contains all relevant parameters starting from general data to multi-year monitoring and control of patients in the spirit of the documents adopted at the conferences in Harvard, Toronto and Bethesda.

Implant placement is a multidisciplinary problem involving general practitioners, specialists, dentists, oral and maxillofacial surgeons, prosthetists and dental technicians. The findings of all these expert profiles are contained in the protocol, which ensures complete and satisfactory patient care. Dental anamnesis and examination of the oral cavity must be deleted in every candidate for implantation. The anamnesis indicates motivation, which is the key to success, the cause of tooth loss, the level of oral hygiene and the patient's desire for constant cooperation. Finally, the general and local state of health and the characteristics of the bone tissue in which the implant is implanted determine the choice of patients. For the successful application of dental implants, the most important is the following:

• selection of patients, pre-implantation preparation, x-ray diagnostics,

• choice of implant (length, diameter),

• correct surgical technique, i

• production of supiastructure, i.e. prosthetic compensation.

There are no restrictions for the installation of implants in the elderly, provided that there are no general and local contraindications, which are taken into account in all ages.

The clinical experience of many doctors has shown that implant placement in elderly people is just as successful as in young patients. On the other hand, many are against implant placement in children in the phase of growth and development.

Before installing the implant, the patient should give written consent for the operation. His signature confirms that he is fully aware of the procedure and the possibility of implantation failure, on the one hand, and the protection of the doctor against possible patient complaints, on the other hand. He is introduced to the possible possibility of failure and is presented with the importance of cooperation with the doctor. Also, he gives his consent to come for control regularly, according to the protocol. This is very important for the long-term survival of the implant.

The pre-operative procedure includes complete restoration of the mouth, removal of plaque, calculus, soft deposits, tooth extraction, pre-implantation surgical interventions as well as treatment and filling of the remaining teeth. Postoperatively, cold compresses, impeccable hygiene, rinsing the mouth with chlorhexidine (Hibidex) and, if necessary, analgesics and antibiotics are recommended to the patient. After installing the implant, it is necessary to constantly monitor the patient. Regular and constant control of the patient, i.e. the installed implants, is performed several times during the year. Control involves assessment of oral hygiene, i.e. plaque, gingival condition, pocket depth, implant mobility, occlusion and articulation, and radiography. If necessary, study models and photographs should be made. The production of study models is required to accurately determine the interjaw relationships, the arrangement of the remaining teeth and the assessment of the residual alveolar ridge. A surgical template made of acrylic is made on the study models, on which the positioning of the implant installation site is precisely determined. It is equally important to make study models in both pronounced edentulous and completely edentulous patients. In the routine preoperative procedure, when selecting patients for implantation, biochemical blood analyses, blood count and sedimentation should be performed. In laboratory analyses, attention should be paid to blood sugar level, alkaline phosphatase, fibrinogen, creatinine, liver function tests, K, Ca, total number and distribution of leukocytes, erythrocytes, blood platelets, etc. Mandatory laboratory tests are determination of hemoglobin, sedimentation, glycemia and leukocyte count. If there is a suspicion of metabolic disorders of calcium, its values should always be tested in the laboratory. Findings that deviate from the reference values should be considered. Bone quality assessment is very important for implantation. This assessment is especially important in people in their 60s and older due to the more frequent osteoporosis that occurs due to bone demineralization. On the orthopantomographic image, such cases look like D4 type bone density - a thin cortical lamella with poorly mineralized spongiosa, which points to caution and the need to do a CT scan and consult an expert doctor who deals with these problems (orthopedic, rheumatologist, endocrinologist).

For implantation, starting from the installation of trarisdental to two-phase endosseous implants, X-rays are especially important and sometimes decisive for setting the indication. In deciding on the choice and installation of implants, radiography is of great use, which shows the area where the implant beds and the surrounding anatomical structures will be formed.

X-rays are also used immediately after installation, to show that the implant is completely in the bone and that no anatomical structures have been damaged, as well as during regular controls when monitoring the healing process. They are also used for the diagnosis of intraoperative and postoperative complications.

Small dental films, orthopantomography, digital orthopan, lateral profile images of the upper jaw, tomographic imaging or computerized tomography are most often used.

The height of the alveolar ridge, the quality and structure of the bone, i.e. its density and structure, are evaluated on the retroalveolar images. On orthopantomography, the height of the alveolar ridge is measured, but a magnification of 15-25% is obtained, depending on the region being imaged. The degree of enlargement is greatest in the area of premolars, about 20-25%, then in the area of incisors 10% and in the area of molars 10-15%. This type of imaging is necessary before implantation, regardless of the fact that it provides a certain degree of magnification and a cross-sectional image of the object. In this image, there are structures in front of or behind the axis of the section that are otherwise not clear enough or not visible at all.

Computerized technology makes it possible to obtain an X-ray image using the digitization method based on the conversion of an analog to a digital image. In this way, it is possible to computerize all radiological techniques, starting from small intraoral X-rays to performing tomographic imaging methods. The computer part of the device with a special electronic receiver converts the received signals into a digital image. With the orthopan tomogram obtained by the digital method, measurements can be made with deviations that are less than 2%.

Lateral or profile images are particularly useful for transdental implantation because they show the angulation of the roots in the vestibulooral direction and the height of the subapical part of the bone. Profile side view of the frontal part of the lower jaw shows the direction and width of the bone, which significantly affects the direction of installation of endosseous implants. Tele-X-ray and tomographic imaging are used for a more accurate evaluation of the bone height of the maxillary space or the height and width of the alveolar ridge in the area of the molars when the distance between the mandibular canal and the sinus cavity needs to be precisely determined. Computed tomography is used for planning the installation of implants. CT provides a three-dimensional image of the patient's mouth, the quality and shape of the bone and the exact location of anatomical structures. With this type of imaging, the shape and direction of the alveolar ridge, the thickness of the alveolar ridge, the measured distance from the sinus, nose and mandibular canal are recorded and the buccolingual position of the mandibular canal is determined. CT is particularly recommended for precise determination of the width and height of the alveolar ridge. Surveys can be made with markers whose size is known in order to accurately determine topographic relationships. By placing an indicator over the image, the implant can be precisely selected, taking care that the magnification of the drawing corresponds to the magnification on the orthopantomographic image. Measuring the bone on transparent templates or R6 indicators, which are compared with the preorerative orthopantomographic image, with calculation and deviations of 20-25%, implant selection is made in each individual case. In doing so, one should always assume that the implant is larger than the smaller one, taking care not to injure the adjacent anatomical structures. A larger implant ensures better success, as it has a larger healing surface. Based on the analysis, knowing the height and width of the alveolar ridge, an implant of the appropriate length and diameter can be selected. All of this indicates that the precise interpretation of the X-ray image can be used to determine the size (proximity) of the sinuses and nasal cavity, the position of the mandibular canal and chin opening, and especially the height and width of the alveolar ridge of the lower and upper jaw. Assessment of the quality of the bone structure, which is extremely important for implantation, is also performed by analyzing preoperative X-rays.

In general, the indications for implantation are toothlessness of the lower and upper jaw, partially edentulous saddle and multiple or single tooth loss. Indications for implantation depend on the patient's choice, i.e. his willingness to cooperate from the first examination to regular superstructure controls. Indications for implantation are fractures of the upper or lower jaw, i.e. immobilization of bone fragments, loss of bone tissue during trauma or after tumor surgery, loss of teeth during trauma, etc. Endoseal implants are most often installed when one tooth is missing from the upper or lower front, premolar or molar (class I), one-sided edentulous saddle, bilateral edentulous saddle (class II), when several teeth in a row are missing (class III) and when it comes to edentulous lower or upper jaw (class IV).

Contraindications for the installation of endoseal implants can be general and local. General contraindications for the use of implants are numerous and include the presence of various systemic diseases, such as: bone diseases (Paget's muscle, Recklinghausen's muscle), pronounced osteoporosis, rheumatic diseases, coagulopathies, severe nervous diseases, metabolic disorders, endocrine disorders, patients undergoing or immediately after radiotherapy. Emotionally unstable patients, as well as alcoholics and drug addicts, and poorly motivated patients should also not be included as candidates for implant placement. Local contraindications are also numerous and include: poor hygiene habits, the presence of parafunctions (bruxism), unfavorable arrangement of the remaining teeth, unfavorable interjaw relationships, inadequate space, marked atrophy of the alveolar ridges (possible subperiosteal implant), marked pneumatization of the naxillae (sinus proceidens, possible Sinus-lift surgery), high position of the chin opening on the ridge (and this can be solved by implantation), dermatoses and recurrent infections of the soft tissues of the mouth, pathological changes in the bones jaw, the presence of severe abnormalities of the teeth and jaws, macroglossia, etc.

Significant prerequisites for implantation are the condition of the bone and soft tissue of the residual alveolar ridges (RAG). The quality of the bone, i.e. its porosity and density, height, width and length, should be evaluated in particular. The available amount of bone is an important prerequisite for implant placement. The shape and size of the ridge, the arrangement of spongiosa and compacta, as well as the degree of atrophy, influence the decision to place an implant. Resorption of RAG is usually unequal, even when it comes to the same patient. The condition of the alveolar ridge before implantation should be carefully assessed and possibly its augmentation (enlargement). It goes without saying that the ridge should be carefully palpated for undermined parts, bony defects and exostoses. All that, as said, can be detected by computerized tomography. In order to prevent the atrophy of the alveolar ridge and the formation of the ridge like a knife edge, today, immediately after tooth extraction, an implant based on hydroxylapatite or tricalcium phosphate or a bone and membrane substitute is inserted into the alveolus to preserve the height of the ridge and its contour. The process of resorption and remodeling ends in one to two years after tooth extraction. Given that the cortical lamella is thinner on the outside than on the palatal side, ridge resorption is more intense buccally.

For the installation of endosseous implants, the height and width of the available bone of the residual alveolar ridge is important. Bone height is the distance of anatomical structures (nose, sinus, mandibular canal) from the top of the alveolar ridge. A crest of sufficient height ensures the installation of longer implants without fear of injury to the aforementioned structures. The height of the ridge can be determined radiologically, CT, marketing and indicators. Ridge width is the distance between the cortex of the oral and vestibular sides of the alveolar ridge. The width of the ridge is important for choosing the type of implant to be installed. Thus, cylindrical and screw implants can be installed in wide and medium-width ridges, while leaf-shaped ones can be installed in both cases, but also in narrow alveolar ridges. A thin alveolar ridge with unevenness can be leveled with Lier's forceps or special Birches and drills. In this way, a ridge width of three to six mm can be provided (only if the height of the ridge allows) for the acceptance of larger diameter implants. In fact, a satisfactory width of the alveolar ridge should provide enough bone to surround the implant from the outside and inside, at least 0.5-1 mm. The thickness of the oral and vestibular cortical lamella determines the long-term survival of the implant. To read the ridge width, special instruments called osteometers are used, on which there is a meter graduated in millimetres. Measuring the ridge is necessary, first of all, because due to the presence of a thicker layer of mucosa, it can be mistakenly concluded that the ridge is of satisfactory thickness. Therefore, it happens that after opening, exploitation, it is found that the ridge is resorbed and that its buccolingual and buccopalatal width is so small that the implant cannot be inserted, because the thickness of the soft tissue on the ridge completely masks the degree of bone resorption. Under local anesthesia, two measurements are taken: at the very top and every five to seven millimeters below the top of the ridge. The width of the ridge can be measured, although not precisely enough, with a sharp probe with a rubber collar on it. The thickness of the mucous membrane is measured under anesthesia. A round rubber bumper is placed on a sterile graduated needle and goes to the bone. By measuring the length of the probe under the bumper, the thickness of the mucous membrane from the external and oral side can be determined. Before the operation or during the operation, on the basis of the impression, situational templates are made of autopolymerizing acrylate and mark the places where the implants will be installed. First of all, it helps to position the implants and choose the right angulation in relation to the remaining teeth and the residual ridge. By aligning the condition in the mouth and on the model in the slate template, perforations are made that show where the implant bed should be made. In the second phase (reoperation), the places where the implants are inserted are simply found using templates.

The structure of the jaw bone consists of compact lamellar bone and spongy laminar bone. Compact bone is solid and compact bone mass, while spongy bone is softer and looser, with many bone canals and beds in which the bone marrow is located. Compact bone can be thin or thick, and spongiosa is either hollow or dense. Therefore, it is very important to assess the quality of the bone before each implantation. The best bone is when there is mild resorption and dense bone, while strong resorption with thin, compact and hollow spongiosa is the most unsuitable for implantation. The arrangement and mutual relationship of compact and spongiosa depends primarily on the age of the patient, on the jaws (lower, upper) and region (intercanines, molars, tuber, etc.).

The finer structure of the bone, i.e. its structure or density, is especially important for endosal implantation. A denser bone structure, more calcified and mineralized bone, accepts the implant better than loose, unmineralized bone with a lot of hematopoietic fatty tissue.

The clinical success of implants in the upper jaw is significantly lower compared to implants in the intercanine area (symphysis).

The distance from the top of the ridge to the nasal cavity is five to 20 mm, which can be pre-determined by special diagnostic methods before the decision on implantation.

The sinus cavity, due to bone atrophy, can be at a distance of one to 15 mm. According to the findings of this research, the largest number of cases were in the group where the distance between the floor of the sinus and the top of the alveolar ridge over the entire length was over eight millimeters (58.9%), while the rarest cases were two to five millimeters (15.6%). The shortest sinus distance is in the area of the first molar and its side walls. Resorption of the alveolar ridge after tooth extraction and lowering of the sinus more or less impoverishes the alveolar ridge, making the conditions for implant placement more difficult.

The direction of the mandibular canal does not change during bone resorption, while its position towards the top of the ridge depends on the degree of atrophy. This distance ranges from three to 15 mm. In the sagittal direction, the canal is four mm away from the buccal cortex and between two and three mm from the lingual. The canal is usually three millimeters in diameter and narrows from the chin opening, until it is completely lost in the middle of the jaw as an incisive canal. These relationships influence the choice of implant, primarily its shape and size. For implant selection, it is very important to know that the canal is placed more buccally (laterally) and that the distance of the roots from the contents of the canal is increasing as you move forward (more medially).

Prevention of injury to the chin opening is ensured by installing the implant at a distance of four to six mm, depending on the degree of resorption.

A good choice of implants and radiological assessment prevent injury to the sinus and nasal cavity, as well as the mandibular canal and chin opening.

Assessment of the condition and relationship of soft and bone tissue before implantation is extremely important. Soft tissue correction before or during implantation ensures longer-term survival of the implant.

This primarily refers to persistent labial frenulums in the upper and lower jaw (low or high attachment), blister attachments, mucosal fibromatosis, prosthetic hyperplasia of the mucous membrane, the relationship between mobile and immobile mucosa (shallow vestibular sulcus) and the relationship between the attached gingiva and alveolar mucosa.

Labial frenulums consist of fibrous tissue covered by mucous membrane. They occur more often in the upper jaw than in the lower jaw. Labial frenulums can insert on the outside or even on top of the alveolar ridge, which is very unfavorable for implantation. That is why phrenoplasty should be done. An incision is made on both sides of the frenulum through the mucous membrane and then it is separated from the alveolar ridge by dissection and direct sutures are placed. If direct sutures can be performed, the wound surface is covered with a surgical bandage, or a free mucosal graft is performed.

Plastic surgery of congenital and acquired blisters is done in a similar way as phrenoplasty. In both cases, it is possible to apply a free mucosal graft or some other surgical method.

Fibromatosis most often occurs on the tuber of the maxilla and in the trigone of the retromolar. It can appear as a moving ridge on any part of the alveolar process. In order to create conditions for implantation, these anomalies are eliminated by elliptical excisions of excess tissue.

Prosthetic hyperplasia occurs as a result of trauma due to poorly made prostheses. Hyperplasia of the mucous membrane has a characteristic clinical picture, there are one or more folds on the mucous membrane between which there are cuts on the mucous membrane that is completely inflamed, partially necrotic and painful. The prosthesis should be removed from the patient for a month when marked regression is visible. In addition, it is necessary to operate on mucosal hyperplasia before implantation. Elliptical excisions of the mucous membrane, free mucosal or skin grafts, or some other method that provides immobile mucosa at the planned implantation site are most often performed.

Atrophy of the alveolar ridge, even or uneven, occurs after tooth extraction or wearing dentures as a result of inactivity of the jaws or ridges. Atrophy of the ridge is also manifested as an unfavorable relationship between immobile and mobile mucosa, because the immobile mucosa decreases and the mobile one increases, sometimes massing at the very top of the alveolar ridge. From the point of view of implantation, the degree and form of atrophy not only of the bony part but also of the soft, mobile tissue, which progresses more slowly, are significant.

From this arises the need to perform vestibuloplasty before implantation, i.e. to change the ratio of mobile to immobile mucosa. It is understood that a good assessment of the residual alveolar ridge is necessary before deepening the fornix. It is possible to deepen the vestibule on a smaller, limited part of the upper and lower jaw, or on the entire jaw. In the upper jaw, the border moves up - cranially, and in the lower jaw - down - caudal.

Many operative methods of deepening the fornix have been described - free epithelization of the wounded surface, trichization of the wounded surface, submucosal vestibuloplasty, combined vestibuloplasty and lingual sulcoplasty according to Rerhman and Obweger and a number of others.

Today, from the point of view of success and simplicity, trained, experienced doctors apply Edlan-Meicher vestibuloplasty surgery or free mucosal autograft for these purposes, most often on an outpatient basis.

Edlan-Meicher's vestibuloplasty surgery is most often performed in the intercanine space of the lower jaw, when total toothlessness is solved with the installation of implants. An incision is made from the top of the alveolar ridge and its mucous membrane towards the mucous membrane of the lips in a length of one centimeter, and then they join each other along the mucous membrane of the lips. Blunt dissection separates the flap and transfers it over the top of the ridge towards the lingual. The periosteum is cut in the middle of the alveolar ridge and transferred together with the muscles towards the mucous membrane of the lips and ears. The alveolar ridge is covered with a mucosal flap and fixed with sutures. It can also be fixed with a surgical bandage. The postoperative treatment is prolonged and quite painful, and the effects are visible after a month. Fornix deepening surgery can be done in the same act as implantation. Edlan-Meicher's vestibuloplasty often does not give satisfactory results because the mucous membrane that is placed over the bone heals scarred and relapses occur. On the other hand, the mucous membrane on the bone is not keratinized and is often injured.

Rerhman applied his method to the closure of an oroantral fistula. The buccal vestibular flap is raised and cuts the periosteum at the base to cover the entire extraction wound. Rehrmann's plastic is also applied during immediate implantation. The disadvantages of this plastic are that it endangers the depth of the labial and buccal fornix and does not provide a keratinized attachment gingiva, so it moves towards the top of the alveolar ridge, which is aesthetically unsatisfactory.

Some authors, in order to improve the aesthetic result, recommend free mucosal graft, coronary displaced flap, apically displaced flap, pedicle flap, application of resorbable or non-resorbable membranes and free connective tissue grafts, in addition to the mentioned Rerhman plastic.

With a free mucosal autotransplantation, the fornix can be deepened, the attached gingiva expanded, and the defect after frenectomy or blister plastic can be covered. For the free mucosal autograft, the palatal mucosa is taken due to keratinization, and more often the buccal mucosa.

Keratinized alveolar mucosa is much more suitable for implantation than nonkeratized alveolar mucosa. There are also clinical reasons for recommending the placement of implants in the keratotic mucosa. Non-keratized mucosa with alveoli is easily injured during tooth brushing, which is why the patient may neglect oral hygiene.

In the first act, a bed or "receiving region" is provided for placement of the mucosal graft. The bed is provided by an incision of the mucous membrane of the alveolar ridge in the fornix at the border of the mobile mucosa and the rest of the attached gingiva. After separating the mucous membrane by blunt dissection, the submucous tissue and muscles up to the periosteum are removed.

In the second act, a free mucosal graft is taken from the "donor" site on the palate, from the lateral side, from the area of the premolar and first molar. Its size depends on its purpose. Small salivary glands are removed from the inside of the graft. The mucous graft is placed on the prepared bed, fixed with rare sutures and covered with surgical packing.

A surgical bandage should also be placed on a fresh, wounded surface on the palate.

Satisfactory deepening of the fornix is achieved with this method.

Attached gingiva is the part of the gums from the marginal part to the mobile mucosa that is firmly attached to the periosteum, bone and tooth.

The width of the attached gingiva is of particular importance for implant placement. It can be completely absent or very narrow.

Mucogingival surgery aims to create an immobile mucosa around the neck of the implant.

The mobile mucosa often reaches the crestal part of the alveolar ridge, which endangers the survival of the implant due to muscle pull and pulling of the mucosa around the neck of the implant. Therefore, implantation should not be done without prior surgical expansion of the attached gingiva, which is most often successfully performed with a free mucosal autotransplant, mucoperiosteal and mucosal flap.

Alveolar ridge atrophy is a particular problem for implantation. Based on clinical and radiographic examination, atrophy is divided into four groups: in the first group there are patients with a ridge of sufficient height, but small width, in the second group, patients with a ridge small in both height and width; in the third, patients with complete atrophy of the alveolar cups reaching the basilar part of the bone and, in the fourth group, patients with resorption of the basilar part of the bone, a very gracile and thin lower jaw (possible fracture) and a flat, almost flat upper jaw.

In order to improve the state of atrophy, free bone and cartilage autograft and various alloplastic materials can be applied. These materials are applied in the form of granules or as a solid form, in pieces, which are adapted to the atrophic bone of the lower and upper jaw (ridge augmentation).

The application of bone and membrane substitutes has opened a new chapter in implantology. For these purposes, numerous alloplastic materials or natural bone materials are used to replace the bone of the lower and upper jaw.

Bone substitutes are of human, animal or synthetic origin. In addition to filling defects in the bone, they promote better healing because they act osteogenetically, osteoinductively and osteoconductively.

These materials are very similar to the mineral part of human bone and promote mineralization and new bone formation. They are considered biocompatible materials. They are microporous, non-toxic, do not cause allergies, do not behave like a foreign body, do not act carcinogenic, and often have a canalicular and intercanalicular system whose pore diameter is equal on all surfaces (sections). Due to such properties, the soft and bony tissues of the jaw tolerate them well, which offers great possibilities for their application for implantation. They are applied in the form of granules, and some of them in both solid and granular form.

For implantation, non-resorbable bone substitutes are most often Bio-oss, Interpore, Algipor, HTR and others. They can be applied in combination with bone autografts taken from the chin, buccal part of the mandible, tuber of the maxilla or by mixing with bone shavings that can be collected during the act of implantation. Bio-oss is most often applied as cortical or spongy granules or a spongy solid block of size 1x1x2 cm. Bio-oss is a material of bovine origin free of organic materials. It is prepared for use either with saline solution or with the patient's blood.

The indications for their use are as follows: increasing the width and height of the alveolar ridge, filling bony defects and the lower parts of the ridge, preparing the alveolus for the installation of implants, flow of fenestration and dehiscence around the implant, for immediate implantation, peri-implant treatment, after explantation, for raising the floor of the sinus (Sinus lift), "sandwich" osteotomy, etc.

The patient had two vertical incisions made on both sides between the canine and the first premolar. A subperiosteal tunnel was formed with the appropriate instrument and then granulated hydroxylapatite was injected through a vertical incision.

Ridge augmentation for implantation (increasing the height and width of the ridge) is done in a similar way. It is understood that the principles of guided tissue regeneration (GBR) apply in these cases. Aqueous bone regeneration (Bio-oss and Bio-guide membrane) is used for crest augmentation in order to later insert implants. Due to the property (structure) of Bio-ossa, recanalization and the formation of new blood vessels quickly occur, and after six months, the formation of new bone.

Bone substitutes also provide satisfactory results in the prevention of alveolar ridge atrophy. This is achieved by filling the alveolus after tooth extraction with bone substitutes, which significantly reduces resorption and achieves a good ridge shape for receiving implants.

Nyman et al. (1982) were the first to present the concept of membrane application based on the principles of aqueous tissue regeneration.

Whenever implantation is done, it is necessary to have a membrane so that, in case of need, aqueous bone regeneration, free bone grafts or alloplastic materials or a combination of both methods can be applied in larger defects.

Indications for the use of the membrane are as follows: guiding tissue regeneration in case of dehiscence and fenestration; filling the space between the alveolus and the implant body during early and delayed immediate implantation and increasing the alveolar crest; increase (augmentation) of the height and width of the ridge as a preparation for the later installation of the implant; raising the floor of the sinuses and filling smaller mined parts of the ridge.

The membrane is widely used in oral surgery and periodontology.

Today, resorbable or non-resorbable membranes are used with bone substitutes.

Resorbable membranes such as Bio-Guide, Goreresolut membranes are used more often than non-resorbable Gore-Tex, PTFE or titanium and Vvcryl membranes. Non-resorbable membranes show an effect in four to six weeks. They have to be removed by subsequent surgery (two-phase). Resorbable membranes have the advantage because they are single-phase and do not require reoperation. The exposed resorptive membrane can remain, and the non-resorptive membrane must be removed. They are of very low antigenic potential.

Resorptive and non-resorptive membranes are a mechanical barrier whose goal is to prevent the migration of the epithelium and connective tissue of the gingiva to the area of the surgical wound. This enables the creation of new bone tissue. It is precisely this fact that recommended them for implantation because it is based on the principles of specific aqueous tissue regeneration, the so-called. GTR technique (guided tissue regeneration).

By placing it over the defect, the membrane prevents the proliferation of epithelial cells into the defect and allows the formation of new bone.

Application of the membrane promotes bone regeneration and a high degree of osseointegration of the implant.

The tissues tolerate them extremely well, of course, provided that there is no infection at the application site. The residual tissue, where the membrane is placed, must be completely healthy. The membrane is placed to completely cover the defect in the bone, so that the rough part of the membrane is placed inward, on the autogenous bone graft or alloplastic material, and the flat, smooth part is placed towards the mucoperiosteal flap.

It is preferable to fix the membrane, especially if it is a larger defect. Fixation is done with titanium or resorbable pins. Resorbable pins are resorbed for up to twelve months, which affects the intensity of more complete bone regeneration. They are placed by perforating the cortical part of the bone in the immediate vicinity of the bone defect with a special drill.

Then, with a special instrument, a resorbable pin is placed in the perforation on the bone, after placing the membrane.

Periosteal autograft can also be used for these purposes.

The planning of the incision depends on the ratio of movable and immovable mucosa on the alveolar ridge, the type and number of implants to be inserted.

An incision is made to form a mucoperiosteal flap or flap, in order to reveal the bony ridge where the implants are placed. The base of the mucoperiosteal flap should be wider than the free edge and the larger flap should always be assumed to be smaller.

The incision should ensure good mobility of the mucoperiosteal flap, while it is necessary to avoid injury to blood vessels and nerves. The flap, completely and without tension, provides coverage of the implant.

Most two-phase implants are completely covered by a mucoperiosteal flap, which is adapted to the type of incision. On the other hand, there are two-phase systems (ITI, two-phase Linkov) where the incision is made in the middle of the ridge, without covering it with a mucoperiosteal flap.

For the installation of one-phase implants, the incision is made in the middle of the alveolar ridge.

The incision also depends on whether one or more implants are being inserted and whether they are being inserted in the presence of marked or partial toothlessness, or complete toothlessness of the lower and upper jaw.

This requires the use of several types of incisions, depending on the case. This is how they are most often done: incisions in the middle of the ridge, with or without relaxation in fomix; incision on the vestibular side; semicircular incision on the outside on the ridge with the possibility of relaxation palatally or lingually; semicircular vestibular with ridge extension (identification of mentalis nerve); incision from the palatal side of the alveolar ridge and buccal extension; incision for immediate implantation when it is necessary to mobilize the flap, as well as a number of others.

The incision can be planned so that the flap is mobilized, a perforation is made in it and it is pulled over the head of the implant (for single-phase). In this, as in all other cases, it must be ensured that the head of the implant is placed in an immovable mucous membrane. However, the depth of the vestibule is not compromised by the incision.

The flap is planned so that it must completely cover the bone. When the inserted implant is too close to the adjacent implant or tooth, the first suture should be placed mesially. In order for the flap to cover the bone and on the distal side of the implant, two relaxation incisions should be made on the gums on the oral and outer sides and the wound should be sutured. The distal part of the flap is easily rotated and sutured with extension sutures.

It has already been said that the success of implantation depends on the patient's choice, regular check-ups, maintenance of oral hygiene, ridge height and width, bone structure and soft tissue condition. In addition, a good indication and surgical technique, shape, design of the implant, its microstructure, type of material, provision of healing at rest and supraslTucture decisively influence the success of implantation when the strictest criteria are applied.

In the text that follows, a general overview of implants and the principles of creating a superstructure on implants will be given.

Implantation can be done immediately, delayed or late.

Immediate implantation is the installation of an implant in an empty alveolus immediately after tooth extraction or tooth loss due to trauma.

Delayed implantation is the installation of an implant after 6-8 weeks after tooth loss. Then the alveolus is completely covered with mucosa, but the bone is not formed and completely remodeled.

Late or late implantation is the installation of an implant in the jaw when the bone and soft tissue have completely healed. This happens six or more months after the tooth is lost.

Before implantation, you should choose the number of implants, the type, decide on the diameter and length of the implant. Data on the choice of implant should be entered either in the patient's record or in the computer.

The implant is sterile, in a glass bottle, with a label with the serial number, diameter and length of the implant, with an indication of the expiration date.

It is important for all implant systems that they are easy and simple to install and that they are easy to remove in case of failure, as well as that they do not damage the residual jaw tissue too much.

The simplest implant is the best.

Place of installation of the so-called the "receiving" region does not always provide ideal conditions for implantation. This primarily refers to the low floor of the sinuses and nose in the upper jaw and the high position of the mandibular canal and mental opening (sometimes located on top of the ridge) in the lower jaw. Today, these problems are solved by applying new surgical techniques (raising the floor of the sinus-sinus-lift surgery or transposition and lateralization of the inferior alveolar nerve).

Knowledge of the anatomic-topographic relationships and bone structure at the implantation site is of crucial importance for successful implantation.

The height and width of the alveolar ridge, bone structure and topographic relationships are decisive when it comes to the implant site. Experience has shown that the symphysis and molar area in the lower jaw and the area up to the second premolar in the upper jaw are particularly suitable for implantation. The most unfavorable bone for implantation is the area of the tuber of the maxilla.

Also significant is the presence of a firm, keratinized mucosa on the alveolar ridge. If there is no keratinized gingiva, it is necessary to perform a free mucosal transplant.

Implants are installed using a two-phase and one-phase method.

The two-phase implantation of the implant involves covering the implant with a mucoperiosteal flap and leaving it at rest for four or six months. In the second phase, the implant is revealed (reoperation), wait for the soft tissue to heal and proceed to the fabrication of the superstructure.

Some systems (ITI, steri oss, osseotitis) are implanted in one phase, because they are not covered by a mucoperiosteal flap, and for them it is recommended to rest in the bone, so a suprastructure is made. Today, with a special treatment of the implant surface, and depending on the quality of the bone, its resting time is shortened to 6 to 8 weeks.

Implants that are immediately or very early loaded are installed in one phase, such as Linkovv leaf, Lederman, Tramonte, Heinrich, bicortical, Kiss-Bauer, Muratori screw and a number of others. Bone quality and surface treatment have a decisive influence on their survival.

Whenever possible, a longer implant with a larger diameter should be substituted for a shorter and narrower implant. The prognosis for short and narrow implants is the worst, so failures are most common with implants shorter than 10 mm. Therefore, six or eight millimeter long implants are used only in special situations - a close relationship between the nose, sinuses and mandibular canal.

The loss of one tooth from the incisor region of the premolar and molar was solved by making a fixed prosthetic work. Today, it is recommended that a tooth, extracted or lost due to trauma, be replaced with an implant after several months of bone healing, but also with an early and delayed immediate procedure.

Installing an implant in the area of the upper front is much more demanding than installing it in the area of the molars.

Aesthetic problems are most often related to teeth in the upper front, especially when the inclination of the implant is more labial.

Receding of the gums in the area of the upper incisors occurs when there is bone loss or the labial lamella is severely thinned during the preparation of the implant bed.

Also, the low attachment of the frenulum of the lips and the line of ridge atrophy cause receding gums. That is why it is very important to pay attention to this during implantation and pre-implantation surgical preparation.

The distance of the tip of the implant to the sinus, nose and mandibular canal should be one to two millimeters.

The "safety zone" must be respected when implanting in the lateral areas of the lower and upper jaw. On the other hand, Bronnemark, as well as many other authors, claims that in the upper jaw the implant can be placed above the border of the sinus floor, provided that the membrane is not injured. They believe that the created hematoma organizes and further organization creates a solid bone callus.

If two implants are placed in the lower jaw, the alveolar bone is measured with a vernier in the mesiodistal direction (direction) so that the implant beds are made in the appropriate place. For example, if two implants are placed in the intermental area, the distance must be 12 mm from the previously marked center on the alveolar ridge.

It is sufficient to install two implants in the lower edentulous jaw, and four in the upper jaw, which is the minimum number of anchors for making prosthetic work. This attitude stems from differences in the quality of the bones of the lower and upper jaw.

For cylindrical implants, the width of the bone should be five millimeters, and for leaf implants 2.5 mm. For implants with a diameter of 3.3 mm, the ridge width should be from 4.5 to 5 mm, and for diameters of 3.75 and 4.1 from 5-6.5 mm and extremely large implant diameters are understood to require a much wider ridge - at least 7 mm.

The ridge height for cylindrical implants should be 10 mm, and the diameter 3.3-4 mm.

Solid screw implants are more commonly used because they can rarely fracture. They are easy to install, they are particularly mechanically stable and after correct installation they are always primarily stable.

Today there are shorter and longer implants that have specific indications. Also, implants of smaller and larger diameters are made, which are used in certain indications (minimum width of the alveolar ridge of seven millimeters). Six-millimeter long implants are used when the height of the ridge is insufficient, but in combination with longer implants.

Finally, the diameter of the implant is chosen according to the width of the alveolar ridge, and the length according to the height of the ridge. Satisfactory ridge height and width and good bone quality are thought to ensure an implantation success rate of 95-100%.

The distance between the two implants is 4 to 7 mm. It primarily depends on the diameter of the implant, because the minimum distance between them must be 3 to 4 mm.

The distance from the center of the implant to the cervical part of the adjacent tooth must be 5 mm, between the center of two implants 7 mm and from the center of the implant to the natural tooth (when making a bridge) the distance must be 11 mm. The distance between the two implants and the teeth as bridge anchors is 19 mm (18).

The minimum distance between the installed implant and the adjacent tooth should be 0.25 to 1 mm, which ensures that the periodontal membrane is not injured. This is especially important for the marginal part of the periodontium, because otherwise bone resorption and implant loss always occur.

Around the implant on the oral and vestibular side, the thickness of the bone after installation must be at least 0.5 mm.

During installation, the angle and direction of the drill should be constantly controlled in order not to injure the outer or inner cortical lamella.

During operation, drills are used in a bottom-up direction, at a reduced speed, and without pressure, in order to avoid the formation of a conical bed and to remove bone chips. Bone shavings should be collected to be mixed with bone substitutes in case of dehiscence during implantation.

The drills are standardized to match the length and diameter of the implant body. After preparing the bed, its depth is checked with a gauge.

While working in the bone, there is more or less resistance, no matter how new and sharp the drills are. The lowest resistance during the production of the tray is in the tuber, and the highest in the intercanine region of the lower jaw.

When the implant is inserted, it happens that the drill, after perforating the compact, passes through the spongiosa very easily, without resistance. In these cases, it is necessary to install one of the self-tapping implants.

When the compact is mostly dense in structure, the bed should be made with a sharp, new drill, otherwise overheating and early loss of the implant will occur.

All researchers and practitioners believe that overheating of the bone during the formation of the bed, along with high pressure during installation and premature loading of the implant, most often causes migration of the epithelium apically, which compromises the implantation in the early healing phase.

During installation, placement in the bed, no greater force should be applied, especially when the implant is hammered in (cylinders). This is especially important with implants that are coated with hydroxylapatite or plasma coated with titanium beads or powder. In this way, their fine microstructure, the surface, is damaged, which causes its loss. If this happens, it is necessary to install a new, undamaged implant.

Implant loading can be done immediately, and more often from two months to a year. It primarily depends on whether it is the lower or upper jaw, on the area of the jaw where it is implanted and the type of pre-implant surgical interventions, ridge augmentation, sinus floor elevation, vestibuloplasty, securing the attached gingiva, type of implant, immediate or late implantation and other reasons.

Implant loss can be "early" or "late". With two-phase implants, early loss means loss before prosthetic work is made, while with one-phase implants, early loss means loss of the implant in the first two to three weeks.

The primary loss of the implant occurs during the first year and is most often caused by a surgical error - dehiscence, overheating of the bone during the preparation of the bed, problems during healing, injury to the adjacent tooth, the appearance of instability, especially when short implants are installed. All of these are so-called iatrogenic reasons.

Secondary implant loss is primarily a consequence of poor hygiene, plaque accumulation, infection and incomplete fusion to the bone, eventual fabrication of a prosthesis that is subject to soft filling (trauma), as well as incorrectly performed definitive prosthetic replacement.

The site, localization of the implant after the healing phase can often be determined by inspection or palpation or probing. Today, the so-called: implant locators under the mucous membrane of the alveolar ridge are in use in the world. The exact location of the implant (sound) is determined by pulling the locator across the mucous membrane.

The surgical template is used in the second phase (reoperation), because by placing them in the patient's mouth, the place where the implants are inserted is accurately detected, they are easily surgically revealed and caps are placed for healing soft tissue.

The exploration (discovery) of implants in the second, surgical phase can be done with sharp trepan knives, for single use, which exactly correspond to the diameter of the installed implants. The implant can be exposed by making two parallel incisions in the anteroposterior direction, the length of which should not exceed the diameter of the implant.

Sometimes the healing cap can perforate the keratinized gingiva but does not threaten the survival of the implant. However, due to the possibility of infection around the implant, it is recommended to cut off the entire gingiva over the healing cap.

Trepan-borers of a certain inner or outer diameter can be used for explantation.

It is absolutely necessary to ensure aseptic working conditions for implantation. The patient cannot protect himself from his own oral flora, so everything that comes into contact with the patient must be completely sterile. Sterilization of instruments and implants is done in a dry sterilizer or autoclave. Before sterilization, the instruments should be cleaned, immersed in a disinfectant that breaks down the proteins on the instruments, washed with alcohol - which removes grease, and dried. Manual, mechanical or ultrasonic cleaning is most often applied. Ultrasonic cleaning of instruments is much more efficient.

Preoperatively, good hygiene is recommended, rinsing with chlorhexidine several times a day for two minutes.

Patients should be sedated, if necessary, and antibiotics should be prescribed, not as a routine. If multiple implants are inserted in the lower and upper jaw and if tissue regeneration is being performed, it is necessary to prescribe antibiotics. It is understood that when choosing an antibiotic, penicillin is the first choice, and in the case of penicillin allergy, clindamycin, erythromycin, doxycillin or another antibiotic that does not have a cross-allergic reaction with penicillin is recommended.

In postoperative treatment, it is essential to prevent swelling and pain. Cold compresses and, if necessary, analgesics are recommended to the patient.

Perfect hygiene of the mouth and the implant (teeth) is especially important for the survival of the implant. This includes brushing your teeth after eating, using an interdental brush and floss, and rinsing your mouth with chlorhexidine (Hibedex).

After installing the implant, it is necessary to constantly monitor the patient.

All that is known when it comes to other surgical interventions and refers to the choice and type of anesthesia, also applies when it comes to the installation of implants.

In other words, general and local anesthesia can be applied. The largest number of implants are inserted under local anesthesia, with possible intravenous sedation. General anesthesia is possibly applied when subperiosteal implants are performed, although sedation and local anesthesia can be combined here as well. The indication for general anesthesia can also be a personal request of the patient.

Numerous enthusiasts from the field of preprosthetic surgery, and for the last few decades implantology, have been looking for solutions for successful tertiary prevention of patients. Pre-prosthetic and pre-implantation surgery, both in their own way, aimed to provide a better residual alveolar ridge for the acceptance of better quality prosthetic work. In the center of interest were always the state of soft and bone tissue, the presence and arrangement of the remaining teeth in the upper and lower jaw, as well as interjaw relationships.

From time to time, some of the procedures of pre-prosthetic surgery have been tried to solve the problem of complete toothlessness in patients. Thus began the application of many methods of vestibuloplasty (Kazanian, Hali and O'Steen, Obvegezer, Tirsh, Trauner, Gaidwell, etc.) of the labial and buccal vestibule with the basic idea of changing the relationships of the mobile and immobile mucosa if there is enough bone. Free bone autografts were also performed, which do not give final results in the rehabilitation of patients. Unfortunately, many of these patients do not achieve favorable conditions for making a satisfactory prosthesis. In recent decades, ridge augmentation has been done with various alloplastic materials or mixtures of bone autografts and alloplastic materials. In this way, the height and width of the alveolar ridge can be increased, which, applying the principle of aqueous tissue regeneration, ensures, after some time, a very successful implant installation.

Today, intensive efforts are being made to rehabilitate the patient with prosthetics as soon as possible after implantation. The first proponent of this method of rehabilitation was Lederman in the seventies. This, first of all, depends on the quality and quantity of the bone and the treatment of the implant surface, which is why the installation is much more often recommended in the lower jaw.

The possibilities of prosthetic solutions on implants are very large and varied, starting from a solo crown to treating completely toothless patients with fixed works.

The superstructure on implants can be fixed, mobile or conditionally fixed. It is especially challenging to create fixed prosthetic works in patients with complete edentulism of the upper and lower jaw. The first attempt of this kind was made by Bronnemark in 1965 in the lower jaw, where the fixed work was still in excellent function after 15 years. Today, working longer on the care of such patients, he presented very successful results even after 25 years. It is considered that for a fixed circular bridge in the upper and lower jaw, at least six implants with a length of 12 mm and a diameter of 4 mm should be installed. However, in practice, there are rarely patients in whom these conditions can be met, so compromises are made, when it comes to the length and diameter of the implant. The alveolar ridge does not have the same height along its entire length, so in such cases, several implants can be installed, the length of which does not have to be the same. On the other hand, the second condition - the diameter of the implant of 4 mm, should definitely be respected because fractures of implants with a diameter of 3 mm and 3.3 mm in such constructions often occur during fixed works.

The pronounced disparity of the installed implants, whether they incline palatally, mesially, and distally, creates difficulties in prosthetic work. Sometimes it is possible to solve this situation with an angled superstructure, making a mobile instead of the planned fixed work, an internal telescope crown, but more often it happens that an aesthetic, hygienic and functional superstructure cannot be made. Therefore, during the installation, you should take care of the positioning of the implant bed and control the installation of each subsequent implant, setting the parallelism indicator.

If the implants are placed very close, prosthetic work is difficult to do. Therefore, for hygienic, static and aesthetic reasons, one implant should often not be included in the prosthetic work (put on a healing cap).

Labial and lingual inclination of implants are equally unfavorable for correct operation. In both cases, the superstructure aesthetically and phonetically does not satisfy the patient. The solution can be the installation of an implant or a full substructure, abutment, at an angle of 5°, 10°, 15° or more degrees.

Retentive elements of prosthesis stabilization are bars, balls, telescope crowns, ceka atechmeni, factory bars, cast milled rails and many other types of retention.

When the bar is used as retention on implants, it must not be too extended in the distal segment of the lower or upper jaw because it breaks. This requires the creation of a new retention bar and a new prosthetic work.

The superstructure can be fixed by cementing, a conditionally mobile connection (a screw that the doctor removes) and a mobile connection using a telescope-crown and attachments.

Special instruments are used for the installation of implants. In fact, each type of metal and ceramic implant requires the use of instruments that can only be used for that method. There is no universal set of instruments, but they are designed specifically for each implantation system.

In addition to the standard surgical set, the following should be provided for implantation: a device with internal cooling (physiodispenser), knee and handpiece, as well as a set of special parts and instruments.

The physiodispenser is a high-powered device with a built-in pump that ensures a constant flow of saline solution.

The elbow and the handpiece are designed so that they can reduce the number of revolutions, with constant internal cooling. The optimal number of revolutions for implant installation is 700-1000 rpm. If necessary, the number of revolutions can be increased or decreased even to four, six or ten revolutions per minute. With such a small number of revolutions, the implant can be screwed into the socket. By applying the physiodispenser according to this regimen, thermal and mechanical damage to the bone is excluded.

The set of special instruments contains several standard reamers for making the bed, depth pins, bone reamers and orientation pins for parallelism. In the set there are also attachments suitable transmission, with which the implant is manually or mechanically screwed into the socket.

According to the method of installation or anchoring, there are four basic groups of implants: transdental, endosal, subperiosteal, intramucosal.

This division was made according to the type of tissue in which the implant is placed

Transdental implants over the teeth and retention in the bone have the function of tooth stabilizers.

Endosal implants are embedded in the bone tissue of the lower and upper jaw.

Subperiosteal implants are placed under the mucosa and periosteum on the bony tegmentum of the upper and lower jaw.

Submucous implants are retained in the mucous membrane of the palate, and are applied in the upper jaw of completely edentulous patients.

According to the design or shape of the implant, there are cylindrical, screw, leaf, double leaf, granular, ramus implants, trarismandibular, disc implants, etc.

Subperiosteal implants are divided into partial and total.

Endoosseous implants are most commonly used today. It is estimated that in the structure of implant installation they are represented in 95% of cases.

According to the surgical technique, implants are divided into one-phase and two-phase. Single-phase implants are not covered by a mucopenosteal flap. Two-phase ones are covered with a lobe and remain dormant for four and six months, respectively. In the second stage of reoperations, they are freed and prepared for the creation of sur^astnicture.

This group of implants, among others, includes the Bronnemark system, IMTEC, IMZ, Pitt-Easy, Biooss, Steriooss, Integral, Biomax, Dyna implant, Mac system, Frialitt, Jota, Ankvlos, Đone system, and a number of other systems.

In this group of systems, there are implants that can be implanted in one phase, but remain at rest in the bone for four or six months. All these systems heal by osseointegration.

On the other hand, some systems - leaf, screw, needle - are installed in one phase and are loaded immediately or early as structural supports. Because they are burdened like this and are not fully integrated, the percentage of failure is also very high.

The next division of implants is into one-part, two-part and multi-part depending on their purpose.

Implants are divided into metallic and non-metallic.

Metal implants are made from commercial titanium, titanium alloys, tantalum, niobium and chromium-cobalt-molybdenum alloys.

Non-metallic implants are made of aluminum oxide, monocrystalline form (sapphire) and polycrystalline form (alumina). They are made in the shape of a tooth root (screw, cylinder) or as a sheet. This includes tibigen implants, Sandhaus, Bioceram, Biolox, Brinkman, Vajda and others.

Transdental implants were made from ceramics and a combination of ceramics and alloys.

The group of non-metallic implants includes materials of human and animal origin and synthesized alloplastic materials. They are applied as a bone substitute to improve the anatomical configuration of the residual alveolar ridge (augmentation, rx>dnMniran and uneven ridge, prevention of ridge atrophy). These include Biooss, hydroxylapatite, algipore, obsorvite, Ceros, HTR and a number of others.

Non-metallic implants are made of carbon and polymer.

Transdental implantation is a procedure by which a tooth is stabilized and fixed in the teeth and bone of the upper and lower jaw by means of an implant. Transdental implant, transfixation, transdental fixation and endodontic enosal implant are synonyms that are most often used in the literature. This method has been successfully applied for dozens of years.

The main goal of applying transdental implants is to lengthen the root of the tooth, that is, to improve the relationship between the clinical crown and the root of the tooth. Those ratios are satisfactory if the crown-root ratio is 1:1, even better 1:2 or 1:3.

Since the first transdental tooth fixation was applied (Strock and Strock 1943), a large number of authors in our country and around the world have created and applied different types of these implants.

Transdental implants do not communicate with the gingival space, oral fluid and microorganisms of the oral cavity. Therefore, they differ from the so-called "open" implants, which communicate with the mouth, so it is considered that they are installed under the most favorable conditions. It is understood that these facts recommend them for everyday, routine practice, because they belong to the so-called "physiological implants".

The success rate of transdental fixation is considered equal to the success rate of root resection.

Transcendental implants are indicated for the following cases:

- tooth root fractures; - internal root resorption; - when the loss of the tooth support apparatus is greater - horizontal resorption where surgical periodontal treatment methods are not sufficient for tooth fixation; - external root resorption; - periapical processes and cysts that cover one third or more than one third of the apex of the tooth root; - fause rout in the middle third of the root; - anomalies of root growth and development, root after dissection, hemisection, replantation and transplantation, residual roots of insufficient length, etc. - important teeth for prosthetic replacement, where strengthening, "anchoring of the teeth" is possible.

Contraindications for installing transdental implants do not differ significantly from contraindications for installing other types of implants.

Transdental titanium implant (111 sec. Perović-Mandić) with self-tapping threads along the entire length, made of titanium 99.85% pure. The length of the implant is 3.5 cm, with a diameter indicated on the head of 1.0; 1.1; 1.2; 1.3; 1.4; 1.5 and 1.6 millimeters. The slits are trapezoidal in cross-section, 0.1 mm deep and 0.3 mm wide. This shape, depth and spacing of the vines significantly affect the primary stability of the implant. The titanium threads for this implant are forged, drawn, ground and tapped.

Retroalveolar imaging, orthopantomography (OPG) imaging, profile imaging, and tomographic and CT imaging are used for planning and control of transdental implant placement. The most commonly used imaging techniques are retroalveolar and profile imaging. They can be used to assess the state of dental and bone tissue in the area of the apex of the tooth, i.e. the length of the subapical part of the bone.

It is extremely important to know the length of each tooth separately. The length of the subapical part of the bone should be added to the known length of the tooth, and accordingly, determine how much of the implant goes into the dental and bone tissue. Collected, these lengths should be transferred and marked on the implant so that it is known exactly how much it should be twisted.

Tooth trepanation is performed from the palatal, i.e. lingual, side. In the upper front, considering the rigidity of the implant and the direction of the canal, trepanation should often be done from the labial side, more incisally. During the expansion, the root canal should be constantly flushed. Apical ramifications are also cleaned in this way. The root canal is expanded with Kerr-needles and Boitelrock. The Kerr-needle channel expands gradually, from smaller to larger numbers. The diameter of the expansion channel for implant installation should be at least the diameter of the implant, i.e. one millimeter. In other words, the expansion of the root canal depends on the diameter of the implant. A larger diameter of the implant requires expansion of the canal with a Kerr-needle 100, 110, 120, 130 or 140. The definitive shape of the canal during expansion is better done with Kerr-needles, because a more favorable, conical shape is obtained, than with Beutlerok, which gives a cylindrical shape to the canal.

The seat of the Hi osteotomy in the cancellous bone is made either with a regular or a special Beutlerok that is intended only for this purpose.

After the test, i.e. removing the implant from the root canal and bone bed, it should be thoroughly cleaned and dried.

After the implant has been tested, it is removed from the canal and bone, a gauge with a diameter of 0.8 mm, the same length as the implant, which is graduated in 1/2 cm increments, is placed in the socket.

The length of the canal and the length of the bed in the bone should be transferred from the gauge to the implant and marked with a drill, sterile pencil, felt-tip pen or methylene blue, or a rubber collar should be placed at the level of the incisal edge or the cusp of the tooth.

The root canal is filled with cement that is applied with a probe or a plastic instrument to the implant, but only up to the length of the root canal of the tooth.

Transdental implants are installed using the apically open and apically closed method.

The apically open method involves surgical opening when implantation is performed under direct eye control.

It is most often indicated when there is a larger periapical process - cyst and granuloma, root fracture in the apical third, internal and external resorption in the apical third of the root, foreign bodies in the root canal, root canal obstructions, etc.

Apically open method is combined with root resection.

In the apically open method, different incisions can be used. (according to Partch, Remmiller, Peter and others)

The type of incision depends on the size of the process, number of teeth, presence of fistula, frenulum, anatomical relationships, etc.

After fenestration with a fissum drill, root resection is performed and the penapical pathological process is removed. Root resection is always performed at a right angle.

When the root canal is widened enough, a bed is made in the bone with a Boitelrock, that is, two to three millimeters are inserted into the spongiosa. The bed is made under the control of the eye intercortically in the cancellous bone. The initial bed in the bone should be in the same axis as the root canal of the tooth.

After the osteotomy, the selected implant is inserted through the root canal, placed in the initial socket and screwed. The tip of the implant is placed up to the compact in the upper jaw towards the nasal aperture, the lower border of the sinus or the zygomatic bone, and in the lower one it can be placed all the way to the cortex of the base of the jaw. During the screwing of the implant, resistance is easily felt when the tip of the implant reaches the cortex. If the bordering, compact part of the bone is overstressed, the implant is in the cavity and becomes unstable.

After this procedure, the implant is removed, a graduated gauge is placed, diameter 0.8 mm, and a control retroalveolar X-ray is taken.

In this way, the position of the top of the implant is precisely determined. If it does not reach the right limit, it should be screwed deeper or if it is placed deeper, it should be returned lower. When the implant is placed too deep, it is practiced to apply a second implant with a wider diameter, at least by one or two parts of a millimeter. The value of the length of the bed in the tooth and bone is transferred from the meter and recorded on the clean and dried implant.

Cement is applied to the part of the implant that corresponds to the length of the root, with a probe or a plastic instrument.

Then the implant is screwed to the marked length. When a good filling is done, cementum appears on top of the resected root. When the cement is firmly set, the excess is removed from the tip of the root through the trepanation hole.

Amalgam must never be used as a filling, because corrosion always occurs which compromises the implantation!

The apically closed method is most often indicated when it comes to strengthening periodontopathic teeth, root fracture in the middle third, internal resorption located in the first two thirds of the root, developmental anomalies of root growth, etc.

Trepanation of the tooth, complete expansion of the root canal, creation of a bed in the bone, measurement of the length of the tooth and the bed in the bone, hemostasis, cleaning, drying of the canal and trial of the implant are performed as in the apically open method.

At the same time as transdental implantation, when there is periodontal disease, it is possible to perform other therapeutic procedures. Before the operative procedure, it is necessary to remediate the infection from the periodontal pockets, remove soft deposits, subgingival calculus and concretions, perform flap surgery and then proceed to transdental implantation.

The flap of surgery, whether it is performed before or during transdental fixation, significantly affects the functional reintegration of the tooth in which the implant is placed.

The success of transdental implantation depends, above all, on good planning. As with many other surgical interventions, mistakes and complications are possible during implantation. In fact, no stage during implantation excludes the possibility of error or complication.

A poorly set indication, poor surgical technique and creation of an inadequate superstructure, as a rule, lead to implantation failure.

Injury to the nasal cavity, sinuses, and mandibular canal is an error that occurs due to poor evaluation of the X-ray image and occurs during the creation of the bone bed and the screwing of the implant.

Injury to the contents of the mandibular canal, especially the mandibular nerve, is characterized by the appearance of sharp neuralgiform pain, which radiates and may indicate the onset of secondary trigeminal neuralgia. In those cases, the implant should be explanted.

A forced apex with filling paste can occur when both implantation methods are performed. Excess bonding agents, composite or cement, in the periapex must always be removed.

It is understood that post-operative edema, hematoma, pain and infection can occur. All these complications are treated in a well-known, standard way.

In order for the implantation to be successful, it is necessary to do the following:

good preimplantation preparation;

the right indication;

mechanical and chemical processing of root canals;

provide a bed in the bone;

the axes of the root canal and the bed in the bone must coincide;

dry the root canal and implant;

put cement on the part of the implant that corresponds to the length of the root;

place the implant deep enough until resistance is felt when twisting;

wait for the cement to set;

remove excess cement from the periapex;

shorten the implant;

if necessary, carry out immobilization;

to fill the cavity, and

perform an X-ray examination.

The technique of installing a screw or screw implant is, regardless of the existence of a number of systems, in principle either similar or equal. The same instrumentation can be used for most systems.

Once one method is described, all other installation techniques are understandable and comprehensible. For the installation of spiral (screws) or screw implants, a flap can be made, but the implantation can also be done without forming a mucoperiosteal flap. They are installed individually, when one tooth is missing or as supports for larger structures. The installation technique should be gradual, with minor trauma to the mucopenosteal flap and bone tissue. The incision is made either only in the middle of the alveolar ridge or at an angle forward, or the alveolar ridge is exposed completely from the mucoperiosteal covering, i.e. it is peeled both lingually (palatally) and buccally. After the flap is excised, with a special drill that is narrower than the diameter of the future spiral implant, the middle of the alveolar ridge is targeted and at a right angle to its horizontal plane, a perforation is drilled for the length of the future screw of the implant. Vertical pressure should be applied on the finger wrench. After the bone chips are washed out, the perforation is formed with pre-screws with four, five or more threads depending on the number of threads on the implant to be installed. The number of threads on the pre-screw corresponds to the number of threads on the implant. The implant is 0.25 microns wider than the pre-screw The posterior thread of the definitive screw should enter one millimeter below the cortical part of the bone. It is especially important during the installation to maintain the direction and dose the force in order to save the cortex from the load. The wound is sutured and after removing the sutures, definitive prosthetic work can be done.

Tramonte (1957) created the original, self-tapping screw implant. Installation of this implant requires an incision, the formation of a flap. Then, with a special initial drill, the cortical part of the bone is trepanned to a depth of several millimeters, and with a conical drill, with a low number of revolutions, the surgical alveolus is shaped. With a digital and then a manual wrench, which achieves greater power, the pre-screw is placed and later, the implant is screwed in the same way. The implant is wider than the pre-screw, while the number of threads on the pre-screw and the implant is the same.

The relatively successful ones include Tramonte, bicortical screw implants, Oraltronics, KISS-Bauer system, Chercheve, Heinrich, Muratori screw and others.

The bicortical screw (Oraltronics) is a single-phase implant that can be implanted immediately after tooth extraction or later. With special drills, of a specific profile, and with the help of a finger and hand wrench, the implant is installed to reach the cortex of the bone. It is used as an anchoring screw in a bridge or with intercanine edentulous ridges and after individual tooth loss.

Today there are many modifications of screw implants

The bed for some of them is made blindly, without forming a mucoperiosteal flap. This method is done if the alveolar ridge is wide enough. In such cases, the bed is made with an initial and triangular drill and the implant is screwed with a finger and hand wrench. Today, drills with internal cooling are used for these purposes, which ensures a better success of implantation.

These implants are immediately loaded, they heal fibroseally. Early loading is no guarantee of success Success is even less if you do not work with internally cooled drills.

It is very risky to load these implants immediately after installation, because early and especially late failures are not excluded.

The doctor does not always have to respect the patient's requests. That kind of compromise usually leads to failure.

In 1970, Lederman created the TPS screw (Titanium Plasma Spray) intended for the prosthetic treatment of the edentulous lower jaw. Four implants are placed in the smiphyseal part of the lower jaw, which are connected to each other with a factory overhang. The screw is self-tapping, 8 to 14 mm long, and 4.1 mm in diameter.

The beds are prepared with special instruments, mostly by hand. First, the initial part of the bed is perforated with an initial drill, with abundant cooling. Since the screw is self-tapping, the bearing walls do not need to be tapped. The advantages are single-phase, single-part and that the ptothetic work is made immediately after installation.

Success rates for screw implants range from 63% after four years, to even 50%, to 93% after seven years.

The Lederman screw, which is considered to be of the highest quality, has a success rate of 90% after eleven years.

Installation of one-phase implants (Linkov, Tramonte, Bicortical, Kiss Bauer and a number of others) requires good bone quality, as well as satisfactory height and width of the alveolar ridge. It is considered that the installation of one-phase implants is justified if the implants are connected to each other with crossbars or are immediately covered by suprastnictures.

In the 1970s, Schreder and colleagues developed the ITI system, which is one of the most prestigious systems today. It is produced in three basic types: hollow cylinder, hollow screw and solid, solid screw. All these variants are one-piece or two-piece. A special contribution is the so-called SLA implant (Sand-blasted, Large grit, Acid etched) which, depending on the quality of the bone - good density, spongiosa, is loaded in six or 12 weeks.

Implants are of different diameter and length. In use are diameters of 3.3 mm, 4.1 and 4.8 mm, and lengths of 6,8,10,12,14 and 16 mm.

Drills with a diameter of 2.2, 2.8, 3.5 and 4.2 millimeters are used for implant installation.

The number of revolutions, according to the manufacturer's recommendation, depends on the diameter of the drill, smaller diameter higher number of revolutions (800), larger diameters of 3.5 and 4.2 millimeters lower number of revolutions (400). All drills (of newer production) are longer by 0.4 millimeters (previously 1.75) than implants, which should be taken into account during RO diagnostics. Drills are marked every two millimeters with notches - lines starting from six to 16 millimeters.

The tool consists of a transmission, a right-angle wrench, a torque wrench, a gedora, a bearing cutter, a depth gauge and a parallelism indicator, (diameter 2.8 and 3.5 mm) an Allen key

This set is used for the TPS full screw of older production. Since some time ago, changes have been made so that the implant is removed from the vial with a gedora adapter (and not by screwing the transmission). At the end of the installation, the implant is fixed with a spanner (New handling) and the adapter is removed with a gedor. In this way, the solid screw TPS (Titanium Plasma Spray) and the latest SLA implant are now installed.

Solid TPS and SLA implants with a diameter of 4.1 mm and 4.8 mm are used for the production of all fixed and mobile superstructures. Implants of these diameters can be combined with the fact that the ridge width must be at least five or seven millimeters. The combinations are all the more justified because the 4.8 mm implant diameter does not have all lengths (6, 8, 10, 12 and 14 mm), while the 4.1 mm diameter implants have longer lengths. Implants with a diameter of 4.8 mm are mostly used in case of toothless atrophic ridges and loss of one tooth in the lateral areas of the jaws.

SLA implants are most commonly used today because they heal faster. They are 3.3, 4.1 and 4.8 mm in diameter (full screws) and as hollow cylinders of 3.5 mm in diameter and 8, 10 and 12 mm in length.

Solid screws are also in use. WNI (Wide neck - wide neck) diameter 4.8 mm, neck width 6.5 mm and length 6, 8, 10 and 12 mm and solid screw implant so-called. NNI (Narrow Neck) diameter 3.3 mm, neck width 4.8 millimeters and length 8, 10 and 12 millimeters. They are applied in the soft region of the lower and upper jaw when the ridge is 6.2 millimeters wide.

Both implants, wide and narrow neck, are often indicated as solo implants or in combination with 4.1 mm diameter implants.

ITI created, "Estetik plus", ITI-TE and ITI Mono Type.

Estetik plus has the form of a cylinder, a hollow cylinder at an angle of 15 degrees and a neck width of 4.8 mm. Also in use is a solid screw with a diameter of 3.3 millimeters and a neck width of 4.8 millimeters. Special short drills and healing caps are used for the installation of these implants.

The bed is made 2 mm longer than the implant so that the polished part (the neck of the implant) is under the gingiva.

ITI - TE SLA, a self-tapping implant was created for immediate and delayed immediate implantation. The dimensions of the implant diameter are 4.8 and 6.5 mm. In the apical third, the diameters are 3.3, 4.1 and 4.8 mm. In this way, it is achieved that the sections of the implant correspond to the shape and dimensions of the alveolus of the extracted tooth. Their length is 8, 10, 12 and 14 mm. The bearing is made with drill bits 2.2, 2.8, 3.5 and 4.2 mm. The implant is dimensioned to provide primary stability, the thickness of the connecting and oral compact of the alveolar limbus of at least one millimeter and often leaves no space between the walls of the alveolus and the body of the implant.

The ITI Mono Type SLA implant has a diameter of 4.1 mm and a length of 8, 10, 12 and 14 mm. It is used in edentulous jaws that have satisfactory bone quality and quantity. Only two drill bits, 2.2 and 3.2 mm in diameter, are used to make the bearing. Four implants are installed by hand and by machine, and prosthetics are made immediately after the installation of the implants.

The indication area of ITI implants is very wide, starting with solo crowns, fixed bridges, retention elements for partial and total dentures and aesthetic crowns.

Indications depend on the length and diameter of the implant. The diameter of 3.3 mm is installed in a ridge of a smaller width but does not bear heavy loads. Therefore, in the lateral areas, the fork is not used as an individual structure support. It is used in combination with a diameter of 4.1 mm connected in the construction or in an edentulous jaw (four implants) which must be connected by a bar.

The incision is made in the middle of the ridge and the relaxation incisions are extended from the oral and vestibular side. The entire ridge should be exposed and accessible. Osteotomy is done if there are irregularities on the ridge and if the ridge needs to be widened (taking into account its height).

The places where the implants will be placed are marked with a round drill of diameter 1.4, 2.3 and 3.5. The implant bed is made with drills of diameter 2.2 mm, 2.8 mm, 3.5 mm (for diameter 4.1) and 4.2 mm for implant diameter 4.8 mm. During operation, the drills should be cooled with a sterile physiological solution, while strictly paying attention to the number of revolutions. A higher number of revolutions causes thermal and mechanical damage to the bone. The bed is washed and its length (depth) is measured with a coded gauge. The walls of the bed should be cut. The threader is initially screwed by hand and then with a gedor to the end of the bed. If during cutting there is no great resistance in the first third of the bed (a sign that the bone is spongy), the implant should be decided immediately. The implant is removed from the ampoule with a gedora adapter and manually screwed in until resistance appears.

The implant is finally placed with a gedor, up to the polished part. It should be noted that when using the 1 Gedora slicer, the operative field should be cooled with saline solution. A healing cap is placed on the implant. Finally, sutures are placed.

If necessary, for better adaptation of the flap, the soft tissue should be circumscribed against the implant.

For the installation of cylindrical implants, an incision is made in the middle of the ridge and the place on the bone where the implant will be installed is marked with a round drill. With a short spiral drill, the cortical part of the bone is perforated without pressure, with mandatory cooling with a saline solution, and forms a bed for the implant. Then, depending on the type of implant, a definitive implant bed is formed, washed well and the depth of the bed is checked, with the help of trepan or spiral drills, depending on the type of implant.

With a special tool, gears and keys, the implant is placed in the socket and with a gentle blow of the hammer on the special instrument, it is placed to the very bottom, so that the polished part of the neck is outside the bone. Both hollow, cylindrical and screw-implant are closed with a healing cap. Postoperative treatment is standard.

The advantages of the ITI system are the ability to maintain good hygiene of the supragingival part of the implant, a wide selection of implants, ease of installation, no reoperation (phase II), faster healing, simpler superstructure, etc. ITI implants with TPS (Titanium Plasma Spray) heal in three to four months depending on the quality of the bone (density) and the extent of spongiosa. The new SLA system heals in six to 12 weeks, which is why it is most often used.

Schroeder (1986) and Buser (1988) describe a good tissue response to ITI implants. They state that the epithelial attachment on the neck of the polished part of the implant is very similar to the attachment of a natural tooth.

Sreder further states that the bone apposition on the implant is completely free from the presence of connective tissue, which he described as "functional ankylosis".

The success rate of ITI implantation ranges from 88% to 98.5%. The assessment was carried out at various clinics in the world, so it is logical to conclude that in any case the percentage of success is very high, because in fact only at one clinic the percentage of success was 88% and at all others from 93.3 to 98.5%.

At the fourth ITI Congress in Germany in 2001, eleven-year results for 5,619 patients in whom 15,419 ITI implants were implanted were presented. Sooner or later, 267 implants were removed. The success rate was 98%. It was also stated that smokers lost the most implants - 71%.

In the early 1960s, Bronnemark began experimental and clinical research on the so-called implantation system. fixtures.

Bronnemark was the first to recommend the concept that the absence of fibrous tissue in the space between the implant and the bone is the key to clinical success in endosseous implantation. Bronemark et al consider it an essential condition for osseointegration that the endosal part of the implant be closed in the alveolar bone and unloaded in the so-called, three to six months after installation. in a functional state, which implies a two-phase installation procedure. In the first phase, an implant is inserted, which heals in the lower jaw for four months, and in the upper jaw for six months. In the second phase is the surgical removal of the implant as a preparation for the fabrication of the superstructure.

From him comes the definition of osseointegration as "obvious, direct contact or connection of vital bone tissue with the surface of the implant, without the presence of connective tissue". He, realizing that there is a solid connection between the implant and the bone and that the cushioning effect of the periodontium is missing, recommended the creation of a superstructure with certain mechanical properties and elastic components.

The Bronnemark implant is the best-controlled oral implant, both from an experimental and clinical point of view, with a success rate of 85-100% in the upper jaw and 93-99% in the lower jaw. This system is the best studied so far and has the most acceptable criteria.

Finally everyone admits that it is the best implant system in the world.

The indication area of these implants includes everything that is done in oral implantology, starting from a solo crown to the solution of complete toothlessness in the lower or upper jaw. Even more than that, because they created new types of implants with a special purpose.

Instrumentation and implants are expensive, so it is not surprising that there are strict requirements for the profile of experts, that is, their special education.

The instrumentation is excellent and diverse, which allows implants to be inserted manually and mechanically.

The drills are made of steel, marked every two millimeters with incised lines, starting from 7 to 18 millimeters and with diameters that correspond to the diameters of all implants.

Implants are made of 99.75% pure titanium. The length of the implant is 7, 8.5, 10, 11.5, 13, 15 and 18 millimeters. Only Mk III, 3.3 mm diameter and Mk IV, 5 mm diameter do not have all standard lengths

The diameters of the implants are 3.3, 3.75, 4 and 5 millimeters. The gauges are based on the "platform concept" - narrow (NP), regulation (RP) and wide platform (WP). From this concept it follows which implant should be used, which primarily depends on the width of the alveolar ridge.

Mk III are self-tapping implants that are implanted in patients with bone quality 1, 2 and 3. If the bone is extremely compact and solid, part or all of the implant bed should be tapped. On the other hand, when the bone is spongy, loose, the Mk IV implant should be used.

The surface of the Mk ITI implant is machined (highly polished surface) and TiUnit technique. The surface of the Mk IV implant was treated only with the TiUnit technique.

The TiUnit technique works osseoconductively, promoting better and faster union and significantly affects the primary stability of the implant.

During the last few years, many clinicians recommend the immediate, one-stage installation of these implants. For these purposes, implants whose surface is treated with the TiUnit technique are used, because much better results are achieved, especially when the quality of the bone, the amount of available bone and the installation technique are satisfactory.

The incision is made paraalveolar and separates the mucoperiosteal flap. If necessary, osteotomy is performed. The place where the implant will be installed is marked with a round drill (2 mm diameter). With a pilot and spiral drills of 2 and 3 mm diameter, on which there are engraved lines indicating the depth, the bed is made according to the length of the implant. Checking the depth and parallelism is done during the production of the bed. Only the initial part of the bed is widened with a specially designed edge drill (Counteborer) so that the implant with its neck part, immersed in the bone, rests completely on the walls of the bed. Tapping of the bed is done by machine at a reduced speed (from 20 rpm). Next, the implant driver (implant driver), star-shaped, hexagonal, is placed in the knee, which is used to remove the implant from the vial, insert it into the socket and screw it in with a reduced number of revolutions. When the implant is placed at the end of the bed, the work of the knee is automatically switched off.

This method of installing implants has been significantly innovated by the use of the so-called Stargrip instead of the implant carrier, with which installation is simpler and much more precise.

The healing cap is screwed in the same way, and definitely fixed with a hand wrench.

The mechanical installation of a 3.75 mm diameter implant is described here. Implants of other lengths and diameters are installed in the same way, only the profiles of the drill bits for making the implant bed are adjusted.

After four or six months, through an incision in the middle of the ridge, no longer than five millimeters, the implant is released and a cap is placed for the healing of the gingiva. The caps are 3 to 7 mm long, and which one should be taken depends on the thickness of the soft tissue.

In the second phase, the gingiva can be cut around the perimeter of the implant with a suitable instrument, which is in the tool.

Bronemark's team created two implants with a special purpose: the immediate provisional implant and the Zvgoma implant.

Immediate implants are 14 mm long and 2.8 mm in diameter. They are implanted directly in the same visit, with two-phase standard implants. They are placed between the healing implants until complete osseointegration. Immediate implants have a cap on which a provisional superstructure is made. After the healing period of the two-phase implants, explantation of the immediate and definitive prosthetic work is performed.

The Zvgoma implant is used in severe resorption of the alveolar ridge of the upper jaw as a relevant element of total denture stabilization.

By monitoring the success, according to the accepted criteria, over a period of several years, these implants showed ten years of stability of 95% in the upper jaw and 99% in the lower jaw. Such results, presented by many authors, are an unquestionable recommendation that this system is truly the best and so far unsurpassed.

Implant placement immediately after tooth extraction is called immediate implantation.

When immediate implantation is done, immediately after tooth extraction, there are always empty spaces between the implant and the alveolus, so they must be filled and covered with a membrane. It is understood that the wound, i.e. the implant, must be completely covered with a mucoperiosteal flap. Since this does not always give satisfactory aesthetic results, most doctors opt for delayed immediate implantation. Delayed immediate implantation should always be done when there is a periodontal abscess, fistula or marginal periodontal abscess. These and other conditions must first be remedied, and then, after 6 to 8 weeks, the implantation should be done.

Both immediate and delayed immediate implantation have advantages, the tooth can be replaced immediately or early, that is, the resorption of the ridge can be significantly slowed down or reduced. Some authors claim that 40 to 60% of bone loss is prevented in this way.

For this type of implantation, implants made of aluminum oxide-ceramics and two-phase and one-phase titanium implants are used. Certain types of single-phase screws can also be used for these purposes, such as bicortical, Tramonte, KISS Bauer, Muratori, Heinrich, Lederman and others.

Indications for their use are traumatic tooth extraction, advanced internal and external resorption, devitalized teeth that cannot be saved conservatively and surgically, and root resorption (traumatic, after replantation and transplantation, etc.)

Immediate implantation is primarily done after the loss of incisors, canines and premolars in the area of the upper and lower jaw.

A delayed immediate procedure is recommended for upper first molars when a palatal alveolus is used. It is also possible to work on lower molars, but it is necessary to use a wider implant (New ITI-TE implant).

Immediate implantation should be done if the height of the ridge is not less than eight millimeters and its width is not less than five millimeters.

Tooth extraction should be done with as little trauma as possible and, if possible, preserve the alveolar walls.

When applying immediate implantation, the bone of the alveolus should not be shortened, because a satisfactory aesthetic appearance will not be achieved.

After tooth extraction, the alveolus must be well cured to ensure a healthy bone cup.

Especially after extraction of periodontopathic teeth from the lower or upper front where two, three, four or even six implants can be inserted into the rest of the healthy periodontium in the anterior part. All other conditions must be met as if it were a normal implantation. This primarily refers to the condition of the residual ridge, the presence of dehiscence or fenestration of the alveolus, infection, relationship with neighboring anatomical structures, etc.

It goes without saying that the implants must have primary stability, which is achieved by deepening the alveolar cup, more apically, of course to the extent that the anatomical structures allow. In this way, a deeper bed is provided and a longer implant is installed, which is particularly important for the success of the implantation.

Immediate implantation can be done by taking closed extraction wounds (plasty according to Rerhrmann). The implant, bone substitutes and membrane are completely covered by a mucoperiosteal flap, which is deperiosteated. This moves the attached gingiva towards the top of the alveolar ridge and loses the interdental papillae. In addition, in the second act, it is necessary to perform an excision of the tissue above the cup and, possibly, perform a surgical correction of the soft tissue.

Four factors are considered important for immediate implant placement, aesthetics and soft tissue procedures:

(1) width and position of the attached gingiva

(2) the size of the alveolar process from the buccal side

(3) level and configuration of the gingival margin, i

(4) papilla size and shape.

These four factors are directly affected by the method of closing the extraction cup.

During installation, the method of aqueous tissue regeneration should be applied. Bone substitutes (Bio Oss, Interpor, etc.) fill the spaces between the walls of the alveolus and the implant or minor defects of the bone of the alveolus. It is covered with a resorptive membrane and sutures are placed. The main function of the membrane is to prevent bone resorption, thus achieving a much longer survival of the implant.

It is unfavorable for immediate implantation when the external or internal bone lamella is fractured during tooth extraction, or when there is greater dehiscence or fenestration of the alveolus. Depending on the size of the bone defect and the initial stability of the implant, installation should be delayed until the alveolus is completely reossified. The defect should be filled with bone substitutes and a membrane placed, thus creating very favorable conditions for later implantation.

Of the non-metallic implants, "tibigen", Biolox, Sandhaus are most often installed, and of the metal, one-phase, two-phase and one-phase-screw implants made of titanium.

The Tübingen implant is made of aluminum oxide-ceramic and is installed immediately after tooth extraction (immediate, immediate implant) or as a late one, when a bed is made in the bone. Their diameter is 4.5 and 6 mm and they have the shape of a cylinder.

These implants are especially used in children after traumatic tooth extraction.

After careful tooth extraction or tooth loss due to trauma, a surgical alveolus is formed with special drills and the implant is placed into it until complete primary stability. Implants are immobilized with a thin wire and surgical packing. The postoperative healing phase is usually pain-free and symptom-free. After three to six months, a definitive prosthetic work is made. The final success of these implants is not satisfactory, because the ankylotic connection of the bone and the implant compromises the implantation.

All two-phase implants can be installed immediately (Bronemark, IMTEZ, IMZ, Frialit, Ankvlos, Jota. Bone system, Core-Went, Dyna, as well as a number of other systems. This implies installation immediately after tooth extraction and complete covering with a flap of the implant (Rerhman plastic). ITI, Steri oss, Osseotite and some other implants do not require reoperation and are therefore considered single-phase implants, which is their undoubted advantage.

Two-phase titanium implants are installed using the already described immediate procedure.

However, single-phase screw-implants (Tramonte, bicortical, Kiss Bauer, Muraton) are installed using the immediate technique, with the fact that immediately after installation, a temporary or permanent metal-ceramic crown can be made.

Also in the healing phase, the patient, especially when it comes to the front teeth, can be made a temporary prosthesis or brace, taking care not to traumatize the soft tissues or implants. Dentures are lined with soft acrylate.

Recently, ITI-TE implants are used for early and delayed immediate implantation. ITI-TE is a solid, solid screw, with diameters of 4.8 and 6.5 mm and lengths of 8, 10, 12 and 14 mm. Their diameter in the apical part is 3.3 mm, 4.1 mm and 4.8 mm.

Many researchers and experts in the world and in our country are intensively working on immediate implantation. We will mention only some of them.

Block and Kent believe that immediate implantation has a number of advantages over late or delayed implantation. They state that with immediate implantation there is less trauma, the direction of the implant bed is better, which establishes better prosthetic rehabilitation, then, that bone loss is less, a longer implant can be implanted, and finally, by applying a membrane and a bone substitute, a greater width and height of the alveolar ridge is ensured.

And many other authors (Pecora, Lazzaro, Asman...) published a series of papers on immediate implantation. Some, working on a small series of patients, state that they had as much as a 94.1% success rate in a two-year follow-up. Many authors agree with these views, although there are also those who do not recommend their systems for immediate installation.

At the Institute for Oral Transplantation and Implantation of the Academy of Medical Sciences, as Assoc. Dr. S. Matić, from 1987 to 2000, 209 Đ.C.T. were implanted in 120 patients. endoral implants by the immediate or delayed immediate method. Implants are closed at our reception. The author states that 11.96% of the implants were explanted, in 39.26 the lifetime was longer than ten years, in 14.83% the implants lasted between five and ten years, and in 45.04% of the cases the lifetime was shorter than five years.

In personal communications with prof. Dr. M. Jurišić, and Assoc. Dr. A. Marković, confirmed a very high degree of success of immediate implantation (about 97%). They installed ITI implants (120 in total) in the area of the upper and lower front. During the observed time period of five years, three implants were explanted. Implant loss was due to trauma even though the prostheses were supported by soft acrylates. A number of patients were treated with bone substitutes and membranes for aqueous tissue regeneration. They have also installed 40 ITI-TE implants with complete success.

Finally, today in the world and in our country, immediate implantation is increasingly being introduced into practice. The basic raison d'être of its application is the fulfillment of the patient's physiological, functional and aesthetic requirements. So far, no valid studies have been published on success rates and differences between immediate and delayed implantation. Until this is done, there will be conflicting views, disagreements and disputes, but certainly many more advocates of this type of rehabilitation.

There are large individual differences - variations in the size and shape of the maxillary sinus. On inspection, the patient's wide face, short alveolar ridge and shallow palate indicate greater pneumatization of the upper jaw.

The bony walls of the maxillary sinus are covered with a mucous membrane one to two mm thick. It consists of three layers: ciliated ciliated epithelium, granular layer and modified periosteum. The membrane is not firmly attached to the bone, so it detaches easily. The intact membrane moves when the patient breathes, which is important knowledge when doing sinus lift surgery.

After the extraction of the lateral teeth in the upper jaw, due to bone atrophy, a smaller or larger pneumatization occurs, which can be seen on the orthopan image. Due to the early loss of the upper molars, a unilateral or bilateral edentulous saddle is a frequent indication for implantation. The height of the bone in such cases is often insufficient to perform endosseous implantation. The presence of bone mass is, as is known, the most important factor for the stabilization of all implant systems, and this is especially important in cases where the implant is installed in the lateral areas of the upper jaw. Several methods have been described that are used to compensate for lost bone height. Many techniques have been tried, that is, they are trying to change the anatomy of the sinus in order to increase the bone of the alveolar ridge. In this way, a sufficient number of implants of a satisfactory length could be installed. Many of these techniques require greater elevation of the sinus floor or alveolar ridge height, regardless of whether it is done in one or two stages. Free bone grafts or alloplastic materials were used for the primary stability of the implants, thereby changing the bone-maxillary sinus relationship.

Despite the application of a large number of methods for stimulating the sinus floor, they cannot yet be considered routine. Therefore, all methods should be checked on large series and in a longer observation period, in order to avoid any experimentation.

Recognizing these facts, Misch (1985) made a subantral classification of the bone of the upper jaw as: SA - 1: bone height 12 mm or slightly less between the sinus and the top of the alveolar ridge (the implant is placed in this case as standard);

SA - 2: bone height between 8 and 12 mm requires bone augmentation (Tatum osteotomy can also be performed here, depending on the assessment);

SA - 3: bone height of 5 to 8 mm between the floor of the sinus and the top of the alveolar ridge requires ridge augmentation and simultaneous implant placement, and

SA - 4: bone height of 0 to 5 mm between the floor of the sinus and the edge of the ridge requires a two-stage procedure. In the first phase, a sinus lift is performed and subantral bone augmentation is performed, and the implant is placed after 8 to 10 months.

The classification refers to the choice of an operative intervention, which can be single-phase (SA-2 and SA-3) and two-phase SA-4.

For a one-stage elevation of the sinus floor, the incision is made more palatally and extends sufficiently in the fornix. Relaxation incisions are made further apart to ensure a clear operative field. An opening is made on the lateral side of the sinus, a rectangular osteotomy with a diameter of 20 x 10 mm. It is important that the lower limit of the opening is about five millimeters from the top of the ridge at the place where the implant is planned. With a small round drill, the bone is cut mesially, distally and caudal, and the bone is perforated cranially in several places, taking care not to injure the mucous membrane of the sinus.

The broken bone is pushed towards the sinus and forms a new floor or its lower border. The mucous membrane is carefully separated from the bone, starting from the lowest part. It is easily detached, because it is weakly attached to the bone.

The minimum permitted bone height must be five millimeters. Bone density is also of particular importance, which should be at least D2 or D3.

When the membrane is pressed and the bone is moved inward and upward under the direct control of the eye, the implant is placed.

The implant must be stable. A bone substitute (Interpor, Bio Oss, HTR, etc.) is placed around the implant that protrudes into the sinus.

Alloplastic materials can be mixed with small pieces of bone taken from the chin or buccal part of the area of the lower molars, because in this way faster and better healing is ensured.

Some authors completely cut the lateral bony wall while the other part of the procedure is the same, with the fact that special care must be taken not to perforate the mucous membrane of the sinus during implant placement.

The preparatory procedure for a two-phase operation (SA-4) is the same as for a one-phase operation. This elevation of the sinus floor is performed when the bone height is 0-5 mm. A bone substitute is placed on the floor of the sinus and left for six to eight months. Here too, alloplastic material can be combined with crushed natural bone.

Many authors, Smiler and Holmes (1988), Prezmecky (1988), Bori (1991), have performed this operation on a large number of patients claiming to have achieved good results. Fight

(1991) modified the surgical procedure by taking a bone graft from the buccal part of the mandible, mixing it with bone substitutes and fixing it with a wire ligature. In this way, as he claims, he significantly shortened the healing time.

Complications during sinus lift surgery are primary implant instability (low alveolar crest height), swelling, pain, infection, sinus empyema and chronic sinusitis.

It goes without saying that before the operation, an x-ray of the paranasal cavities should be done and make sure that there are no pathological changes in the sinus. After six months, a reoperation is performed and an implant is installed.

When the atrophy of the alveolar ridge is advanced in the posterior parts of the lower jaw, lateralization or transposition of the n is recommended as an alternative for prosthetic rehabilitation. alveolaris inferior and implant placement. This procedure allows the installation of longer implants, which increases the percentage of success. The intervention is done when there is not enough ridge height to install an implant 10 or more millimeters long.

Lateralization of n. alveolaris inferiora involves opening the mandibular canal and moving the neurovascular bundle outward, buccally, in order to make a place for the implant in the bone, deeper towards the base of the mandible

An incision is made in the middle of the ridge or slightly lower, the mucoperiosteal flap is removed towards the base of the jaw and the chin opening is identified. The cortical and spongy part of the bone is removed from the opening towards the distal, identifies the neurovascular bundle and moves it outward as a whole. In this way, under the direct control of the eye, the implant bed is made in a standard way.

The surgical procedure always carries the risk that the patient will get temporary or permanent paresthesia (hypoesthesia, hyperesthesia, permanent anesthesia).

Despite the strong regenerative potential of peripheral nerves, sensitivity disorders can be both temporary and permanent. Most often, recovery of nerve function is expected in three to six months. Some authors, true to a small number of cases, state that after lateralization of the neurovascular bundle and implantation of implants, complete recovery of neurosensitive function can occur even after three years. They also state that in those patients, after the mentioned period, the subjective complaints are significantly reduced, but they remain permanently.

In the postoperative period, sensibility is monitored with various tests: sensitivity to touch, pressure, prick, cold, warm and, if there are teeth, by examining vitality.

A fracture of the mandible may occur during the operation, and the patient should be informed about this. A fracture of the jaw can be avoided by sacrificing less of the buccal part of the cortical bone and by avoiding a stronger directed force on the base of the jaw during the formation of the implant bed.

This procedure, similar to the sinus lift operation, requires a good training of the doctor and an extremely strong motivation of the patient. It is recommended that both procedures be performed in clinical conditions or in exceptionally equipped surgeries.

Indications for these operations are rare, so some dispute their rationality and justification. This is all the more so since no valid studies with larger series of patients have been published, from which one could safely conclude about the success of such interventions.

Complications may be due to poor pre-implantation preparation, poor treatment plan, wrong indication, incorrect surgical technique and inadequate preparation of the suprastructure.

Many authors tried to systematize complications, but the most acceptable would be the division into: Surgical complications and Prosthetic complications.

Surgical complications are divided into intraoperative and postoperative. They can be early (immediately during and after implantation) and late (after implantation).

Intraoperative complications are the following: bleeding, opening of the sinus or nasal cavity, nerve injury, injury to adjacent teeth, fracture of part of the alveolar ridge, jaw fracture, insufficient primary stability, implant fracture and instrument fracture.

Bleeding occurs if the incision is incorrectly planned from a. mentalis and from a. palatine major. It can also occur in the course of making a bed, especially in the upper jaw, and in the mterkanin simplex of the lower jaw from the spongy parts of the bones. Injury to the inferior alveolar artery or vein causes profuse bleeding. When possible, a shorter implant should be inserted to preserve the "safe zone".

Prophylactic bleeding from the spongy parts of the bone may occur during the production of the bed. Hemostasis is established with bed depth gauges and parallelism indicators.

Bleeding is stopped by tamponade and placement of the implant in the bed in the bone.

Blood vessels in the floor of the mouth a. submentalis, a. sublingualis and a. mylohyiodea can be injured during surgery for sialolithiasis, torus of the mandible, tooth extraction, iatrogenic injury, but as stated in the literature, also during implantation. Niamata et al (2001) reported a near-fatal airway obstruction due to bleeding and hematoma formation in the floor of the mouth that occurred after routine implant placement. Although implantation is a relatively simple procedure, the doctor must be prepared for possible complications, which should be promptly resolved.

The opening of the sinus and nasal cavity is a consequence of poor radiographic assessment when all standard clinical tests are most often positive. The lining of the sinus may be perforated or compressed. If this complication occurs, an X-ray should be taken and based on it, it can be decided to place a new, shorter implant. There are, on the other hand, opinions that in these cases implantation can be successful if the periosteum and mucous membrane of the sinuses are not injured. Bronemark (1984) and Feldman (1985) noted no significant sinus mucosal reactions, and no incidence of infection, even in cases of sinus perforation up to ten years old. Bronnemark also believes that when the bony floor of the sinus is injured and the mucous membrane is not perforated, when the implant lies under the periosteum, the created hematoma has the ability to form a callus. In this way, in his opinion, the bone mass above the body of the implant increases.

Scop et al. (1988) noted that of the third of negative implantation outcomes, the smallest number was caused by perforation of the floor of the maxillary sinus. Schroeder et al. (1991) believe that the maxillary sinus should not be injured during the preparation of the implant socket, as the development of infection can be expected. Finally, it could be concluded that if the nose blowing test is positive, implant installation is contraindicated. Therefore, it is extremely important to evaluate these relationships with pre-implantation radiography and not to attempt implantation.

Perforation of the nasal implant is a consequence of poor radiographic assessment. The assumption that the implant is in the nose is when strong resistance is encountered during installation and then it falls into the "empty". This is confirmed by examining the floor of the nose with a speculum. Infection may occur later. In these cases, explantation is necessary

Nerve injury is possible during the installation of endosseous implants (injury of the inferior alveolar nerve). Nerve injury, with clinical symptomatology, can be direct, or a hematoma is created or the implant is deeply placed. All of this can be avoided with correct pre-implantation diagnostics. If the mandibular nerve is ligated, the patient feels, regardless of good anesthesia, severe neuralgiform pain, which radiates mesial from the injury. After the anesthesia wears off, the patient may feel temporary or permanent anesthesia, paresthesia or hyperesthesia. The prognosis depends on whether there was only compression, a small lesion or a complete interruption of the nerve.

Rarely in these patients, if it is estimated that the injury is not major, the implant is returned by turning in the opposite direction, or raised above the canal and left for several months to ossify the roof of the canal. During the incision, n. mentalis and n. lingual. Identification of chin opening and protector for n. lingualis are a sure prevention of these complications.

Chorda tvmpani injury occurs when the bone in the back parts of the lower jaw is perforated during the making of the bed. The patient's taste for sweet, salty and sour is disturbed.

Knowing the anatomy and the various variations that result from bone resorption is very important, because nerve injuries can be avoided.

The blood vessels in the mandibular canal lie above the inferior alveolar nerve. It is therefore possible to avoid nerve injury, as bleeding is the earliest sign of canal injury suggesting that continued drilling may injure the mandibular nerve.

The therapy of these injuries is most often a symptomatic B vitamin complex, physical therapy, sedatives, etc.

Injury to an adjacent tooth especially occurs when an implant is placed where one tooth is missing. The injury can occur in the marginal part of the bone or in the middle or apical third of the root. The implant should be chosen so that there is a distance of 1.5 to 2, and at least 0.25 mm between the tooth and it. The injury is repaired by endodontic drainage of the tooth root canal or by explantation.

Fracture of part of the alveolar ridge occurs during installation. Namely, when the alveolar ridge is narrow, a fracture of part of the outer or inner cortex can occur. If there is a fear that it will sequester, the bone should be removed. During implantation, dehiscence and fenestration are not uncommon.

Dehescence is a defect of the cortical part of the alveolar ridge along the implant. It happens when the bone of the alveolar ridge is not wide enough, either due to the use of a wider drill or there is an error during the implantation itself.

Fenestration is most often an oval alveolar bone defect that exposes part of the implant. Both complications occur during installation, making the bed with drills of different diameters. Fenestration occurs if the axis of the bed preparation is not well directed towards the middle of the ridge, but the bur pierces the cortical bone, which especially happens in the upper jaw from the outside in the vestibule, and in the lower jaw in the sublingual fossa.

In the upper front, the axis of the drill must always be directed towards the oral side, because the natural tooth also had this direction.

The treatment is carried out using Bioss and a resorbable membrane based on the principle of aqueous tissue regeneration

A fractured jaw is a very rare complication. It happens when multiple implants are placed, especially in the lower jaw, and inappropriate force is applied. Depending on the case (open, closed fracture), one of the known methods of treating jaw fractures should be applied.

The primary stability of the implant is the guarantor of initially successful implantation.

A shallow and wide bed does not allow the primary stability of the implant. A shallow bed can be deepened and, if it is wide, you can try choosing a new implant with a wider diameter. This usually succeeds, so it is recommended to repeat the implantation after six to eight months.

Primary instability occurs when the implant is embedded in soft, poor quality bone. Instead of a drill, one of the self-tapping implants can be used.

Fracture of metal implants and instruments is extremely rare. Fractures occur much more often with ceramic implants. Usually, these are the consequences of errors during the manufacturing process, long-term use and many sterilizations of instruments. They must always be removed.

In the days immediately after implantation, edema, hematoma, bleeding and infection can occur, which are easily diagnosed and treated. Sometimes, in the early stages, the implant can be mobile, which is usually the result of poor surgical technique (overheating) or infection. In such cases, explantation is necessary.

Late complications of implantation are peri-implantitis, chronic sinusitis, chronic pain and implant fracture

Epithelial migration apical or so-called. intussusception with an inflammatory reaction is called periimplantitis. The European Association of Periodontics (1993) recommended a definition for mucositis and peri-implantitis.

Mucositis is an inflammatory process limited to peri-implant soft tissues, while peri-implantitis is progressive bone loss around the implant, associated with soft tissue inflammation.

The basic oenological factors of those complications, according to Newman and Fleming (1985), Rosenberg (1991) and Quirynan (1992), are bacterial infection or plaque theory and biomechanical occlusal load.

Etiological factors include incorrect surgical technique, early loading and especially the presence of bacteria, poor hygiene and occlusal traumatism of definitive prosthetic work. In other words, bacteria and implant load play a significant role in the etiology of peri-implantitis.

Anaerobic and facultatively anaerobic bacteria are always present in peri-implantitis with greater bone loss, i.e. greater depth of the pocket.

Salcetti et al. (1997) showed, in addition to the presence of gram-positive and anaerobic bacteria, a very high presence of prostaglandins and interleukins in peri-implants. They concluded that the number of bacteria was significantly correlated with the prostaglandin concentration on the side where the implants were lost compared to the control group.

Peri-implantitis begins with inflammation of the gingiva, which is red, enlarged, edematous or hypertrophic. Inflammation is similar to periodontal disease. The diagnosis is made on the basis of clinical and X-ray examination. Presence of inflammation, depth of the pocket, bleeding during probing, secretion, mobility, wobble of the implant are signs that indicate peri-implantitis.

Radiologically, bone loss is visible affecting the first third, half or the entire implant.

Epithelial migration apical, if left untreated, progresses, the gums bleed more, a pocket is formed, the implant wobbles and fistulas can appear. In our case report, in case of peri-implantitis, there were histological changes of the mucous membrane near the neck of the implant and the cystic sheath around the body of the implant. Changes in the gingiva are also characteristic, similar to periodontal disease. The squamous epithelium of the mucosa from the region of the neck of the implant was ulcerated, representing an open communication between the oral cavity and the body of the implant, which is explained by the presence of a large number of bacterial colonies. Gram-negative anaerobic flora is the most numerous. Under the influence of bacteria, that is, chronic inflammation, squamous-layered epithelium proliferates from the direction of the neck of the implant in the apical direction and forms the epithelial sheath of the body of the implant. The proliferated epithelium prevented the physiological healing of the implant by forming an infrabony pocket containing bacteria, cellular detritus, food debris, etc. The listed factors reflect chronic inflammation, which leads to the destruction of bone tissue around the implant.

The presence of active fibroblasts in the preparation shows that these cells preserved their reparative ability, but their function was compromised by chronic inflammation, which is why the implant was rejected.

In the analyzed cases of failure of sheet metal implants, between the body of the implant and the alveolar bone there is a sheath made of squamous epithelium and chronically inflamed connective tissue. The epithelium is localized next to the implant and has the morphological characteristics of the epithelium of the oral cavity mucosa, which indicates its origin.

Plaque control, elimination of pockets, replacement of lost bone with bone substitutes and application of resorbable and non-resorbable membranes is the main goal of treatment.

From the point of view of the treatment of peri-implantitis, a classification was made (Jovanović 1990, Spiekerman 1991).

The classification was made into four groups and their treatment is carried out as follows: Class 1, in which there is mucositis, horizontal and vertical bone loss, is treated conservatively, and if this fails, it is surgically excised, the implant is polished, the flap is shortened, thinner and placed more apically.

Class II is treated surgically, with the replacement of lost bone and provision of a zone of keratinized gingiva.

Class III in which the accumulation of plaque on the implant should be prevented by using diamond stones and polishing with erasers (Jovanović 1990). In addition, bone replacement should be performed.

Class IV in which, in addition to the basic processing and replacement of the lost bone, membranes are applied and the soft tissues are moved coronally to completely cover the membrane. The membrane should completely cover the bone defect around the implant.

In order to treat, the causes should be removed, inflammation and pockets should be eliminated, which significantly reduces the number of bacteria. After the incision along the crest, the mucoperiosteum is raised, possibly excision of excess soft tissue and curettage of the granulation tissue is carried out to the healthy, undamaged bone. The part of the implant outside the bone, especially the neck, should be processed with a turbine, diamond drills and then polished. The entire surface is washed under high pressure, a bone substitute (Bio Oss, Interpor, Biocoral, HTR, decalcified bone) is placed in the defect and covered with a resorbable or non-resorbable membrane (BioGuide, Gore Resolut, Ćore Tex, Millipore or a titanium membrane).

The wound is sutured with an extended or horizontal mattress suture, antibiotics are prescribed

and recommend rinsing the mouth with chlorhexidine. In this way, the intensity of inflammation is reduced and the number of bacteria is significantly reduced. If necessary, the occlusion should be repaired and the excised part of the implant repolished to prevent plaque accumulation.

However, this condition often ends in failure, with the extraction of the implant, which does not exclude attempts at healing if the implant is solid and part of the bone is preserved. In addition to inflammation and bone loss, damage to the n. alveolaris inferior.

Finally, if the implant wobbles, if there is an infection and noticeable bone loss, the explantation should be decided as soon as possible. Otherwise, there is even greater bone loss, so re-implantation on the residual alveolar ridge is increasingly difficult or impossible.

Chronic sinusitis can be a consequence of the presence of an implant in the sinus and constant irritation of the periosteum and mucous membrane. Diagnosis is simple and treatment includes explantation and probable Caldwell-Luc surgery.

Chronic pain in the lower jaw occurs when the implant is close to the mandibular canal, and not at a distance of one to two millimeters from its roof (safety zone).

Chronic pain in the upper jaw after implant placement is always a consequence of sinusitis.

Chronic pain that occurs if the implant is in direct contact with the nerve stem due to settlement or infection present in the bone. As a prevention of this complication, some authors recommend that the implant is not placed directly above the mandibular canal, but one to two millimeters above it.

Treatment of the complication is causal and most often requires removal of the implant

Fracture of the implant occurs after a poorly made superstructure, due to a failure in production or maltreatment of the implant (stress) during installation.

The fragment that is in the crown always comes out with it.

Many doctors are in a dilemma whether to remove or leave a well-fused implant in the bone. If the extraction, depending on the doctor's assessment, would be easy, then with a little sacrifice of the bone with the explantation instruments and the release of part of the bone, the fragment can be removed. However, a firmly fused implant with the bone is extremely difficult to remove. That is why many suggest leaving it, justifying it by the large loss of bone (often the entire bone around the implant has to be removed). This especially happens when the fracture of the implant is in the apical third.

Extraction of fractured implants can be done in several ways. There are special trepan-drills for explanting the rest of the implant, which frees the implant from the bone. They are applied when the alveolar ridge is of sufficient width. It is very rare that an explanted implant is replaced with another one with a wider diameter, because the ridge is so wide in rare cases. That is why it often happens that after six or eight months, a new implant is installed.

Obstructed parts of the implant can be removed by making a place in the bone from the mesial and distal side of the implant with fissured, thin drills and then removed from the socket with suitable instruments.

Immediately after surgery, dehiscence (repeat sutures), abscess (remove several sutures and drain), granulations (remove by curettage) and gingival hyperplasia may occur. The reasons for this are poor cooling, soft tissue trauma, infection and the formation of beds in the mobile mucosa. Also, the implant can split (overheating of the bone) and then explantation and curettage of the bed should be performed. After six months, reimplantation can be done. The bed can be filled with alloplastic material and covered with a resorptive membrane.

Prosthetic complications refer to the fracture of the fixation screw, the fracture of the full superstructure and the superstructure of retention systems and implants, bad prosthetic indications that are the result of bad manufacturing or bad occlusion and articulation, i.e. loading of the superstructure. All these fractures are solved individually from patient to patient.

The superstructure attached by the fixation screw can be loosened when the screw needs to be fixed or replaced. Fracture of the fixation screw rarely occurs. If a fracture does occur, a "slit" should be made in the rest of the screw with carborundum drills and an attempt should be made to remove it. If this fails, the entire construction needs to be redone.

Fracture of the full superstructure, the original stump, which is placed in the body of the implant, occurs very rarely. This is always a consequence of static errors during the planning of prosthetic work. It is extremely difficult and rare to remove the rest of the screw by making a slot in it or, if the fracture line is deeper, to cast a build-up and repair the work.

An overextended bar in the distal segment of the lower or upper jaw can fracture, requiring the creation of a new prosthetic work.

Fracture of the structure occurs extremely rarely and requires the construction of a new superstructure.

When the structural anchors are short, they can be uncemented, especially if zinc phosphate or polycarboxylate cement is used. Cementation of bridges whose anchors are implants - the implant should be done with polyacrylate cement and voice ionomer.

The importance of prosthetics, which some call implant prosthetics, is extremely great, because the understanding that implantation is only a surgical problem has been overcome. Since the beginning of the development of implantology, there have been prosthetic problems, and they are still present today, and according to some, even dominant. Due to inadequate load, traumatic occlusion, even an extremely well installed implant is rejected in a short time. On the other hand, the installed implant, the position of which is planned where satisfactory interjaw relations are ensured, the choice of material for prosthetic compensation, the method and time of loading the implant and the type of prosthetic work have a significant, perhaps even decisive, effect on the success of the implantation.

Many factors influence the success and effect of prosthetic therapy. Among them, the type of implant healing with living tissues, type, design and mechanical properties, transmission of occlusal forces, occlusion and articulation, gnathological and periodontological principles and the connection between the implant head and the superstructure should be highlighted.

The basic prosthetic principles of occlusion must be respected because, along with load control, they significantly affect the durability of the superstructure. A good intercuspidation is very important, which ensures the function of the chewing muscles and the temporomandibular joint. In other words, unlike natural dentition, embedded implants do not tolerate errors in occlusion and intercuspidation. Prosthetic therapy - proper loading, strength of force, direction and duration of force are extremely important for the durability of any type of implant, because there is no periodontal ligament around it as a shock absorber and load regulator.

Proper loading implies balanced occlusion and articulation, sufficient surface area of the tissue that accepts the load, and direction of forces in the axial direction of the superstructure support.

Implants can be unevenly, improperly loaded. This is especially the case when they are loaded early, when there is poor occlusion and articulation, when the stumps of the installed implants are divergent, when their arrangement is unsatisfactory and when the mechanical properties of the superstructure are poor. Depending on the method of prosthetic treatment, masticatory forces can be transmitted either through the implant alone, or through the implant and natural teeth, or through the implant and residual alveolar ridges.

The load distribution depends on the location, number and spacing between the implants. Implants suffer the greatest pressure in the area of the first premolar and the first molar, and a larger number of brackets redistributes the forces better (one bracket-one member).

The distribution of forces over the implant depends on the material, size and shape of the implant, then on the size of the bone-implant contact surface, the width of the residual ridge and the quality of the bone structure.

Parallelism, tete-a-tete bite, cusps of appropriate size, form and axial loading are important for prosthetic work.

In fact, implants in the mouth are constantly under the influence of forces of different directions and strength, which causes less or more stress.

The head of the implant corresponds to the ground stump of a natural tooth. During the eventual grinding of the implant with a turbo machine, the gingiva must not be injured. The head of the implant may only be ground minimally in the mouth with ample, additional cooling.

It is important to preoperatively determine the place, the position on the alveolar ridge, where the implant will be installed. The position of the coronal part of the implant in the dental arch, its orovestibular and mesio-distal slope, as well as the gingivo-occlusal height should, as much as possible, correspond to the position of the lost tooth, the slope and the gingivo-occlusal height that its crown would have after grinding. This practically means that the coromar part of the implant should have a slope that coincides with the slope of the remaining teeth in the arch. In addition, it must be placed in the part of the edentulous ridge where the lost tooth was located in infraocclusion 1.5-2 mm.

When one tooth in a row is missing, intraoperatively it is not difficult to determine the place of the implant according to the adjacent teeth, while taking into account the central occlusion.

The problem is presented by patients who are missing a large number of teeth and the remaining teeth do not provide fixation of the mandible in the position of central occlusion.

In those cases, cast fixed templates made of transparent acrylate are used during the act of installing the implant and are aligned with the marked places on the model. The patient wears the templates in his mouth until the temporary or definitive prosthetic work is made.

The suprastructure-implant-bone system is exposed in the mouth to forces of different degrees, directions and duration, so it is extremely important to correctly direct and redistribute these forces.

Correct occlusion and articulation when it comes to implants as supports, whether in fixed or mobile prosthetics, is the most important factor in their value and durability.

Finally, it should be pointed out that a particularly significant problem in prosthetics is the implantological solution of complete toothlessness in the lower and upper jaw. To this end, many authors have proposed a significant number of solutions. Thus, Spiekerman (1990, 1991 and 1993) proposed four different concepts for the solution of toothless lower and upper jaw: 1. Installation of two implants in the interforarninal space connected by a round or oval factory step. It is recommended for patients with a small or pronounced ridge whose bone height must be 10 mm. 2. Installation of 3-5 implants connected by a step, applying them to atrophic ridges, thus putting a load on both the implants and the residual ridge. 3. Installation of 4-6 implants connected by a step and distally added cast extension. Indications are strong atrophy of the ridge on top of which is n. alveolaris inferior or mental canal. Retention is ensured by the use of adhesives and magnets, and the prosthesis is held only on the implants. 4. Installation of 4-6 implants in the intermental space. Distal extension must be done and the prosthesis is fixed to the implants with screws. From time to time only the doctor removes the prosthesis.

Concepts 1 and 2 can also be applied to the bones in the upper jaw. Also concepts 3 and 4 can be done in the maxilla if the floor of the sinus is raised beforehand. It is understood that in patients in whom six implants have been installed, one can also think about making a fixed work if the quality, height and width of the alveolar ridge are satisfactory.

Metals, acrylate and ceramics are used as superstructure materials.

There is disagreement among authors about when to do the superstructure. Some are for making provisional, temporary work immediately after installation but without articulation, while others suggest that such constructions should not be made at all. They base their position on the fact that it is better to provide some time for the healing and consolidation of soft and bone tissue and then temporarily or definitively load the implants. Definitive prosthetic work is suggested for fabrication after a few months. It could be said that it is advocated by a large number of implatologists, although there are also those who immediately do definitive prosthetic work, considering that it is a great advantage of implatology.

However, experience seems to show that it is better to wait a few weeks before making definitive work excluding systems where osseointegration is expected.

A temporary bridge or crown immediately after flap suture is cemented in such a way that a piece of rubber from a glove or rubber band is placed over the head of the implant to prevent the penetration of cement into the tissue through the incision.

After the installation of two-phase implants, it is often the practice of the doctor and the request of the patient to keep the old ones or make new temporary prostheses. In this way, the patient, while the implant rests in the bone, has the function of speech, aesthetics and, to some extent, the function of chewing. In such cases, it is very important to ensure that the implant does not suffer the slightest trauma during speech, swallowing and chewing movements. It is necessary to remove enough acrylate from the inside of the prosthesis where the implant is located, perform complete decompression and, possibly, perform soft lining of the prosthesis. During the entire healing period, it is necessary to constantly monitor the patient. It should be noted here that after installation, the implants are exposed to the effect of horizontal forces of the muscles of the tongue, cheeks and lips, so the superstructure should be done as soon as possible. Implantation can be successful or unsuccessful. The success of implantation is defined by the duration of the installed implant. If the implant performs its function for five years, the implantation is considered successful, with the condition that no significant bone defect remains after the removal of the implant. The success of implantation depends on many factors: tissue quality, type of material, implant design, type of healing, degree of occlusal stress, possible corrosion and a number of other factors.

Implantation failure implies removal of the implant. The percentage of failure increases with age. Failure rates are higher in the upper jaw than in the lower jaw.

There are early and late implantation failures. Early failure is due to wrong indication, poor surgical technique and early loading of the implant. Late failures occur after a poorly done superstructure. According to the duration of the implant, the following age groups are accepted: from 1-5, from 6-10, from 11-15 and from 16-20 years.

Success and failure should be distinguished from survival, which refers to implants that remain functional even for many years. Implantation success and failure rates have been addressed by many researchers. However, in the literature there is a small number of valid works from which one could conclude about the successes of individual implantation systems and the results that would cover a longer period of time.

In order to standardize the evaluation of implantation success, certain criteria have been defined that are primarily related to the wobble of the implant and the formation of pockets.

For these reasons, at the Harvard Conference on Development, in 1978, an attempt was made to uniformly evaluate the success of implantation for a period of five years.

The success of implants was discussed at the conference, but the expected results were not obtained due to insufficiently researched literature and the application of implant systems that have not been scientifically tested.

Then the proposal (Schnitman and Shulman) about the success of the implantation was accepted, which contained the following parameters: • that the mobility of the implant in all directions is less than one millimeter; • that radiologically no soft tissue is observed around the implant; • that bone loss does not exceed 1/3 of the height of the implant; • that gum inflammation, if present, responds to treatment; • that there are no signs of infection or injury to adjacent teeth, paresthesia, anesthesia and injury to the mandibular canal, sinus and nasal cavity.

The conclusion of the Harvard conference is that the implant must provide function for five years in at least 75% of cases.

Already in 1982, at the Conference in Toronto, Albrektsson and colleagues proposed stricter criteria in view of Bronnemark's findings on osseointegration.

It was then concluded that the biocompatibility of the material, the macroscopic and microscopic nature of the material surface, the condition of the implant bed, the surgical technique ("healing" phases) and the preparation of the superstructure are of great importance for the success of the implantation.

Albrektsson, Zarb, Warthington and Eriksson (1986) made a proposal on the evaluation of the success of individual implant systems and concluded: • that the implant must be completely immobile; • that the x-ray image does not show illumination, that is, the peri-implant connective tissue; • that bone loss per year is less than 0.2 mm and that there is a success rate of 85% after a five-year period and 80% at the end of a ten-year observation period.

These criteria were adopted as a minimum in evaluating the success of the use of individual implantation systems.

They have provided ratings for a range of systems in use based on performance monitoring. In doing so, the observed systems were evaluated on the basis of materials, scientific research, indications, installation techniques, complications and published results. Although some of their conclusions should be taken with a grain of salt, we highlight them here as a possible way to evaluate implant success.

They conclude that subperiosteal implants are "unpromising and a thing of the past"; crystalline carbon implants "do not have a satisfactory outcome in clinical research"; then, "that the outcome of leaf implants is unsatisfactory"; monocrystalline sapphire implants "are not for routine clinical use," Tübingenski "does not offer longer-term studies than 100 implanted implants." They conclude similarly for IMZ, i.e. that "success cannot now be determined with certainty" and for the transmandibular plate implant (Mandibular staple bone implants) they consider that "they are within the accepted standards", that the Corevent system "can be considered experimental", etc. This is how they conclude about some other systems, with the exception of Bronnemark's system, which they claim "is the best studied so far and has the most acceptable criteria", criticizing its "limited use" due to the price.

However, regardless of these conclusions, it should be emphasized that many of the analyzed systems have been confirmed in long-term clinical practice.

On the other hand, Fallschlussel (1986) cites the statistical, clinical results of other researchers and claims that transdental implants are "very successful" (over 90%), that the success rate for leaf implants after five years is 90%, after six years 78%, after seven years 70%, while for screw-implants he states a success rate of 63% after four years, 50% after seven years up to 93.7%.

According to him, during seven years of observation, the symptomatology of failure is as follows: implant looseness, pocket formation, pocket infection, pressure pain, horizontal bone breakdown, osteitis, sensitivity disorders, exposed parts of the implant and sinusitis.

He concludes that it is most urgent that in the final conclusion, in five or ten years, clinical success can be evaluated based on a number of parameters such as the gingival bleeding index, pockets, implant mobility index, plaque and calculus index, radiographic index, patient satisfaction, etc. The mentioned parameters can be quantified and the obtained results show the success or failure of the implantation.

In June 1988, well-known researchers and practitioners in the field of implantology met in Bethesda, organized by the National Institutes of Health (NIH) and the National Institute of Dental Research (NIDR). They also provided criteria for the successful implantation of systems that were in use until then.

In the ten years since the first conference on oral implants, a lot has been done in terms of developing better materials and newer techniques that have led to improved implant-bone contact. A large number of endoseal, subperiosteal and transdental implants remained in operation for more than ten years. Indications and contraindications for different types of implants are described. The complexity of the surgical, prosthetic and periodontal procedures, which are used in order to install and maintain the implant more successfully, have shown that a multidisciplinary approach is necessary.

Long-term studies that competitively compare different types of implants are needed to provide information that will be something more than a mere assessment of success. The functional success of various implants should include such criteria as the possibility of wearing a prosthetic replacement without discomfort, satisfactory aesthetics, clinical and X-ray evidence that the tissues are healthy. The proposal to establish a National Registry was made with the aim of collecting data and documentation on the various procedures used in the United States of America. Future research on materials and techniques is also suggested.

Finally, it is most urgent that in concluding five or ten years, clinical success can be assessed uniformly, based on a series of adopted parameters that can be quantified, which facilitates the assessment.

Based on the analysis of larger series of known implant systems, it was noted that implants are often applied in an uncontrolled manner. At the same time, the lack of valid documentation can be noticed, especially when considering the criterion of the success of the applied procedure. To evaluate the effectiveness, a prospective study is proposed for a period of three years, with at least 100 patients who are monitored for two years, which would ensure a five-year clinical follow-up of the results. This is especially true of new implant systems, which should not be approved for use without strict evaluation criteria. When evaluating the results, a distinction should also be made between the success rate and the implant survival rate.

Albreksston and Sennerbv (1993) presented interesting conclusions about certain systems, which could be summarized as follows: - subperiosteal implants are not for routine use; - for the Tübingen implant, there are no valid data on the ten-year follow-up of the results, and they are used, above all, for the replacement of individual teeth, which is in contrast to other implantation systems; - IMZ has no documented success rates, and the claims of 97.85% success refer to implant survival; - data on ITI implants are the best documented, but since there are several designs, the degree of success is also different; - The Bronnemark implant is still the best controlled oral implant, both from an experimental and a clinical point of view, with a success rate of 85-100% in the upper jaw and 93-99% in the lower jaw.

In the conclusion of their considerations, the mentioned authors point out that subperiosteal, transmandibular, Listasti (Linkow), Tübingen, ITI, IMZ and Bronnemark implants give quite acceptable five-year results. However, in terms of ten-year results, which is considered the most appropriate time period for evaluation, the data on most of the mentioned systems are unacceptably scarce, so their evaluation is impossible. It should be borne in mind that the five-year success rate is often nothing more than the survival rate for 0-5 years. Based on that, it was concluded that the current practice of "experiments on humans" should be stopped when it comes to implants.

This indicates the obligation of all those involved in implantology to evaluate their results on a larger number of cases, after ten or more years, using standard mind criteria and evaluation parameters.

The difference in conclusions lies in the criteria that were adopted first at the Harvard Conference, then in Toronto and Bethesda, and refer to achievements up to 1986, so it should be expected that the results could be different even today.

So far, in small series, and with a short observation time, both much better and much worse implantation successes have been achieved. However, it can be said that among implantologists there is a lot of disagreement about success and failure, which indicates that there are still not enough valid clinical and statistical results for the systems that are in use. All this indicates that it is the obligation of implantologists to work even harder and on a greater number of cases, and to announce their results of success or failure for a period of ten years or more.

The incorporation of alloplastic materials into the living tissues of the upper and lower jaw represents a certain form of violation of the patient's physical and mental integrity. Various and unexpected complications can occur during implantation, as well as in the postoperative period. Therefore, the problem of dental liability is extremely sensitive and complex. The dentist's responsibility can be moral, misdemeanor, disciplinary and criminal.

Criminal responsibility aims to ensure the correct performance of the act of implantation, which must be performed according to all the principles of modern science and practice, that is, dental doctrine. If the doctor does not adhere to these principles, the act of implantation can be considered an act of medical malpractice.

If, however, a professional error is made that is treated as negligent treatment, only the court is competent to assess material compensation to the patient based on the criminal law. Before the court, the medical association should try to make an out-of-court settlement. In such cases, the Medical Chamber can decide whether to revoke the license to work from a doctor who has made such a serious professional mistake.

There is a legal formulation of "generally negligent conduct" by doctors in diagnosis, treatment or rehabilitation. The negligent act of treatment also includes the "deterioration of the patient's health condition", which is not excluded either during or after implantation.

It is known that during or after surgical interventions, transient bacteremia can occur, which causes recurrence or the appearance of bacterial endocarditis.

Heart diseases, especially congenital heart defects such as interventricular septum defect, valve, atrial septum defect, pulmonalis artery anomaly, require preventive antibiotic protection of the patient before implantation.

The American Association of Cardiology (ANA) recommends preventive, increased administration of antibiotics per os in one session, considering that this is the most effective way to prevent the consequences of transient bacteremia.

If the recommendations of this association are not followed in such patients and there are consequences for the patient's health, the doctor who performed the implantation can be accused of negligent treatment.

There are also a number of other diseases that require pre-implantation preparation in the same way as is done for other orthopedic surgery interventions.

Poorly performed pre-implantation preparation in terms of assessment, diagnosis and conditions for implantation can also be qualified as negligent treatment and subject to liability. This would primarily refer to injuries to the maxillary sinus, when an infection occurs, or injuries to the mandibular canal, when temporary or permanent paresthesia occurs, as a result of implant placement. It is understood that in such cases the court should also ask the expert team, which consists of established experts in this field, the court of honor of the SLĐ, the medical chambers of 1 professional associations that deal with these problems.

The patient's consent to implantation aims to protect the dentist from liability, that is, the consent is the basis for justifying the medical operation, but on the condition that it was performed according to the rules of dental practice and science. In other words, the patient's consent does not absolve the dentist from responsibility if such consequences occur that are related to negligent treatment and work outside the principles established by dental practice and science.

That is why it is very important to keep detailed documentation of all diagnostic and therapeutic procedures applied to patients before, during and after implantation. This is very important, because the assessment of a possible professional error is made on the basis of medical documentation and not on the basis of subjective opinion.

By giving consent, the patient is not aware of all the risks to which he is exposed. But the doctor must inform him about it. It is understood that "detailing" is not necessary here in the sense of predicting all risks, but only those that are possible in the doctor's opinion during implantation. In other words, the risks should not be presented in detail and medically accurately. A notification in "main outlines", presenting the "general picture of the specific risk" in a way that is understandable to the medical layman, is sufficient. The doctor performing the implantation is "expected" to inform the patient only about the risks that, according to medical knowledge, actually exist, not about the risks whose existence cannot be ruled out, but for which there is no positive scientific evidence.

However, it happens that the patient is unsatisfied with the health service, for example with the aesthetic appearance of the performed superstructure, and demands payment of damages, considering that the doctor made a professional mistake. From such misunderstandings arose the need to form the Yugoslav Association for Medical Law (JUMP), which, for its part, offered a code of medical ethics. It suggests that there is a close connection between medicine and law. In the West, dissatisfied patients go to court immediately and demand financial compensation. Of course, if it is proven that the doctor made a professional mistake, he has to pay a very high compensation. Unfortunately, this practice has not yet taken root in our country. But if obvious professional mistakes have been made, patients can seek justice from the court through forensic medical expertise. A very important role should be played by the medical chamber, which regulates the basic rules of professional work and the obligations of doctors towards patients.

On the other hand, the voluntary agreement between the patient and the doctor has a binding character, because in this way unnecessary legal and professional conflicts are avoided. At the same time, one must not make a mistake about the standards of the profession, science, that is, the adopted doctrine, which otherwise implies not only a class and moral but also a legal obligation. Finally, it can be concluded that every implantation must be done in accordance with medical deontology.

Implantology as a scientific discipline has, without a doubt, a future. 1 it is a future that put down its roots in the world a little earlier than we accepted it. The possibility of applying the scientific achievements of implantology so far and the practical methods it finds and develops are great. That is why the chances for adoption and improvement of the methods of its further application are indisputably certain and undoubted.

Modern implantology, with its theoretical and practical results, its methods and achievements, is becoming an inevitable factor in maintaining the health of modern man.

What implantology offers is an implant, that is, a new or new teeth. And "new teeth" are not only a new look, a new smile, but also new health and a completely different quality of life. The aim of the implantologist is to constantly research, doubt, search and find new ways and methods of implantation, because her current achievements are not final, perfect and definitive. It is certain that in parallel with the development of scientific and theoretical thought in the field of implantology and the improvement of scientific methods of applying its results, new materials will inevitably and continuously be sought and found to be used in implantation. Just as the "silver-gold" era was replaced by unknown materials, so the application of titanium, tantalum and chromium-cobalt-molybdenum alloys will give way to some new elements or alloys that will be used to make implants and replace damaged bone tissue of the jaws.

Implantology as a science and implantation as a method, which immediately emerges from it, in the time to come has extraordinary chances and wide possibilities for affirmation, development and verification of the results it will achieve.

It is certain that people engaged in scientific research work in the field of implantology will spare no effort to find new materials for implantation and new methods and methods of installation in order to, first of all, extend the time of "survival in place" of the implant. This implies that certain modern implants which are considered the most successful and which, based on numerous researches, when installed by experienced clinicians, are mostly kept in the place of implantation for about ten years, in the future they are replaced by implants of a more perfect and permanent type. The perspective is in searching and finding new materials from which implants would be made, as well as in the search for a method of implantation that would ensure its durability. This would result in an implant that would be a long-term and stable solution, a solution "for life". It seems that this would also be the most likely way to overcome the handicaps related to the lack of natural teeth.

Further scientific breakthroughs in the installation of two-phase implants are extremely important for the development of this very successful method. The importance of perfecting this implant form stems from the results shown so far and the fact that the remodeled bone accepts them satisfactorily after several months of rest in the bed. The fact that their temporal and functional success is already measured for decades and that bone loss of 0.1 mm per year indicates that this method of implantation, by investing great scientific research efforts, has the best chance of becoming a model for the XXI century. If, during the scientific research work, a more perfect and better method and form of implantation is found, which should not be ruled out, the method of delayed implant installation will certainly be improved. The method of rehabilitation, through the immediate installation of implants, will be the subject of serious scientific research.

The perspective is to review empirical experiences for the purpose of improving immediate implantation and significantly increasing the survival "in place" of the achieved implantations. This method of implantation deserves special scientific, professional and practical efforts to be perfected, first of all, due to the fact that the patient receives new, implanted teeth immediately after the extraction of the natural ones.

Previous research and application results show that the "epithelial junction" is the weakest point of the implant, its weak point. That is why one of the basic directions of research in implantology and the improvement of implantation methods will be focused on the relationship and realization of a greater fusion of implants and soft tissue and the establishment of a stronger connection between the implant and the bone tissue of the jaw. Therefore, the goal is to improve the existing ones and find new methods and materials that will be used in implantation, which would achieve an epithelial attachment of the implant close to or identical to that of a natural tooth.

In this regard, it seems to be a very realistic expectation that in the not too distant future, through the processes of application of interdisciplinary and intradisciplinary exchange of scientific data and knowledge from implantology and other sciences, their application and further methodological improvement in practice, the aggressive endoseal method will be replaced by a simple, non-aggressive method for creating beds.

Along with the aspiration for improvement and application of non-aggressive methods in the field of implantology, a series of theses can be presented in support of expectations about the special place and importance of the role that the application of lasers and laser technologies will have and play in that process.

The subject of special interest of researchers must be focused on finding implantation methods that would speed up the healing process and ensure more successful union of the implant with the soft and bone tissue of the jaw. It should be expected that new, more perfect and more suitable materials, elements or alloys of elements that modern science is constantly searching for will play their role in this as well, which would replace or supplement the current use of titanium, tantalum or chromium-cobalt-molybdenum alloys.

On the other hand, although, according to the exact indicators of scientific studies, they give satisfactory results in terms of preserving the jaw bone, it is reasonable to assume that the same or similar fate will be experienced by the materials and substances used today as bone substitutes. Therefore, it is almost certain that scientific research in materials, medicine, dentistry and other sciences will aim at finding such materials whose substance will be able to adequately replace natural human bone, which will be well tolerated by the human body, i.e. in which implants will be able to be installed immediately. It is certain that the materials used today as a replacement for the jawbone will be, in the near future, an outdated and outdated scientific solution. They will most likely be replaced by more perfect materials made according to new formulas and new technologies, which, according to the method of installation and use, will enable good tolerance and permanent acceptance and integration of the implant into the surrounding bone tissue.

The results of scientific and technological research on finding and applying new materials, where only some of them will be alloplastic, will certainly create the possibility of making such an artificial bone into which, already during its production or immediately after its installation, fixed and stabilized implants would be fixed.

Undoubtedly, the expected application of this type of new materials would find its role in increasing the height and width of the bone of the alveolar ridge, which would enable the installation of implants and the production of functional total prostheses.

Under the conditions of application of existing knowledge, achievements and experiences, a much stronger and more reliable connection of the bridge on the supports was achieved on the "implant-implant" segment than on the "implant-tooth" segment. From the point of view of today's scientific knowledge, this is completely expected and understandable, because the natural tooth, thanks to the peridontium, is extremely stable during the act of chewing itself, subject to minimal movements, where, according to the "natural determination" itself, it absorbs the forces of chewing without harmful effects on the natural tooth itself.

In contrast, the implant is osseointegrated, rather brittle, practically solid and almost immovable, which, from the point of view of comparison with the previously mentioned functions and characteristics of the natural tooth, can have an exceptional impact on the final success of the implantation. In addition to the possibility of making two-part implants whose supragingival part would have the function, conditionally speaking, of a shock absorber that would imitate the periodontium of a natural tooth, the possible solution could be the discovery and application of such materials or substances that will stimulate the organism and that will not only be compatible, but also interactive. This would imply that the bone and the implant would not stand passively, as two opposed objects in the relationship between the living and inanimate part of nature, that is, in the relationship between natural matter and artificially created things, but as the relationship of two bodies joined into one compact whole of a functional character within which they will stimulate each other in order to realize their function and the role they should have. The vision of the future development of implantology will not exclude the finding and production of materials that will enable, with the appropriate new methodology, the damaged bone tissue of the jaw to be replaced without applying radical surgical procedures. In other words, the substance for bone tissue replacement would be directly located or perhaps injected at the site of the damaged part of the bone, in the alveolus or in the bed of the future implant. The characteristics of those materials should be such that, immediately after placement, they turn into a mass of high degree of hardness and resistance, similar to that of natural bone.

In the near future, the role of implants will have a very important place and will find the widest application in constructive dentistry. This presupposes that scientific interests in the search for a more perfect and new one must also be directed to the field of surgical implantation as well as the creation of superstructures, bridges on implants. Although even today the surgical installation and production of suprastructures on implants is practically very effective and relatively easy to perform, it is certain that the curiosity of scientific research must be focused on finding even simpler and easier methods of their installation and production.

Finding cheaper, but extremely high-quality biomechanical abrasive materials, which would be used for the manufacture of implants and superstructures, would affect both the price and the significantly wider application of implantation in the future. Reducing the share of the cost of the labor invested in making implants would also affect that the benefits and achievements of implantology are not the privilege of a narrow class of people.

Many issues in the field of prosthetics require further and deeper analysis and solutions and the acquisition of new practical experiences. Those that are set as primary and that require solutions in the near future refer, first of all, to biomechanical load, design and material for the superstructure.

The application of new and more perfect solutions in implantology will also help with complications. It is reasonable to expect that possible complications will be minimized and the number of cases almost negligible. At the same time, their possible treatment will be easier, better and more efficient.

We are convinced that the rapid development of information and computer technologies will also affect oral implantology. It is not difficult to imagine that implants in the future will contain sensors and chips that will allow the dentist to obtain important measurement data from the implant, such as, for example. ph values, physical forces and stresses and the like, which is necessary in the process of good maintenance of already installed implants. Miniaturization and falling prices of measurement sensors and chips make this perspective quite possible.

By introducing it into dentistry, implantology, as a scientific discipline, has the advantage that, as a relatively young field of science and the application of its achievements in practice, it can use all the experiences and advantages of the global information exchange system.

Continuous and complete insight into all information and achievements, experiences and results of scientific research in the field of implantology is ensured through the most modern electronic systems of the world network of global communications, such as the Internet today. The computerized system of holding, storing, using and exchanging information will contribute to the application of the most proven, most reliable and best systems and achievements in the world in the process of practical implementation of implantation. Connecting institutions and individuals through global communication networks in the world will exchange data and research experiences, and by monitoring the success of implants, the results of the application of scientific research in practice will be appreciated. This will enable the best and most proven implantation system to be applied to each patient, which will contribute to the best results in terms of implant success.

Educational and scientific programs of university education must build such an approach in the field of theoretical and practical application of research results in implantology, which will ensure the process of permanent education of dental students. Through the appropriate fund of theoretical and practical classes, students, during their regular studies, and especially dentists who are already in the process of work, would be trained for routine implantation.

It must be borne in mind that implantology has its own scientific foundations. It can, must and should be classified where it belongs, in the structure of medical and dental sciences, scientific disciplines and areas, because its indisputable scientific foundation gives it that right.

Any different approach to implantology, say, as a routine activity, a skill, and even as an art within the dental profession represents a movement in the wrong direction.

Implantology and the implant are a chance for modern dental science to show what it can do today, at this level of its development, but also an opportunity to recognize, encourage and support the chances and possibilities of future scientific research and development in the field of implantology.

The future of implantology is not unrealistic fantasy games, that is, baseless thinking or intellectual speculation with unrealistic goals. Because implantology is already today a real world of acquired scientific knowledge and experiences and their practical application in the process of preserving human health. However, implantology is, above all, the future. A future of great opportunities, but also chances that, I believe, will not be missed.

The use of implants in modern fixed prosthetic practice has become a reality. This was made possible by numerous experimental and clinical researches that, in recent decades, have been carried out by a constellation of scientists of various profiles. The results of these researches provided the profession with relevant information about the properties of materials suitable for incorporation into the human body, the so-called biomaterials from which implants are made, their design and dimensioning, the mechanisms by which bone and gingiva are attached to them, as well as their ability to withstand loads involved in oral functions.

Today, it is known for sure that pure rhitane and titanium alloys are the materials from the group of metals that human tissues clean best. From non-metals, these are hydroxyapatite and ceramics. The basic principles that guide the doctor when he determines the indication for the use of implants, when he chooses implants, when he plans compensation and realizes certain stages in this complex therapeutic process are defined. Of course, the appropriate instruments and equipment needed to work in the patient's mouth and in the dental laboratory have been perfected.

Since in economically developed countries this expensive discipline has taken root in routine dental practice, the acquisition of basic knowledge in this field must, today, be an integral part of the professional education of our students. This should enable them to more easily follow the literature and professional development in the field of oral implantology, so that in future practice they will be able to make a positive selection when determining the indication for implant installation, choosing an implant and planning a replacement.

Two types of implants are important for fixed prosthetics:

1. Transdental implants i

2. Endoosseous implants.

This group of implants includes stakes that are inserted transradicularly into the part of the bone above or below the root annex with the aim of anchoring the destabilized tooth in the bone.

They were introduced by the Strock brothers (1943), using tantalum pins. Since then, numerous variants of transdental implants have been applied, with more or less success.

Modern implantology has at its disposal factory-made posts that can be made of titanium, titanium alloys, aluminum oxide ceramics or a combination of these materials. They have a standard length (3.5-4 cm), while their thickness varies from 0.9 to 2.5 mm. The transdental stabilizer must be rigid. Therefore, its diameter must not be less than 0.9 mm. Rigidity will certainly be greater if a thicker post is used, but it can only be used if it is estimated that the remaining thickness of the root canal walls will be satisfactory and that there is no risk of cracking or perforation. The length of the stake that can and should be implanted is determined intraoperatively, and after implantation, the excess in the coronary part is cut and removed.

Today, the following variants of transdental implants are used:

- conical pins made of unpolished titanium,

- screw-shaped titanium stakes,

- tri-lock posts, also made of titanium, in which only the apical and lateral parts are in the form of a screw, and the intraradicular part has flat surfaces, - posts made of monocrystalline ceramics, namely no. 1 which is conical with a flat surface structure and no. two which is in the form of a screw.

The implant is placed in the part of the bone above the apex in the direction of the axial axis of the tooth and in the entire length of the root canal so that it more or less protrudes into the coronary part. That is why we are talking about three parts of the implant: - intraosseous, which integrates with the bone tissue above or below the apex of the root, - transradicular, which is attached to the walls of the root canal with dental cements (for this purpose, polycarboxylate cements are used, and the binder is applied only on the pre-marked part of the stake that is placed in the root canal), - coronary, which protrudes into the crown part of the tooth. After placing stakes i cement bonding, the excess length of the coronal part of the post is cut so that it is level with the occlusal surface of the tooth, and then the filling is placed. The remaining intracoronary part of the stake serves to improve the retention of the filling. In screw-shaped implants, threads are used for this purpose. If conical implants with a flat surface are used, this can be roughened with a thin grinding instrument. The filling should be composite to avoid the risk of eventual ionization and metal corrosion.

Installation of transdental implants is performed in one surgical act. When a tooth with a healthy pulp needs to be stabilized with a transdental implant, excision of the pulp and expansion of the root canal are performed in the same visit as the surgical act of installing the implant. When the dental pulp is diseased and infected, the surgical act of implantation must be preceded by visits during which the root canal will be cleaned, expanded and sterilized using endodontic methods.

A tooth is considered to be stable if its movements in the bony alveolus (intrusion and orovestibular tilting) under the influence of forces current during oral functions do not exceed the limits of its individual physiological mobility.

Stability is a prerequisite for survival in the jaws and functional efficiency of the teeth.

If there is an increase in the length of the extra-alveolar part, and a decrease in the length of the intra-alveolar part, or a combination thereof, destabilization of the teeth in the alveolus occurs, which is manifested by different degrees of loosening, that is, pathological tooth mobility under the influence of physiological forces.

The described condition may be a consequence of:

- advanced horizontal resorption of alveolar bone due to periodontopathy,

- anomalies of tooth root growth and development,

- external root resorption,

- surgical removal of the apical third of the root due to a cyst or periapical process,

- fractures or fauste rout in the apical or middle third of the root,

- deep substantial tooth fractures, after which insufficient root length is left behind,

- root dissections and hemisections,

- tooth extrusions in the absence of antagonists.

The strand of transdental implants, whose intraosseous part plays the role of ankylotic apical extension of the tooth root, corrects the painless ratio of the length of the crown to the length of the root, establishes the biomechanical suitability of the tooth and stabilizes it in the bone.

Thanks to this, teeth or just the roots of teeth that would otherwise be condemned to extraction, can remain in the jaws for many years and be used as carriers of crowns and bridges, or participate in the support of numerous variants of partially worn partial dentures.

Whether and to what extent it will be possible to lengthen the root with the implant and correct the ratio of the length of the crown to the length of the root to the biomechanically optimal one depends on the length of the intraosseous part of the implant. This, on the other hand, depends on the amount of bone available for implantation. It is considered that there should be about 10 mm of bone immediately above or below the root apex, in the direction of the axial axis of the tooth. That is why the assessment of the amount of available bone for implantation is one of the important factors of prognostically reliable implantation planning.

Research on the healing process and the structure of peri-implant tissues shows that the biological basis of integration is the same as in endosseous implants. Fibroosseous bonding or osseointegration may occur. Successful implantation involves osseointegration, which forms a rigid ankylosing connection between the implant and the bone. Factors that have been proven to be intraoperatively or postoperatively responsible for unsuccessful endosseous implantation can also jeopardize the osseointegration of transdental implants.

However, an important difference between transdental and endosseous implants is that transdental implants are completely enclosed in the bone and are classified into groups called closed systems similar to implants used in orthopedic surgery. Therefore, they are not exposed to direct or indirect influences from the content of saliva, gingival fluid and substances that are taken into the mouth.

In contrast to this, endosseous implants are open systems since one part of them passes through the soft tissue covering of the jaws and protrudes into the oral cavity. The peri-implant supporting tissue can react to a chemical and bacterial attack by saliva and gingival fluid components with inflammation that quickly leads to peri-implantitis and apical migration of the gingival epithelium.

The percentage of successful transdental implants is high and can be compared to the percentage of successful conventional endodontic procedures or apicotomy. This enviable percentage of successful implantations is related to the fact that closed transdental implants are not threatened by peri-implantitis and apical migration of the gingival epithelium. Since the implant is placed transradicularly, its position and direction are defined by the natural position of the teeth in a row, which minimizes problems related to the unfavorable inclination and localization of current in endosseous implants, which can compromise implantation.

However, in patients in whom oral hygiene is not at the required level, inflammation of the marginal gingiva, bone resorption, apical migration of attachment epithelium with the formation of periodontal pockets and root caries can be expected. These processes, destroying the residual part of the tooth and its protective tissues, lead to a situation when a perfectly integrated implant must be explanted. That is why adequate oral hygiene is the first and absolute prerequisite for implantation.

The indications for tooth stabilization using transdental implants are numerous and are explained in the publications of the authors of our School. Transdental implantation is only partly a measure in the service of prosthetics, that is, a measure that can improve dental prosthetics therapy in a certain area of indication.

If there are conditions for implantation, transdental implants can be used to stabilize upper and lower teeth, single-rooted and multi-rooted. In multi-rooted teeth, one implant can be placed through each canal. If the conditions for this do not exist, one canal will be used to place the implant, while the others will be filled with conventional canal filling. At the end of the healing period, if necessary, an artificial crown (faceted, ceramic or metal-ceramic) will be made on the stabilized tooth as a single, aesthetic restoration, dedicated restoration or bridge anchor.

At the end of the healing period, a planned compensation is made. As previously mentioned, it can be an artificial crown, faceted, ceramic or metal-ceramic, as an individual aesthetic restoration, a dedicated restoration or a bridge anchor.

Tooth preparation, impression procedure, registration of interjaw relationships, entering the model into the articulator, the process of creating a restoration in the dental laboratory, as well as the principles on which the balancing of the occlusion is based, do not differ from the procedures applied in conventional stomatoprosthetic practice.

If the crown of the tooth is destroyed, which is why its augmentation must be done, the part of the post that protrudes coronally can be used for the retention of the composite restoration. In that case, additional paracanal retention stakes must be used.

The demarcation of the preparation should be located in the tooth tissue below the level of the surface where the composite build-up adheres to the coronal surface of the root. Thanks to this location of the demarcation, the crown will surround part of the root under the abutment in the form of a ring, which will contribute to its mechanical strengthening.

Endoosseous implants are installed in the bone of the residual ridge, in order to act as substitutes for lost teeth as a support for fixed or mobile restorations, or as supports for the retention system of mobile prostheses. They are produced using industrially appropriate technology. The condition for their use is that the patient has sufficient height, width and length of the bone of the residual ridge, as well as that the structure, that is, the density of the bone, is satisfactory. When conditions exist, they can be installed in the front or side of the upper or lower jaw.

Today, the profession has at its disposal a large number of endosseous implants, which, depending on the manufacturer, differ in design, method of installation and methodology of making the restorations they will wear.

The creation of restorations on endosseous implants goes beyond the scope of conventional prosthetics, and in addition to the adequate equipment of the office and the dental laboratory, it requires more than the usual professional skills of doctors and dental technicians.

Only a doctor who knows well the doctrine of conventional dental prosthetics and the specific characteristics of endosseous implants can base the indication for their installation in a specific patient on realistic and prognostically reliable grounds. A good plan is a basic prerequisite for the success of the therapy. The surgical technique of installation is undeniably important, but only when a good operative technique consistently follows the therapy plan conceived by the prosthetist. While conceiving the therapy plan, the prosthetist must have a complete vision of the future compensation, which, depending on the specific anatomical conditions and economic status of the patients, is the most favorable possible solution for him.

Each endosseous implant consists of three basic parts. They are:

- intraosseous, the part or body of the implant inserted into the bone of the residual ridge by a surgical procedure, - the intraoral part that protrudes into the oral cavity and to which the compensation will be attached, which is called the implant carrier, and - the transmucosal part or the neck of the implant that connects the intraosseous with the intraoral part. The boundary between the implant support and the transmucosal part marks the location of the gingival margin of the crown and can be compared to the demarcation of the preparation on the natural supports of fixed restorations.

The body of the implant can be made of commercially pure titanium, titanium alloys, plasma-treated titanium, or titanium coated with hydroxyapatite.

According to the shape of the body, endosseous implants are divided into:

- plate or leafy and

- implants whose body imitates the tooth root.

Leaf implants are designed to use the available length and height of the residual ridge for installation. They are flat and thin in orovestibular diameter. Their thickness is about 2.5 mm. They usually have the shape of a rectangle whose length is from 15 to 30 mm and height from 8 to 15 mm. Perforations are an integral part of their design, which, thanks to bone ingrowth, mechanically reinforce their fixation.

Implants whose body imitates the root of the tooth are designed so that the available height and width of the residual ridge are used for installation. Their diameter is from 3 to 5 mm and their length is from 7 to 20 mm. They can be smooth, threaded, perforated, hollow, solid, rough or coated with bioactive material. There are two basic forms: a) cylindrical ones that are pressed into the surgically formed bone bed under pressure and their surface is characterized by microscopically visible roughness and b) implants that have macroscopically visible threads and are pressed into the bone bed by screwing and thereby achieve initial fixation in the bone. Most often

they make cylinder and screw combinations

The advantages of implants in the form of tooth roots, compared to leaf-shaped ones, are the following: - they can be installed in different parts of the residual ridge; - the center of gravity of the implant in the bone can be precisely formed surgically; - the bone defect after eventual explantation of the implant is similar to the defect that remains after the extraction of a natural tooth.

That is why implants whose body imitates the shape of the tooth root are the most used today. Data from the literature show that a large percentage of successful oral rehabilitation can be achieved using this type of implant. Noting this, we do not deny the use of leaf implants, which remain the forms of choice for a certain area of indications.

The fixation of the implant body in the bone is of critical importance for the success of the implantation. Only an implant that is rigidly attached to the bone can serve as a support for a crown or bridge.

According to Carl Misch, rigid fixation rx>includes a state when the implant shows no signs of vertical or horizontal mobility exposed to forces of 0.01 to 5 N. A rigidly fixed implant can accept functional loads and properly distribute them to the bone.

After surgical implantation, during the healing period, fibroosseous binding of the bone to the implant or osseointegration, i.e. biointegration, may occur.

Fibroosseous bonding implies the presence of a peri-implant membrane made of healthy dense collagen tissue in the space between the implant and the bone. Some qualify this membrane as a false periodontium. Its thickness can be from 5 µm to 250 µm.

Histological studies indicate a functional arrangement of fibers parallel to the longitudinal axis of the implant body. Although the peri-implant membrane can achieve a type of adhesive connection with the surface of the implant, it cannot be functionally compared to the periodontium in natural dentition. The peri-implant connective tissue membrane enables displacement of the implant in the bone center of gravity during functional loads, and the biological significance of this displacement cannot be identified with the significance of the physiological mobility of the teeth. The mobility of the implant in the bone bed reduces its ability to accept and properly distribute functional loads on the bone.

Osseointegration represents direct contact and close adherence of the bone tissue to the surface of the implant without the interposition of non-osseous connective tissue. Schroeder called this phenomenon functional ankylosis. Depending on the material from which the implant is made, osseointegration can be:

- mechanical and

- bioactive.

Mechanical osseointegration is based on the presence of undermining such as recesses, grooves, threads, perforations and similar forms on the surface of the implant. As the bone grows into these irregularities, a mechanical entrapment effect occurs. In doing so, no chemical bonding occurs. It is realized in implant systems made of biomertic materials, such as titanium, plasma titanium or titanium alloys. The bioinertness of titanium is the result of the fact that it is a reactive metal and therefore an oxide layer is spontaneously formed on its surface when it is in contact with air, water or some electrolyte. This qualifies as surface passivation. Titanium dioxide is the hardest material in the mineral world, and as a dense layer it protects the metal from chemical attacks, including those from tight liquids. The oxide layer is completely insoluble in contact with the tissue and does not allow metal ions that could react with organic molecules. Brannemark believes that if there is no oxide layer, the contact of metal and tissue would lead to a corrosion process.

The microcrack between the surface of the implant and the bone of the order of 100 A to 200 A, which cannot be observed under the magnification of a light microscope, is filled by a layer of titanium dioxide.

Bioactive osseointegration is achieved with systems in which the body of the implant is made of or coated with a bioactive material such as hydroxyapatite or bioglass. The bioactive material binds to the bone through the physical-chemical interaction of bone collagen and hydroxyapatite crystals. This connection is similar to ankylosis in natural dentition.

According to Đranemark and colleagues, only osseointegration ensures rigid fixation of the implant in the bone, which is why they consider it the basis for successful implantation. Apart from the materials from which the implants are made, an important prerequisite for osseointegration is that the endosseous part of the implant is closed and unloaded during the healing period in the so-called afunctional state. The healing period or initial phase of implant acceptance lasts three months in the lower jaw, six to nine months in the upper jaw, which depends on the bone structure.

During the healing period, new bone or callus is formed that bridges the crack between the implant and the bone. In fact, the primary callus is already formed during the first month and a half, but since it then has little resistance to loads, the implant must still remain out of order. The primary callus is filled with well-distributed dense bony trabeculae and it reaches maximum resistance to loads after four and a half months. The bony junction reaches the maximum compactness of the structure on average one year after the installation of the implant.

In this regard, it is necessary to point out the factors that can make osseointegration difficult or impossible. These are: - overheating of the bone during the surgical formation of the implant bed. Bone resorption occurs if it is exposed to temperatures higher than 47°C; - non-adjustment of the surgically formed bed to the dimensions of the implant body; - excessive pressure during implant placement;

- apical migration of the gingival epithelium i

- premature exposure of the implant to functional loads, before the end of the implant acceptance period.

The second stage of the so-called mind. remodeling of the peri-implant bone bed lasts three to eighteen months and begins after exposing the implant as a carrier of compensation to functional loads. This stage is also called the consolidation stage, and it depends on the extent to which the functional loads and the resistance of the peri-implant bone tissue are mutually balanced.

It should be noted that osseointegration is not achieved on the entire surface of the implant. Namely, one part of the surface makes direct contact with the bone tissue, while in other parts, a connective tissue membrane is interposed in the microspace between the implant and the bone. It is considered that for the successful functioning of the implant, it is sufficient to achieve osseointegration on 25% to 75% of its surface.

In clinical practice, the quality of the connection between the implant and the bone is evaluated based on:

- implant mobility under the effect of vertical and horizontal pressure;

- percussive sound that is clear and ringing with a quality connection

- X-ray.

The transmucosal part or neck of the implant is located between its intraosseous and intraoral parts. It passes through a surgically formed opening in the mucoperiosteum. Placed in close contact with the tissue layers that make up the mucosa of the residual ridge, the epithelium and the fibers of the subepithelial connective tissue, the implant neck plays a significant role in the establishment of the gmgivo-implant attachment, which closes the communication between the oral cavity and the peri-implant bone tissue. This closure prevents the penetration of infection from the oral cavity towards the implant bed in the bone. The initial healing and formation of the gingivoimplant closure takes about two weeks, but the level and contour of the gingival implant gingival collar is definitely stabilized after 4 to 6 weeks.

Closing takes place in three levels:

a) the level of the peri-implant sulcus,

b) level of implant epithelial attachment i

c) the level of adhesion of the connective fibers of the gingiva to the surface of the implant neck.

Closure at the level of the peri-implant sulcus is based on a close fit

epithelium of the free gingiva next to the surface of the implant neck. The potential sulcus space is constantly perfused with a capillary layer of gingival fluid, which, thanks to its constituents, plays the role of glue that stimulates this connection. The contact strength is variable and subject to changes related to the turgor of connective tissue fibers, the health of the free gingiva, and changes in the amount and composition of gingival fluid, which can be influenced by many endogenous and exogenous factors.

If inflammation of the free gingiva occurs, the edematous and red one has a tendency to bend and separate it from the surface against which it is pressed. The potential peri-implant sulcus space is transformed into an actual space and closure at this level is absent. The average depth of the peri-implant sulcus is about 3.5 mm.

The second level of closure is the implant-epithelial attachment, which is morphologically and histochemically very similar to the epithelial attachment in natural dentition. Namely, the cells of the gingival epithelium do not directly touch the surface of the implant neck, but between them there is an interposed adhesive organic layer called the epithelial attachment lamina. The epithelial attachment lamina is thought to actually be a product of epithelial cells. In addition to the epithelial attachment lamina at the level of the implant-epithelial junction, hemidesmosomes were also observed, highly differentiated cellular structures that are considered to play the role of mediators in the realization of dentoepithelial attachment in natural dentition.

There is a lot of evidence for the existence of an implant-epithelial attachment. So, for example, if real or colloidal solutions are initiated into the peri-implant sulcus, they remain at its bottom without penetrating deeper tissues. When an implant is explanted, an adherent layer of connective epithelial cells that has separated from its connective tissue base is usually left behind at its neck.

The characteristics of the implant-epithelial attachment depend on the material from which the implant is made. Surface tension and surface structure, i.e. the degree of polish of the implant neck surface, are of particular importance. The best adhesion is achieved with the surface of polished titanium. Plasmized titanium is less suitable, which is related to the higher surface roughness.

The third level of closure is below the implant-epithelial attachment and is achieved by the connective fibers of the free gingiva. Dense bundles of interlaced fibers are observed, which in the form of a fibrous ring surround the neck of the implant and ensure close adhesion with their turgor.

The length and shape of the transmucosal part of the implant can be different. The length is from 2 to 10 mm, and the shape can be cylindrical or inverted conical.

This part is always made of polished titanium.

The described gingivo-implant closure represents a barrier for the penetration of infection from the oral cavity towards the peri-implant bone tissue. The prognosis and durability of the implant in function largely depend on the effectiveness of this barrier.

According to one classification, endosseous implants are divided into:

- one-piece implants and

- segmented or multi-part implant systems.

The first group includes implants whose body, neck and support are made of one part, and their body can be in the shape of a tooth root or leaf-shaped.

They are implanted in one surgical act. Immediately after installation, the implant carrier, in the form of an overgrown tooth, protrudes into the oral cavity, which is why it is exposed to loads induced by the musculature of the lips, cheeks and tongue during the entire healing period. Their application is relatively simple from the prosthetic point of view. The equipment, instrumentation and process of making fixed restorations are, with minor deviations, basically the same as in conventional prosthetic practice.

The fact that during the entire healing period the implants are exposed to loads, instead of osseointegration, fibroosseous bonding is achieved for the most part. Difficult or impossible osseointegration makes the application of one-piece implants risky and prognostically uncertain.

Segmented implants are complex systems whose body, neck and support are made as separate parts.

By segmenting, it is possible to install the body of the implant, and in some systems both the body and the neck, and to keep the implanted part of the implant closed and unburdened during the healing period. In this way, the most important condition for osseointegration is ensured, which is the reduction of the load on the implant during the healing period. After the healing period, all parts of the system are interconnected.

The surgical procedure of installation is described in the appropriate textbooks. The prosthetist should know that the installation can be performed in one or two surgical acts, which depends on the design of the implant system used.

Systems manufactured in such a way that the body and neck of the implant are included in the composition of one part imply installation in one surgical act. The implant is installed so that the part that protrudes above the surface of the cortical part of the bone passes through the surgically formed opening of the soft tissue cover of the bone and ends at the level of the outer surface of the mucous membrane. The interior of the embedded part is closed with a hygienic cap to prevent the deposition of calculus, the ingress of detritus and the growth of the surrounding gingiva.

Successful implantation after the end of the healing period results in the osseointegration of the implant body and the formation of the implant-epithelial closure. Then the hygienic cap is removed from the implant in order to fix the implant support. After that, the preparation of the corresponding supplement is started.

The second group of segmented implants is produced so that the body of the implant is one part, and the neck and the implant support are the other part of the system.

This group of implant systems involves surgical installation in two acts. In the first procedure, a bed is surgically formed in the bone of the residual ridge in order to accommodate the body of the implant up to the level of the cortical part of the bone. The interior of the implant is closed with a hygienic cap and this is covered with a mucous membrane.

After the healing period, a second surgical procedure is performed during which the mucous membrane is lifted to expose the hygienic cap, which is removed and the body of the implant is connected to the transmucosal healing cap. It has the shape of an implant neck, and remains in the mouth for two weeks to six months. It can be made of polymethyl methacrylate or titanium. If it is a question of restorations on implants in parts of the dental arch that are not of particular importance from an aesthetic point of view, prosthetic interventions can begin two weeks after the completion of the second surgical procedure, since this is the period during which the implant-epithelial closure is established. The height and contour of the free edge of the pari-implant gingival tissue are not particularly significant, since it does not matter where the border between the implant carrier and the implant neck will be, that is, the edge of the future crown in relation to the free edge of the gingiva. The neck of the implant can protrude more or less into the oral cavity, and the crown ends supragingivally. From a hygienic point of view, this relationship is considered favorable because it facilitates cleaning. The healing cap is removed and the implant support is fixed to the body, after which the appropriate restoration is made.

However, if it is a question of restorations on implants in parts of the dental arch where aesthetic requirements are a priority, the border between the implant support and the neck of the implant where the edge of the future crown will be located should be located subgingivally. Such relations can only be achieved if, after definitive stabilization of the height and contour of the free edge of the peri-implant gingival collar, an implant support is selected whose transmucosal part is 0.5 to 1 mm lower than the actual height of the peri-implant gingival collar. Then the border of the implant carrier and the transmucosal part, i.e. the edge of the future crown, will be located 0.5 to 1 mm subgingivally. Therefore, the transmucosal healing cap remains in the mouth for 4 to 6 weeks, as long as it is necessary to definitively stabilize the height and contour of the peri-implant gingival collar. Then the transmucosal healing cap is removed, a suitable implant carrier is selected and fixed to the implant body. After that, the preparation of the appropriate compensation is started. The edge of the crown on the implant will be lowered subgingivally.

The forerunner of all segmented osseointegration implant systems is the Branemark system with a body that resembles the root of a tooth. Later, other similar systems were developed, the most famous of which are Core-Vent, IMZ and ITI.

The enviable percentage of success achieved by the application of segmented osseointegration systems, primarily those whose body is in the shape of a tooth root, has meant that they are today treated as a realistic alternative for the oral rehabilitation of edentulous or edentulous patients.

The original Linkow leaf implants are designed as one-piece. A significant percentage of failures is related to the inability to avoid loading the implant during the healing period. That is why today they are also made as segmented systems, which provides one of the conditions for osseointegration.

Segmented implant systems, in addition to the described basic parts, also include appropriate parts for their interconnection, as well as instrumentation adapted to a precisely defined methodology for installing the implant and creating the compensation it will carry.

The implant support is the part that protrudes into the oral cavity and to which the appropriate compensation will be attached. Depending on how they are attached to the body of the implant, supports are divided into three groups. These are: - supports that are attached with a screw when the walls of the cavity in the body of the implant are formed by a suitable line, - supports that are attached by means of a binding material - cement, when the walls of the cavity in the body of the implant are flat, possibly roughened and

- supports that are attached to the body of the implant by friction.

The second division is based on the relationship between the longitudinal axis of the implant support and the longitudinal axis of the implant body. If the longitudinal axis of the support follows the longitudinal axis of the implant body, we are talking about straight, and if it overlaps a smaller or larger angle, we are talking about inclined implant supports. The inclination of the implant support in relation to the axial axis of the body in the orovestibular or mesiodistal direction must not be greater than 30°.

The third division is based on the way the crown or bridge is attached to the implant support. There are basically two methods of attachment, namely: a) attachment using dental cements when we are talking about fixed crowns and bridges on implants and b) attachment using fixation screws when we are talking about conditionally mobile crowns and bridges on implants.

Conditionally, the patient cannot take off and put on the mobile braces, but only the doctor does it during mandatory and regular patient check-ups.

Since these loads to which the restoration is exposed during oral functions are transferred to implants and peri-implant supporting tissues, fixed and conditionally mobile crowns and bridges qualify as implant-supported restorations.

The supports to which the crowns or bridges are attached with dental cements are full and in their shape resemble dental crowns prepared to accept fixed restorations. They can also have transverse grooves on the outer surface as additional retentive forms.

The supports to which the crowns or bridges are attached are hollow with screws, and the walls of the cavity are formed by a suitable vine for the fixation screw. Their outer surfaces are flat and smooth.

Making restorations with endosseous implants is, today, an alternative for the oral rehabilitation of edentulous and edentulous patients. Broadly speaking, four possibilities can be considered.

Replacement of one tooth with an implant-supported crown.

Missing one tooth, in a person with an overall healthy dentition who has an excellent prognosis, is usually the result of a congenital anomaly (anodontia), or tooth loss due to trauma or extraction after failed endodontic therapy. A tooth may be missing in the mtercanine or transcanine region.

For this category of patients, the creation of an implant-supported crown is a superior therapy compared to the creation of a bridge, which is the best possible conventional prosthetic solution. The medical, ethical and economic justification of implantation is based on the following facts: - Using an implanted carrier avoids extensive grinding of two healthy, intact teeth and reduces the risk that during this procedure the health of the pulp and periodontium will be endangered, especially in young people. - Better aesthetic effects can be achieved with an implant-worn crown than the effects that can be achieved with a bridge. This statement is especially true for people who are missing a tooth in the visible part of the row, and their natural teeth are small and short, or separated by diastemas, or their smile line is high. With an implant-worn crown, the shape and position of the natural tooth can be copied to the maximum, as well as its relationship with the neighboring teeth and the free gingival margin. - A properly shaped and dimensioned crown on the implant provides more favorable conditions for maintaining oral hygiene than a conventional bridge.

Oral rehabilitation of patients with a shortened dental row.

Conventional stomatoprosthetic therapy of patients with unilaterally or bilaterally shortened dental row implies, in the best case, the creation of mixed mobile partial prostheses. Provided that optimal oral hygiene is observed and that the condition and prognosis of the remaining teeth are good, the installation of endosseous implants enables the construction of bridges. The functional, prophylactic, aesthetic and psychosocial advantages of conventional bridges compared to mobile partial dentures are well known.

They can be reduced to the following statements:

1. Physiological, dental load transfer.

2. The functional efficiency is almost the same as the efficiency of natural teeth.

3. Phonation is not disturbed because the compensation is limited to the space that was filled by natural teeth. Therefore, the conditions for phonation are similar to the conditions with natural teeth. 4. Preserved sense of taste, touch and heat of food thanks to uncovered oral mucosa.

5. Quick adaptation of patients to compensation.

6. Extraordinary aesthetic effects, especially when metalwork is used as a building material.

7. Protection of the oral mucosa and alveolar bone.

8. Positive psychosocial effects due to the feeling of security that the patient has with a well-fixed restoration whose presence in his mouth is not noticed by the environment. For people from certain professions (singers, actors, announcers) this aspect is particularly important.

All of the above also applies to bridges on implants. However, the logical question arises as to whether it is functionally possible to identify a bridge on implant abutments with a bridge that has natural teeth for supports. Namely, in bridges that have natural teeth as supports, the damping effect of the periodontal ligament plays an important role in the distribution of load on the surrounding bone. Proprioceptors in the periodontium and appropriate reflex pathways direct the chewing process, which is why the functional efficiency of bridges is almost the same as the efficiency of molar teeth.

Implanted bridge supports do not have a periodontal ligament, but are rigidly attached and directly transfer functional loads to the peri-implant bone support. The knowledge gained during many years of experimental and clinical research indicates that an implant-supported bridge can be functionally identified with a bridge that has natural teeth for supports. Namely, implants are functional equivalents of natural teeth, both in terms of the masticatory forces they can withstand and in terms of the subjective feeling of patients during oral functions. Patients feel implants as substitutes for natural teeth.

Oral rehabilitation of patients with broken teeth.

There is no doubt that for people with broken teeth, a fixed bridge is the replacement of choice. An interrupted tooth row, when the residual ridge is limited on both sides by teeth capable of bearing additional loads, proportional to the number of lost teeth and their position in the row, is a general formulation that defines the indications for the construction of conventional bridges.

That is why, in patients in whom, based on the number of lost teeth and their position in a row, it is estimated that the loads will exceed the resistance of the potential supports due to the large span of the bridge, the construction of the bridge is abandoned and some variants of mobile prostheses are planned. By installing one or more implanted supports, a bridge can be made in these categories of patients.

Oral rehabilitation of edentulous patients.

Oral rehabilitation of edentulous patients requires solving numerous problems related to retention, stabilization, functional efficiency of the restoration, and its prophylactic effect. A conventional prosthetic solution, a mobile total prosthesis, even when, thanks to favorable anatomical conditions, as well as the skill of the doctor and dental technician, it is perfectly made, can only be qualified as a necessary evil. There are many reasons for this:

1. A total prosthesis unphysiologically stresses the tissues of the residual ridge.

2. The process of bone resorption caused by tooth loss, although somewhat calmed down, continues.

3. The compensation covers a large part of the mucous membrane and, preventing the perception of stimuli, reduces the sense of taste, touch and heat of food, and can adversely affect the patient's speech. 4. The masticatory efficiency of the total prosthesis is significantly lower compared to the natural dentition.

5. The patient's adaptation to the supplement is slow.

6. After a certain period of use, the total prosthesis must be repaired by lining and occlusal balancing.

7. Risk of fracture.

8. Unfavorable psychosocial effects due to the patient's insecurity and fear that the prosthesis may fall out of his mouth.

To all this should be added the problems related to the retention and stabilization of total prostheses, especially the lower ones, in patients in whom the anatomical or psychological conditions for retention and acceptance of compensation are unfavorable. Despite the knowledge, skill and effort put in by both the doctor and the dental technician, the final outcome can be failure for the doctor and dissatisfaction for the patient.

The installation of endosseous implants in edentulous patients, in which there are favorable anatomical conditions, enables the creation of an implant-supported bridge. In this way, the previously mentioned shortcomings of the mobile total prosthesis are eliminated, that is, a more favorable type of oral rehabilitation of patients is carried out.

Endoosseous implantation is even more important in patients in whom the conditions for retention and stabilization of the prosthesis are unfavorable. Endoosseous implantation enables, and depending on the anatomical conditions, i.e. the number of implanted implants, the oral rehabilitation of edentulous patients with mixed wear excellent retained and stabilized mobile total dentures with a reduced plate, or in the most difficult cases, the production of mobile total excellent retained prostheses with a maximally extended plate.

Which option will be chosen depends on the anatomical conditions, real needs and economic status of the patient.

Industrially produced parts of segmented implants are placed on the market together with a set of auxiliary tools and devices required for installation, for interconnecting parts of the implant, for making and fixing the compensation.

Less experienced doctors may be confused by the number of these parts. All the more so, as devices with the same purpose are often called by different names.

This part will show the basic elements that make up the set, the most common names, purpose and way of using them. The design and materials from which they are made are very similar regardless of the manufacturer. Therefore, one set can usually be used for segmented implants from different manufacturers.

Closing cap or hygienic cap - is placed after the first surgical act to close the cavity in the body of the implant and prevent the ingress of detritus, the deposition of calculus as well as the ingrowth of the surrounding gingival tissue. It is usually a screw whose head covers the entire surface of the implant body. There are also caps that are fixed to the body of the implant thanks to the friction between the pin and the cavity in the body of the implant. The screw head is thin and usually has the same diameter as the implant body. This makes suturing the soft tissue easier. In the second surgical act, the cap is removed to place the second component of the implant system.

In some systems, the diameter of the screw head is larger than the diameter of the implant body. This prevents the bone from growing over the coronary edge of the implant body, which can make it difficult to place the implant carrier later.

It should always be carefully checked that the screw is well placed and tightened so that there is no crack between the coronal surface of the implant body and the screw head. If a crack remains, the bone grows into that space, which makes it difficult to remove the screw in the second act. Then the coronary surface of the implant body can be damaged, which would make it impossible to precisely place the second component of the system.

Healing cap - it is a screw with a cylindrical head 2 to 10 mm high that is part of some implant systems. When the screw is fixed to the body of the implant, its cylindrical head passes transmucosally and more or less protrudes into the oral cavity. The healing cap remains in the mouth for 2 to 6 weeks, during which period the peri-implant gingival tissue heals. Then it is removed in order to place a suitable implant support and proceed with the fabrication of the restoration. Healing caps are made of synthetic resins, titanium, titanium alloys, or gold alloys. They are used with implant systems whose installation is performed in two surgical acts.

Transducers are devices used for precise intraoral registration of the position of the implant body in the bone and the implant supports in the patient's mouth during the impression procedure. Thanks to this, it is possible to enter into the working model the analog of the implant body and implant supports. There are two types namely:

a) gears that are fixed to the body of the implant i

b) gears that are fixed to the body of the implant and to the implant carrier.

Laboratory analogues are copies of the body cavity of the implant and the implant carrier

made of aluminum or brass. They are installed in the working model using a transmission.

Cuffs and stakes for modeling - Cuffs for modeling are caps that are fixed with screws to laboratory analogues of implant supports on the model and serve as a basis for the further process of creating a replacement, and are part of its metal skeleton. They can be made of plastic or precious alloy from which the replacement is made. The role of the plastic cuff in the process of making the crown can be compared to the role of the external foil adapter in conventional fixed prosthetics. They are produced in several lengths. They can be shortened and thus adapted to the dimensions of the support.

The application of industrially produced caps ensures flawless adaptation of the inner surface of the crown to the outer surface of the implant support. The modeling stakes are used to form a cavity in the compensation for access to the fixation screws.

Fixation screws are a mandatory component of implant systems designed to accept conditionally mobile restorations. They are made of titanium, titanium alloys or gold alloys. They are fixed using a titanium universal key. They can be very long when they run the entire length of the central part of the crown and the implant support. Their head is located on the occlusal surface of the crown.

The second type are short screws whose head ends on the coronary surface of the implant support. Therefore, a cavity must be formed in the crown for access to the screw. After fixation, the surface of the screw head is covered with a layer of resilient material such as gutta-percha, silicone or cotton, over which a composite filling is placed in the cavity of the crown.

The prognosis of natural teeth - carriers of crowns and bridges depends on the extent to which they are threatened by carious destruction, destruction of supporting tissues and resorption of alveolar bone. Dental implants cannot be destroyed by caries, but the peri-implant bone tissue is susceptible to destruction, which results in the loss of its fixation in the bone. The initiators of resorption of peri-implant bone tissue are, as in natural dentition:

a) inflammation or

b) traumatic occlusion.

The pathogenesis of inflammation-induced resorption is very similar to the pathogenesis

periodontal disease in natural dentition. The main etiological factor is plaque accumulated in the region of the implant neck, from which microbial products attack the peri-implant gingival tissue, causing its inflammation. This spreads towards the implant bed, causing apical migration of the gingival epithelium and bone resorption. The expansion of the inglamation and the apical migration of the epithelium are much easier and faster than in natural dentition, which is a consequence of the delicate gingivoimplant closure. That is why optimal oral hygiene, as a critical factor for preserving the health of the peri-implant gingival tissue, is the first absolute prerequisite for the durability and functional efficiency of the implant and the replacement it carries. In a relationship

with that, the willingness of the patient to cooperate and his motivation to maintain an adequate regimen of oral hygiene after the fabrication of the implant-supported restoration are significant. No less important is the correct design of compensation.

Another possible cause of resorption is overloading of the implant and peri-implant bone support during oral functions. Therefore, balancing the functional loads and resistance of the implanted supports and their bone support is another absolute prerequisite for the durability and functional efficiency of the implants and the compensation they carry. This is achieved by adequately designing and consistently implementing the therapy plan. The surgeon and the prosthetist must participate in the conception of the therapy plan.

Brief description of the draft image

The invention is described in detail on the drawing, where we distinguish the implant support, the transmucosal part (implant neck) and the intreoseal part (implant body).

Detailed description of the invention

The drawing shows a screw endosseous dental implant consisting of an implant carrier (1), a transmucosal part (2), and an intraosseous part (3). Each endoosseous implant consists of three basic parts: - intraosseous, the part or body of the implant that is surgically inserted into the bone of the residual ridge, - the intraoral part that protrudes into the oral cavity and to which the compensation will be attached, which is called the implant carrier, and - the transmucosal part or the neck of the implant that connects the intraosseous with the intraoral part. The boundary between the implant support and the transmucosal part marks the location of the gingival margin of the crown and can be compared to the demarcation of the preparation on the natural supports of fixed restorations. The technique of installing a screw or screw implant is, regardless of the existence of a number of systems, in principle either similar or equal. The same instrumentation can be used for most systems. Once one method is described, all other installation techniques are understandable and comprehensible. For the installation of spiral or screw implants, a flap can be made, but the implantation can also be done without forming a mucoperiosteal flap. They are installed individually, when one tooth is missing or as supports for larger structures. The installation technique should be gradual, with minor trauma to the mucoperiosteal flap and bone tissue. The incision is made either only in the middle of the alveolar ridge or at an angle forward, or the alveolar ridge is exposed completely from the mucoperiosteal covering, i.e. it is peeled both lingually (palatally) and literally. After the lobe is excised, with a special drill that is narrower than the diameter of the future spiral implant, the middle of the alveolar crest is aimed and at right angles to its horizontal plane, a perforation is drilled for the length of the future implant screw. Then, with the three-threaded pre-screw, on which there are vertical notches, a three-thread line is formed using a hand wrench and a finger wrench. Vertical pressure should be applied on the finger wrench. After the bone chips are washed out, the perforation is formed with pre-screws with four, five or more threads depending on the number of threads on the implant to be installed. The number of threads on the pre-screw corresponds to the number of threads on the implant. The implant extends 0.25 microns from the lead screw. The posterior thread of the definitive screw should enter one millimeter below the cortical part of the bone. It is especially important during the installation to maintain the direction and dose the force in order to save the cortex from the load. The wound is sutured and after removing the sutures, definitive prosthetic work can be done. Tramonte created the original, self-tapping screw implant. Installation of this implant requires an incision, the formation of a flap. Then, with a special initial drill, the cortical part of the bone is trepanned to a depth of several millimeters, and with a conical drill, with a low number of revolutions, the surgical alveolus is shaped. With a digital and then a manual wrench, which achieves greater power, the pre-screw is placed and later, the implant is screwed in the same way. The implant is wider than the pre-screw, while the number of threads on the pre-screw and the implant is the same.

The relatively successful ones include Tramonte, bicortical screw implants, Oraltronics, KISS-bauer system, Chercheve, Heinrich, Muratori screws and others. The bicortical screw (Craltronics) is a single-phase implant that can be inserted immediately after tooth extraction or later. With special drills, of a specific profile, and with the help of a finger and hand wrench, the implant is installed to reach the cortex of the bone. It is used as an anchoring screw in a bridge or an intercanine edentulous ridge and after individual tooth loss. Today there are many modifications of screw implants. The bed for some of them is made blindly, without the formation of a mocoperiosteal flap. This method is done if the alveolar ridge is wide enough. In such cases, the bed is made with an initial and triangular drill and the implant is screwed with a finger and hand wrench. Today, drills with internal cooling are used for these purposes, which ensure a better success of implantation. These implants are immediately loaded, they heal fibroseally. Early loading is no guarantee of success. Success is even less if you do not work with drills with internal cooling. It is very risky to load these implants immediately after installation, because early and especially late failures are not excluded. The doctor does not always have to respect the requests of the patients. That kind of compromise usually leads to failure. Lederman created the TPS screw (Titanium Plasma Spray) intended for the prosthetic solution of the edentulous lower jaw. Four implants are placed in the symphysis part of the lower jaw, which are connected to each other with a factory overhang. The screw is self-tapping, 8 to 14 mm long, and 4.1 mm in diameter. The beds are prepared with special instruments, mostly by hand. First, the initial part of the bed is perforated with an initial drill, with abundant cooling. Since the screw is self-tapping, the bearing walls do not need to be tapped. The advantages are one-phase, one-piece and that the prosthetic work is made immediately after installation. Success rates for screw implants range from 63% after four years, to even 50%, to 93% after seven years. The Lederman screw, which is considered to be of the highest quality, has a success rate of 90% after eleven years. Installation of one-phase implants (Linkov, Tramonte, Bicortical, Kiss Bauer and a number of others) requires good bone quality, as well as satisfactory height and width of the alveolar ridge. It is considered that the installation of one-phase implants is justified if the implants are connected to each other with crossbars or are immediately covered by superstructures.

Implants are installed using a two-phase and one-phase method. The two-phase implantation of the implant involves covering the implant with a mucoperiosteal flap and leaving it at rest for four or six months. In the second phase, the implant is revealed (reoperation), wait for the soft tissue to heal and proceed to the fabrication of the superstructure. Some systems (ITI, steri oss, osseotite) are implanted in one phase, because they are not covered by a mucoperiosteal flap, and for them it is recommended to rest in the bone, so a suprastructure is made. Today, with a special treatment of the implant surface, and depending on the quality of the bone, its resting time is shortened to 6 to 8 weeks. Implants that are loaded immediately or very early, such as Linkovv leaf, Lederman, Tramonte Heinrich, bicortical, Kiss-Bauer, Muratori screw and a number of others, are installed in one phase. Bone quality and surface treatment have a decisive influence on their survival.

Whenever possible, a longer implant with a larger diameter should be substituted for a shorter and narrower implant. The prognosis for short and narrow implants is the worst, so failures are most common with implants shorter than 10 mm. Therefore, six or eight millimeter long implants are used only in special situations - a close relationship between the nose, sinuses and mandibular canal. The loss of one tooth from the incisor region of the premolar and molar was solved by making a fixed prosthetic work. Today, it is recommended that a tooth, extracted or lost due to trauma, be replaced by implantation after several months of bone healing, but also by an early and delayed immediate procedure. Installing an implant in the area of the upper front is much more demanding than installing it in the area of the molars. Aesthetic problems are most often related to the teeth in the upper front, especially when the implant is placed more labially. Receding of the gums in the area of the upper incisors occurs when there is bone loss or the labial lamella is severely thinned during the preparation of the implant bed. Also the low attachment of the frenulum of the lips and the line of ridge atrophy cause receding gums. That is why it is very important to pay attention to this during implantation and pre-implantation surgical preparation. The distance of the tip of the implant towards the sinus, nose and mandibular canal should be one to two millimeters. A "safety zone" must be observed when implanting in noisy areas of the lower and upper jaw. On the other hand, Bronnemark, as well as many other authors, claims that in the upper jaw, the implant can be placed above the border of the sinus floor, but under the condition that the membrane is not injured. They believe that the created hematoma organizes and further organization creates a solid bone callus. If two implants are installed in the lower jaw, the alveoli of the bone are measured with a vernier in the mesiodistal direction (direction) so that the implant beds are made in the appropriate place. For example, if two implants are placed in the intermental area, the distance must be 12 mm from the previously marked center on the alveolar ridge. It is sufficient to install two implants in the lower edentulous jaw, and four in the upper jaw, which is the minimum number of anchors for making prosthetic work. This attitude stems from the differences in the quality of the bone of the lower and upper jaw. For cylindrical implants, the bone width should be five millimeters, and for leaf implants 2.5 mm. For implants with a diameter of 3.3 mm, the ridge width should be from 4.5 to 5 mm, and for diameters of 3.75 and 4.1 from 5-6.5 mm and extremely large implant diameters are understood to require a much wider ridge - at least 7 mm. The ridge height for cylindrical implants should be 10 mm, and the diameter 3.3-4 mm. Solid screw implants are more commonly used because they can rarely fracture. They are easy to install, they are particularly mechanically stable and after correct installation we always receive them stable. Today there are shorter and longer implants that have specific indications. Also, implants of smaller and larger diameters are made, which are used in certain indications (minimum width of the alveolar ridge of seven millimeters). Six millimeter long implants are applied when the height of the ridge is insufficient, but in combination with longer implants. Finally, the diameter of the implant is chosen according to the width of the alveolar ridge, and the length according to the height of the ridge. Satisfactory ridge height and width and good bone quality are thought to ensure an implantation success rate of 95-100%. The distance between the two implants is 4 to 7 mm. It primarily depends on the diameter of the implant, because the minimum distance between them must be 3 to 4 mm.

The distance from the center of the implant to the cervical part of the adjacent tooth must be 5 mm, between the center of two implants 7 mm and from the center of the implant to the natural tooth (when making a bridge) the distance must be 11 mm. The distance between the two implants and the teeth as anchors for the bridge is 19 mm. The minimum distance between the installed implant and the adjacent tooth should be 0.25 to 1 mm, which ensures that the periodontal membrane is not injured. This is especially important for the marginal part of the periodontium, because otherwise bone resorption and implant loss always occur. Around the implant on the oral and vestibular side, the thickness of the bone after installation must be at least 0.5 mm. During installation, the angle and direction of the drill should be constantly controlled in order not to injure the outer or inner cortical lamella. During operation, drills are used in a down-up direction, at a reduced speed, and without pressure, in order to avoid the formation of a conical bed and to remove bone chips. Bone shavings should be collected to be mixed with bone substitutes in case of dehiscence during implantation. The drills are standardized to match the length and diameter of the implant body. After preparing the bed, its depth is checked with a gauge. While working in the bone, there is more or less resistance, no matter how new and sharp the drills are. The lowest resistance during the production of the tray is in the tuber, and the highest in the intercanine region of the lower jaw. When an implant is inserted, it happens that after perforating the compact, the drill passes through the spongiosa very easily, without resistance. In these cases, it is necessary to install one of the self-tapping implants. When the compact is mostly dense in structure, the bed should be made with a sharp, new drill, otherwise overheating and early loss of the implant will occur. All researchers and practitioners believe that overheating of the bone during the formation of the bed, along with high pressure during installation and premature loading of the implant, most often causes migration of the epithelium apically, which compromises the implantation in the early healing phase. During installation, placement in the bed, no greater force should be applied, especially when the implant is hammered in (cylinders). This is especially important with implants that are coated with hydroxylapatite or plasma coated with titanium beads or powder. In this way, their fine microstructure, surface is damaged, which causes their loss. If this happens, it is necessary to install a new, undamaged implant. Implant loading can be done immediately, and more often from two months to a year. It primarily depends on whether it is the lower or upper jaw, on the area of the jaw where it is implanted and the type of pre-implant surgical interventions, ridge augmentation, sinus floor elevation, vestibuloplasty, securing the attached gingiva, type of implant, immediate or late implantation and other reasons. Implant loss can be "early" and "late". With two-phase implants, early loss means loss before prosthetic work is made, while with one-phase implants, early loss means loss of the implant in the first two to three weeks. The primary loss of the implant occurs during the first year and is most often caused by a surgical error - dehiscence, overheating of the bone during the preparation of the bed, problems during healing, injury to the adjacent tooth, the appearance of instability, especially when short implants are installed. All of these are so-called iatrogenic reasons. Secondary implant loss is primarily a consequence of poor hygiene, plaque accumulation, infection and incomplete fusion to the bone, eventual fabrication of a prosthesis that is subject to soft filling (trauma) as well as incorrectly performed definitive prosthetic replacement.

Claims (1)

A screw is an endosseous dental implant that is inserted into the bone of the upper or lower jaw and to which a prosthetic work is attached, which can be a metal-ceramic crown or a bridge, characterized by the fact that it consists of an intraoral part, i.e. implant carrier (1), transmucosal part, i.e. the neck of the implant (2) and the intraosseous coil part, i.e. implant bodies (3).