RU2285498C2 - Method for preparing bed for receiving intraosseous or cylindrical implant - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: method involves widening opening in cortical layer with mill. The hole is made deeper in the spongious bone layer with bore of the same diameter. The bed is made deeper in the same way using mills and bores of growing diameters. Mill rotation speed is 1.-2.0 times as large as the bore rotation speed.

EFFECT: prevented formed bed axis deviation; reduced injury intensity.

Description

The present invention relates to medicine, namely to surgical dentistry, and can be used for dental implantation.

The formation of the bone bed during dental implantation is one of the most important stages of the operation and the outcome of the operation and treatment as a whole depends on the quality of this manipulation. The quality of the preparation of the bone bed along with the quality of bone tissue significantly affects the primary stabilization, the process of osseointegration and the final stabilization of implants. Atraumatic bone preparation and bed precision remain the basic principles of implantation and are largely determined by the quality of instruments and surgical technique. This makes it relevant to develop new methods aimed at solving this problem.

Recently, the aesthetic requirements of patients to treatment have been significantly increased, and from this point of view, the responsibility lies not only with the orthopedic surgeon performing the “visible” part of the treatment, but also with the surgeon, whose task is to install artificial supports in a precisely defined place. To do this, before the operation, a template is made on which the installation sites of the implants are marked and, if necessary, their direction. However, during the operation, the doctor encounters certain difficulties associated with the anatomical features of bone tissue, such as a narrow alveolar ridge, loose bone tissue, severe atrophy of bone tissue. Good clinical conditions are less common than in 30%, in other cases the osteotomy is performed in such a way that the instruments for forming the bed are located at an angle of less than 90 ° to the bone surface. After working with a pilot drill in the cortical layer, one of the walls of the hole becomes higher than the opposite, further drilling goes in the direction of least resistance, sliding along the higher wall of the hole and removing bone tissue from a lower and thin wall. As a result, the axes of the installed implants do not correspond to the initially set ones, which can complicate the orthopedic part of the treatment and disrupt the aesthetics. In addition, with osteotomy, a split and fracture of the thinned cortical plate from the vestibular side of the alveolar ridge or exposure of a part of the implant may occur, which requires additional use of osteoplastic material and membranes or failure to install the implant.

For the prototype of the invention, a well-known method of forming a bed under an intraosseous screw or cylindrical implant is selected, including preliminary formation of the direction and depth of the bone bed and the subsequent expansion of holes with forming drills of gradually increasing diameter (V.L.Paraskevich Dental implantology: Fundamentals of theory and practice: Scientific.- Practical Guide, Publishing House Unipress LLC, Minsk, 2002, pp. 129-131, 230).

According to this method, the drill with which the channel is expanded should exceed the diameter of the formed channel by no more than 0.5-1.0 mm. For each implantation system, manufacturers recommend their own bone preparation rate, but the average frequency of rotation of the physiological desensor tip is in the range of 1000-1500 rpm.

The disadvantage of this method is that during osteotomy, an axis shift of the formed bed can occur. A particularly pronounced deviation during drilling can be with inclined alveolar processes of the jaws, which are often found in the frontal region, as well as with included and end defects of the dental arch, when the toothless area has a saddle shape due to atrophy of bone tissue. The same problem is encountered during direct implantation, when a bed under the implant is formed in the hole of the extracted tooth (on one of the walls of the hole) and the axis of the drill is located relative to the bone tissue at an angle of 30-40 °.

In addition, with osteotomy at revolutions of 1000-1500 rpm in conditions of poor access of coolant deep into the formed hole and low efficiency of internal cooling, local heating of bone tissue is possible, which can lead to postoperative inflammatory complications.

The objective of the invention is to eliminate the possible deviation of the axis of the formed bed under the implant, reducing bone injury, increasing the efficiency of treatment of patients using dental implantation.

The task is achieved by the fact that in the known method of forming a bed for an intraosseous screw or cylindrical implant, including preliminary formation of the direction and depth of the bone bed and the subsequent expansion of the hole with forming drills of increasing diameter, the hole is expanded in the cortical layer of the bone by guiding cutters of increasing diameter, then to deepen the hole in the spongy layer of the bone, a forming drill of the same diameter as the guide cutter is used, and soon The rotation of the guide cutter is 1.5-2 times higher than the rotation speed of the forming drill.

The present invention meets the criterion of "novelty", as the patent information research conducted did not reveal sources that discredit the novelty of the proposed solution.

The proposed method meets the criterion of "inventive step", as in the search process was not found technical solutions with essential features of the proposed.

The proposed method allows to obtain the following positive effect: firstly, as a result of the alternation of guide mills and forming drills during the osteotomy, the axis of the formed bed is not offset, which ensures aesthetics and rationality of prosthetics; secondly, the geometry of the guiding cutters reduces the mechanical trauma of the cortical layer of the bone, and a 1.5–2-fold decrease in the number of revolutions of the tip when working with a drill reduces the thermal trauma to the spongy layer of the bone, which reduces the risk of postoperative complications and contributes to good primary stabilization of the implant; thirdly, due to the preliminary expansion of the hole in the cortical layer of the bone, the cutter improves the removal of bone chips and the access of coolant deep into the formed hole, which also reduces the possibility of local heating of bone tissue; and, finally, due to the increase in the number and decrease in wear of each individual instrument, the service life of the instruments for forming the bed under the implant is increased.

Using the proposed method, implantation operations of screw intraosseous implants NIITOP (Nizhny Novgorod) were performed in 12 people, 23 implants were installed. In all cases, the implants were installed in a precisely installed place with the required angle of inclination, which was previously planned together with the orthopedist. During the osteotomy, there was no deviation of the axis of the formed bed, all implants were well initially stabilized, the postoperative period proceeded calmly. On the 8th day after the operation, the sutures were removed, in all cases the wound healed by primary intention.

To implement the method, a special guide cutter is used, which is a whole-made rod, consisting of a shank for fastening in the tip and the working part, which contains the cutting and guide elements. The guide element is a smooth pin of the same diameter as the tool with which the bed was drilled. The cutting part is made in the form of a cone with an angle of 5-7 ° with six cutting edges, which ensures atraumatic preparation and uniform removal of the bone layer around the entire circumference of the formed hole during immersion of the instrument in the bone tissue. The diameter of the base of the cone is equal to the diameter of the next drill. The cutting part ends with a 1 mm wide cylindrical girdle that does not carry cutting edges to exclude the injury of the cortical layer and remove the bone tissue layer around the hole circumference more than the diameter of the working part of the cutter. The length of the working part of the cutter corresponds to the length of the minimum size of the implant and is 9 mm, of which 4 mm is the length of the guide rod, 4 mm is the length of the cutting part and 1 mm is the width of the polished girdle at the base of the cutting part.

The cutter is made of titanium alloy with its subsequent heat treatment.

The method is as follows.

Before the operation, a template is made of transparent plastic (in a thermal vacuum apparatus), on which, together with the orthopedic surgeon, the implant placement sites are planned and holes 1 mm in diameter are formed in these places. If necessary, a template is made of quick-hardening plastic and not only the installation location is marked on it, but also the desired direction (axis) of the implants is set.

Under local anesthesia, a mucosal incision is made along the crest of the alveolar ridge in the region of missing teeth. The raspator exfoliates the mucoperiosteal flaps from the vestibular and oral sides. Inspect the alveolar ridge, smooth out all irregularities of the bone tissue with a milling cutter, then, according to the template, with the help of a spherical boron, the implant placement sites are marked. All work on bone tissue is carried out by a physiosensor with obligatory cooling with sterile saline. A pilot drill with a diameter of 1.8 mm sets the direction and depth of the bed under the implant. Then the osteotomy is performed by successive alternation of cutting tools according to the scheme: mill 2.5 mm - drill 2.5 - mill 3.0 mm - drill 3.0 mm - mill 3.5 - drill 3.5. The milling cutter is prepared at 1200-1300 rpm so that the cylindrical girdle enters the cortical layer of the bone and the base of the working part is at the level of the bone surface. Work is carried out in the cortical layer with intermittent reciprocating movements, to prevent overheating of the bone, sufficient irrigation of the formed bed with saline and good removal of bone chips. With a drill of appropriate diameter, the bed is deepened to a predetermined depth. Drill work is carried out in the spongy layer of the bone at 600-800 rpm. The diameter of the last drill depends on the quality of the bone tissue and should be 0.5-1 mm less than the implant diameter. Next, the cervical part of the bed is formed with a milling cutter for countersinking, the remaining bone shavings are removed from it with a curette spoon and washed with saline. With dense bone tissue, a thread is cut under the implant with a tap. An implant is inserted into the formed bed, its primary stabilization is achieved, and a plug is installed. Mucoperiosteal flaps are placed in place and fixed with separate interrupted sutures.

Clinical example.

Patient S., born in 1964, went to the dental clinic with complaints of the absence of 36 teeth.

Anamnesis: 36 tooth was removed 2 years ago due to chronic periodontitis.

Concomitant diseases: not notes.

Objectively: 35, 37 teeth are intact, their percussion is painless. The mucous membrane is pale pink, without pathological changes. The oral cavity is sanitized. The alveolar process in the region of the missing 36 tooth has a saddle shape. 5 mm wide, the distance between the necks 35 and 37-11 mm.

Diagnosis: partial loss of teeth of the lower jaw (Kennedy grade 3).

Additional examination methods: on the orthopantomogram, bone tissue in the region of 35-37 teeth corresponds to type 2 according to the Lekholm & Zarb classification, bone height to the lower alveolar nerve is 16 mm.

Clinical blood tests are within normal limits.

Treatment: 1) implantation of 2 screw implants D 3,5 L 13 in the region. 36 teeth;

2) prosthetics of 36 teeth with a ceramic-metal crown based on implants.

The patient is familiarized with the treatment plan, warned of possible complications.

Consent received for the operation.

07/03/2003. Operation: implantation of 2 screw intraosseous implants (NIITOP).

Under infiltration anesthesia sol. Ultrakaini 1.7 (2 carp.), A mucosal incision was made along the crest of the alveolar ridge between the 35th and 37th teeth, the mucoperiosteal flaps were peeled off, taken on catgut holders. According to a pre-made template, spherical boron outlines the placement of implants. The pilot drill made a distal guide channel 13 mm deep parallel to the medial root 37 of the tooth, a parallelometer (pin) was installed in it, parallel to which a 13 mm medial guide channel was made. Using the guide cutter, the cortical parts of the bed are expanded to a diameter of 2.5 mm, with a drill of 2.5 mm, the holes are deepened to 13 mm; the bed with a guiding milling cutter is expanded to 3.0 mm, with a 3.0 mm drill, the holes are deepened to 13 mm. A milling cutter was used to prepare the cervical part of the formed bed. A curette spoon was used to revise the formed bed, the chips were removed, and the wells were rinsed abundantly with a sterile 0.9% sodium chloride solution. Implants are introduced into prepared wells, initially stabilized, and plugs are installed.

Clinically and radiologically determined equal gaps between implants and teeth, equal to 1.5 mm, which indicates their correct installation. After antiseptic treatment with a solution of 0.02% furatsilina, the flaps were put in place, Polysorb sutures were laid. Dressing for a wound - solcoseryl dental adhesive paste, locally - cold.

Claims (1)

A method of forming a bed under an intraosseous screw or cylindrical implant, including preliminary formation of the direction and depth of the bed with a drill, subsequent expansion of the hole with cutting tools of increasing diameter, characterized in that they first expand the hole in the cortical layer with a cutter, then drill a hole of the same diameter to deepen the hole in the spongy layer bones, then in the same way they expand and deepen the bed with cutters and drills of increasing diameter, while the speed of rotation of the fr PS 1.5-2 times the rotational speed of the drill.