ES2934485T3 - Dental prosthetic system, for use with at least two dental implants - Google Patents

Abstract

A dental prosthesis system, for use with at least two dental implants, where the dental prosthesis is divided into a first prosthetic part (1) and a second prosthetic part (2), joined by a prosthetic screw (3), and where the The first prosthetic piece is connected to the dental implants through at least two connectors (4), and said dental prosthesis has a hooking and guiding system, which includes two female elements (6), arranged in the upper part of the first prosthetic part, and two corresponding male elements (5), arranged in the lower part of the second prosthetic part, so that the connection between the two female elements and the two male elements is releasable. The problems solved in the state of the art are related to a bending moment derived from masticatory forces. (Automatic translation with Google Translate, without legal value)

Description

DESCRIPTION

Dental prosthetic system, for use with at least two dental implants

field of invention

The present invention relates to a dental prosthetic system, for use with at least two dental implants, which is suitable for use in oral rehabilitation.

state of the art

Oral rehabilitations using osseointegrated implants have proven to be an effective solution, with evidence of good long-term results and that restores lost masticatory and aesthetic functions to the patient, as shown by Adell et al. (“A 15-year study of osseointegrated implants in the treatment of the edentulous jaw.” Int J Oral Surg. 1981;10(6):387-416), in Jemt T, Johansson J. (“Implant treatment in the edentulous maxillae: A 15-year followup study on 76 consecutive patients provided with fixed prostheses.” Clin Implant Dent Relat Res. 2006;8(2):61-9) and in Lindquist et al. (“A prospective 15-year follow-up study of mandibular fixed prostheses supported by osseointegrated implants.” Clinical results and marginal bone loss. Clin Oral Implants Res. 1996;7(4):329-36). However, due to different causes, the available bone volume can make dental implant placement difficult, either because prosthetically driven fixation placement can be compromised or because the use of implants of conventional dimensions is prevented by the proximity of important anatomical structures.

Therefore, in order to overcome this problem, the use of surgical procedures to restore bone contour and volume for prosthetically driven implant insertion, as well as for placement of implants of conventional dimensions, appears as an attractive option. The different surgical approaches comprise a vast group of bone grafts (autografts, allografts, xenografts, and synthetic bone grafts) and techniques, with multiple combinations (apposition bone grafts, interpositional bone grafts, guided bone regeneration, distraction osteogenesis, and split ridge). However, despite the reported success rates, these procedures are associated with costly treatments, more surgeries, more morbidity, more surgical complications, more treatment time, and an increased chance of failure. These factors make the patient and the dentist look for simpler, faster and cheaper solutions.

As an alternative, the use of short implants, placed over the available bone, is cheaper, faster and less invasive. This group of implants is particularly indicated when the amount of bone is reduced. In addition, the use of short implants makes more complex surgical approaches unnecessary. However, this solution can also present some drawbacks with respect to the compromised crown-to-implant ratio and the prosthetic result. Whenever necessary, resorting to prosthetic solutions to correct unfavorable implant positioning prosthetically can be a helpful and complementary approach.

Another option to overcome implant placement in a non-prosthetically oriented manner is the use of cemented prostheses. Cement-retained restorations have some advantages such as a better aesthetic result due to the absence of screw access and simplicity of use. However, they are also related to issues regarding the resiliency of the prosthesis, sometimes requiring the denture drilling to find the abutment screw, which can result in significant cosmetic damage and the need to replace the prosthesis. , as shown in Mehl et al. (“Retrievability of implant-retained crowns following cementation.” Clin Oral Implants Res.

2008;19(12):1304-11). However, the main problem identified with the use of cemented prostheses is the difficult excess cement removal and the possibility of developing peri-implant problems, ranging from peri-implant inflammation associated with swelling, bleeding and deeper probing, as well of signs of bone loss, as shown in Pauletto et al. (“Complications associated with excess cement around crowns on osseointegrated implants: a clinical report.” Int J Oral Maxillofac Implants. 1999; 14 (6) :865-8.). The use of angled abutments can also be considered as a possible approach in these cases that may allow the use of a screw-retained solution. The use of angled screw channels, also known as dynamic abutments, is also a solution for the same clinical problems, as stated in Ferreira et al. (“Fatigue and microgap behavior of a three-unit implant-fixed dental prosthesis combining conventional and dynamic abutments.” J Med Eng Technol. 2018; 42(5): 397-405).

A common and primary problem with regard to implant placement, without prior bone augmentation procedures, relates to the flexural forces generated on the prosthetic components, implants, and bone by a clinical prosthesis considerably higher than supporting implants and braces. possible adverse effects on bone tissue and on implants and prosthetic components, as shown in Calvo et al. (“Evaluation of extrashort 4-mm implants in mandibular edentulous patients with reduced bone height in comparison with standard implants: a 12-month results.” Clin Oral Implants Res. 2015;27:867-74) and in Verri et al. (“Biomechanical influence of crown-to-implant ratio on stress distribution over internal hexagon short implant: 3D finite element analysis with statistical test.” J Biomech. 2015;48(1):138-45). Similarly, the effect of bending moments produced by masticatory forces is also a concern since the elastic limit of bone is lower when the load is acting in a direction perpendicular to its principal axis.

Therefore, despite the documented safety of use, short implants may be associated with an increased risk of implant failure.

The justification behind this problem is based on the fact that masticatory forces, due to their horizontal component, create a bending moment that can generate high compressive and shear stresses in the marginal bone. As the use of short implants can be related to the need for long crowns, creating a higher crown-to-implant ratio, it can be assumed that the larger the crown, the greater the bending moment and, as a consequence, also the greater the possibility that greater tensions are generated, with possible detrimental effects, at the marginal bone level. The fulcrum for rotation resulting from the considered moment can be placed at the implant abutment interface, usually at the bone crest level.

Therefore, there is a need in the state of the art with respect to the development of long-term aesthetic and functional treatments, where "long-term" means biomechanical stability of hard and soft tissues and also stability of the materials used to replace the implants. lost tissues and missing teeth. In addition, there is a need to develop a dental prosthesis system where its main structural components can be able to resist the stresses generated by bending moments, which result in masticatory forces, while preserving the bone tissues that support the tooth. implant and prosthesis.

The document US2015111174 refers to implants for an artificial tooth that does not require a period, for the integration of the implant bodies and a mandible as in the prior art, allows the treatment even of a patient whose jaw is small in bone quantity or thickness. , it can reduce the treatment period and the number of treatment times for many patients, and can lighten a patient's mental and physical burden by minimizing the impact on the jaw.

US2003064349 discloses a dental appliance and provides a method of dental reconstruction in which a base is placed in or on a jaw, and one or more stabilizers engage the base to the jaw. A dental accessory is attached to the base. One piece dental implants are also provided.

Brief description of the drawings

In order to promote an understanding of the principles according to embodiments of the present invention, reference will be made to the embodiments shown in the figures and the language used to describe them. In any case, it will be understood that there is no intention to limit the scope of the present invention to the contents of the figures. Any subsequent changes or modifications to the inventive features herein and any further application of the principles and embodiments of the illustrated invention that would normally be presented to a person skilled in the art in possession of this disclosure are within the scope of the invention. claimed.

Figure 1 - is a front view of a dental prosthesis system, according to the present invention, connected to a model of a cortical bone;

Figure 2 is a front and side view of a dental prosthesis system, in accordance with the present invention, connected to a model of a cortical bone and a trabecular bone;

Figure 3 - is a view of a protruding male element and a slotted female element, used in one embodiment of the dental prosthesis system;

Figure 4 - is a view of a conical male element and a conical female element, used in one embodiment of the dental prosthesis system;

Figure 5 - is another view of a protruding male element and a slotted female element, used in one embodiment of the dental prosthesis system;

Figure 6 - is another view of a conical male element and a female element, used in one embodiment of the dental prosthesis system;

Figure 7 - is a cutaway view of one embodiment of the dental prosthesis system showing the protruding male element and a slotted female element, the implant and prosthetic screw channels, used in one embodiment of the dental prosthesis system;

Figure 8 - is a cut away view of an embodiment of the dental prosthesis system showing a conical male element and a female element, the implant and prosthetic screw channels, used in an embodiment of the dental prosthesis system;

Figure 9 - is a cutaway view of the assembly of both prosthetic parts showing a protruding male element and a slotted female element and the prosthetic screw, used in one embodiment of the dental prosthesis system; Figure 10 - is another cutaway view of the assembly of both prosthetic parts showing a conical male element and a female element and the prosthetic screw, used in an embodiment of the dental prosthesis system; and Figure 11 - is a view of a dental prosthesis system after incorporating anatomical bone and dental features.

Reference number list:

- a first prosthetic part (1);

- a second prosthetic part (2);

- a prosthetic screw (3);

- a connector (4);

- a male element (5);

- a female element (6);

- a projection as a male element (5a);

- a groove as a female element (6a);

- a conical or cylindrical extension as a male element (5b);

- a conical or cylindrical cavity as a female element (6b);

- a prosthetic screw channel (7);

- a model of a cortical bone (8);

- a model of a trabecular bone (9);

- an implant screw channel (10);

- a buccal face (11); and - a lingual face (12).

Detailed Description of the Preferred Embodiments

Reference will now be made in detail to preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or similar parts.

Taking into account the problems of the state of the art, the present invention is based on the installation of a mechanical weakness in the prosthesis to protect the bone tissue from the bending moment resulting from masticatory forces. The present invention explores the concept of a mechanical or structural fuse, which comprises the introduction of a sacrificial element that, in case of overload and/or fatigue, will break or deform and therefore protect the remaining structure. Transposition of this engineering concept to a clinical situation would result in fracture or necking of the sacrificial element avoiding the generation of a stress pattern that can result in marginal bone loss. At the same time, the sacrificial element must be strong enough to withstand normal masticatory function without failure and without allowing prosthetic movements that can make chewing uncomfortable. In addition, the scheduled replacement of the sacrificial element is a cost-effective solution and it is a solution that can be fully accepted by patients.

The present invention refers to a dental prosthesis system, for use with at least two dental implants, comprising: the dental prosthesis, which is divided into two parts, comprises a first prosthetic part (1), with a mesial, distal face , lingual and buccal, an upper section and a lower section, and a second prosthetic part (2), with a mesial, distal, lingual and buccal face, an upper section and a lower section; and having a prosthetic screw (3), where the prosthetic screw joins the first prosthetic part (1) and the second prosthetic part (2), and this prosthetic screw (3) acts as a sacrificial element; and where the first prosthetic part (1) is capable of connecting to the dental implants through at least two connectors (4), arranged in the lower section of the first prosthetic part (1); and which has a guide and coupling system, where the guide and coupling system includes two female elements (6), placed in the upper section of the first prosthetic part (1), and two corresponding male elements (5), placed in the lower section of the second prosthetic part (2), so that the connection between the two female elements (6) and the two male elements (5) is releasable.

The prosthetic screw (3) constitutes the sacrificial element subjected to a bending moment resulting from the masticatory forces that act on the dental prosthesis system, the implants and the bone tissue. The dental prosthetic system according to the present invention allows bone tension to be placed in a safe zone. According to Frost's mechanostat theory, above 60 MPa stress on bone, microdamage can begin to accumulate without repair and woven bone formation begins to replace lamellar bone formation. Therefore, this point is the equivalent to the elastic limit of bone tissue. In the dental prosthesis system model according to the present invention, this bone remodeling does not occur, because the stresses on the bone remain below the elastic limit of the bone tissue, while the prosthetic screw (3) is subjected to stress above its elastic limit.

Therefore, after a certain period, where the dental prosthesis system is subjected to shear stresses resulting from normal masticatory function, the mechanical weakness created by its division into a first prosthetic part (1) and a second prosthetic part (2), mounted by a prosthetic screw (3), acts by protecting the bone tissue from the generation of tensions related to the formation of bone tissue. Therefore, the prosthetic screw (3) is subjected to a stress above its elastic limit, since the other parts of the dental prosthesis system and the bone are subjected to stresses below their elastic limits. Ultimately, the prosthetic screw (3) fractures or deforms, preserving the bone tissue and prosthetic parts. If the prosthetic screw (3) breaks or deforms, this sacrificial element can be replaced and the dental prosthetic system reinstalled on the implants, resulting in a cost-effective solution for the patient and a practical solution for the dentist.

The prosthetic screw can also be replaced preventively periodically.

As illustrated in Figure 1, in a preferred embodiment of the present invention, a horizontal division of the dental prosthesis in a first prosthetic part (1) and a second prosthetic part (2), where the height of the second prosthetic part (2) is in a range of 20% to 80% of the existing crown height space. Preferably, the height of the second prosthetic part (2) is at least 50% of the existing crown height space. The crown height space here corresponds to the sum of the heights of the first prosthetic part (1) and the second prosthetic part (2).

In preferred embodiments according to the present invention, the crown height gap is equal to or greater than 5mm. According to Nissan et al. (“The effect of splinting implant-supported restorations on stress distribution of different crown-implant ratios and crown height spaces.” J Oral Maxillofac Surg. 2011;69(12):2990-4, there is a greater importance of crown height space than crown than the crown-to-implant ratio in generating stress, mainly at the crestal bone level.According to this study, the crown-to-implant ratio does not seem to be responsible for the problems reported with the use of short implants.Instead, the space of crown height plays a more relevant role, where from a crown height of 15 mm the effects of marginal bone loss can set in. Therefore, in tests using a first prosthetic part (1) and a second part prosthetic screw (2) that result in a crown height of more than 15 mm, the prosthetic screw (3) acts as a sacrificial element, subjected to a bending moment resulting from masticatory forces, preserving the bone tissue.

Therefore, the dental prosthesis system according to the present invention can be used in a wide range of crown height spaces. Preferably when the crown height gap is equal to or greater than 15mm, but can be used as long as the crown height gap is greater than the anatomical crown to be replaced.

The division of the prosthesis into a first prosthesis part (1) and a second prosthesis part (2) has introduced into the dental prosthesis system according to the present invention a discontinuity in such a way that the dental prosthesis system does not behave as a rigid body. By analyzing the stress pattern, contacts, and displacements in both prosthetic parts, it is possible to describe their mechanical behavior during the loading device. The second prosthetic part undergoes a rotation that is interrupted in the transition from the first prosthetic part (1) to the second prosthetic part (2). According to the model validation of the present invention, the second prosthetic part undergoes greater rotation than the first prosthetic part. Observing the tension generated in the buccal edge and the displacements of the second prosthetic part and the first prosthetic part, it can be stated that the center of rotation of the second prosthetic part is the edge along the first prosthetic part on the face. oral. Since this rotation is not counteracted by any structure, the slot coupling system also allows a small sliding of the second prosthetic part (2) on the first prosthetic part (1).

As illustrated in figure 2, in a more preferred embodiment of the present invention, the division of the dental crown into the first prosthetic part (1) and the second prosthetic part (2) has a slope in a range of 5 degrees to 25 degrees, where this slope is related to the horizontal plane formed by the lower section of the first prosthetic part (1) or the upper section of the second prosthetic part (2). Preferably, the division of the first prosthetic part (1) and the second prosthetic part (2) has a slope of approximately 10 degrees. This preferred embodiment potentiates the creation of a mechanical weakness in the prosthetic screw (3), which acts by protecting the bone tissue from stresses related to the formation of woven bone.

In figures 1 and 2, the dental prosthesis system is placed on a model of a cortical bone (8), which comprises in its inner part a model of a trabecular bone (9). The upper section of cortical bone (8) is intended to represent crestal cortical bone.

In the preferred embodiments of the present invention, where the interfaces between the first prosthetic part (1) and the second prosthetic part (2) are inclined, analyzing the displacements suffered by the dental prosthesis system, it is possible to confirm that the second prosthetic part (2) slides over the first prosthetic part (1), from the lingual side to the buccal side. The displacement of the second prosthetic part (2) results in a generation of a shear stress and a fracture or further deformation of the prosthetic screw (3). Therefore, the inclination of the interface between both prosthetic parts increases the possibility of creating a mechanical weakness in the prosthetic screw that can act to protect the bone tissue from stresses related to the formation of woven bone.

In the preferred embodiments of the present invention, where the interfaces between the first prosthetic part (1) and the second prosthetic part (2) are inclined, the height of the second prosthetic part (2) is equal to or greater than 5 mm depending on the height of the anatomical crowns that are proposed to be replaced, considering their buccal aspect.

In another preferred embodiment of the present invention, the first prosthetic part (1) has the dimension of a bone and gum, which the first prosthetic part (1) is intended to replace, and the second prosthetic part (2) has the dimension of the missing teeth, which the second prosthetic part (2) intends to replace.

As illustrated in figures 3, 5, 7 and 9, in preferred embodiments of the present invention, the coupling system is composed of two projections as male elements (5a) and two corresponding grooves as female elements (6a), where the two projections as male elements (5a) and the two corresponding grooves as female elements (6a) are placed transversely, respectively along the lower section of the second prosthetic part (2) and the upper section of the first prosthetic part (1 ). In other embodiments according to the present invention, the two corresponding grooves as female elements (6a) can be deeper than the length of the two protrusions as male elements (5a). The deeper characteristics of the two corresponding slots as female elements (6a) contribute to a greater rotation of the second prosthetic part (2) and, therefore, this increased rotation generates a greater shear stress on the prosthetic screw (3). .

As illustrated in figures 4, 6, 8 and 10, in other preferred embodiments of the present invention, the coupling system is composed of two conical or cylindrical extensions as male elements (5b) and two corresponding conical or cylindrical cavities as male elements. female (6b). In a preferred embodiment, the cavities as female elements (6b) correspond to the channels that lead to the connectors (4), where these channels are used to introduce and screw the implant screws to the implants.

In another preferred embodiment of the present invention, the material of the prosthetic screw (3) can be selected from various materials, for example, a metal, an alloy, a ceramic, a polymer or a reinforced polymer. Preferably, the material of the prosthetic screw (3) is selected from a titanium alloy, for example a grade V titanium alloy (Ti6A14V), an alloy of chrome-cobalt, zirconia and polyether ether ketone (PEEK), where the polyether ether Ketone is optionally reinforced with carbon fibers or glass fibers.

In another preferred embodiment of the present invention, the materials of the first prosthetic part (1) and the second prosthetic part (2) are selected from the group consisting of a metal, an alloy, a ceramic, a polymer, or a reinforced polymer. Preferably, the materials of the first prosthetic part (1) and the second prosthetic part (2) are commercial pure titanium, titanium alloys, for example grade V titanium alloy (Ti6A14V), cobalt-chromium alloys, zirconia, which represents the ceramic materials, and polyether ether ketone (PEEK), which represents the polymeric materials, where the polyether ether ketone is optionally reinforced with carbon fibers or glass fibers.

The implants on which it is possible to use the dental prosthesis system according to the present invention are all those commonly known in the prior art. Among others, the implants can be selected from endosseous implants, subperiosteal or ridge implants; trans-mandibular implants; blade implants; if the implant material is commercial pure titanium, titanium alloys, zirconia, titanium-zirconia alloys, aluminum oxide implants or others.

The dental prosthesis system according to the present invention can be connected to implants or intermediate abutments by means of implant screws, where the materials of the implant screws are selected from those commonly used, for example, a metal and an alloy. , usually prepared from a Ti6A14V ELI alloy. Alternatively, the dental prosthetic system can be connected to the implants using a cemented technique, where the abutment materials for cementation and cement materials are any of those commonly used for the same effect in the prior art. former.

The present invention also comprises a method for using at least two implants and the dental prosthesis system according to the present invention, which can be used in a huge field of applications, such as clinical situations associated with decreased bone volume. Examples of these clinical situations include missing teeth, which frequently result in severe bone remodeling, long-term use of removable dentures, clinical situations related to oncological diseases, such as marginal mandibulectomies or segmental mandibulectomies followed by mandibular reconstructions with different approaches, oral infections, eg periodontal or peri-implant diseases and trauma, eg mandibular fractures resulting from accidents.

The method of using at least two implants and the dental prosthesis system according to the present invention comprises the steps of:

a) Perform the placement of at least two implants in the mandible, if the surgeon's option is a free-hand technique, totally guided or partially guided, if it is an immediate, delayed or late implant placement and if it is a a flap or flapless procedure;

b) Placing the dental prosthesis system according to the present invention attached to the implants.

In the method of using at least two implants and the dental prosthesis system according to the present invention, the implant placement step must follow the drilling protocols recommended by the chosen implant manufacturer.

During the placement process of the dental prosthesis system, the first prosthetic part is attached to the implants in two possible ways:

a) Screwed, using the appropriate torque, directly to the implant platform or to intermediate abutments.

b) Cemented to pillars screwed to the implants for this purpose.

The second prosthetic part is then attached to the first, by means of the prosthetic screw, with precise torque, using a controlled torque device.

The following examples are for the purpose of illustration only and are not to be construed as limiting the scope of the invention in any way.

Examples 1 to 3 are simulations under a finite element analysis (FEA), which is widely used in dental implantology, to evaluate the biomechanical behavior of living tissues and restorative materials. The use of this method allows the multiplication of tests in a short period of time, varying the critical factors of each experience, in a way that would be uninhabitable with experimental biomechanics or animal and clinical tests.

The FEA analysis used to evaluate the present invention considered bone as a transversely isotropic material, in accordance with the methodology known in O'Mahony et al. (“Anisotropic elasticity of cortical and cancellous bone in the posterior mandible increases peri-implant stress and strain under oblique loading.” Clin Oral Implan Res. 2001; 12 (6):648-57).

In order to bring the mathematical model as close to reality as possible, the model parts were designed based on measurements made directly on CT scans of real patients, product catalogs from implant companies, and reverse modification methods. The interactions between the different parties respected the real situation. For example, to simulate the osseointegration of dental implants, the three model parts "cortical bone", "trabecular bone" and "dental implants" were merged in the "montage" menu of the abaqus software, used in the FEA analysis, retaining part boundaries, which made it possible to assign different materials.

The loading conditions were collected from the literature to simulate real conditions according to Baca et al. (In vivo evaluation of occlusal contact area and maximum bite force in patients with various types of implant-supported prostheses. Acta Odontol Scand. 2013;71:1181-7).

A mesh sensitivity analysis was performed and the mathematical models were experimentally validated.

Example 1

Table 1 presents the results related to a comparison of the calculated stresses, microseparation and displacements, between a reference model (conventional one-part denture frame) and an inclined plan model of the dental prosthesis system (split denture frame).

The results of table 1 were established in a simulated model according to a present invention, where the division of the dental crown into the first prosthetic part (1) and the second prosthetic part (2) had a slope of 10 degrees. In this model, a conical extension was used as a male element (5b) that fits into the implant screw channel placed in the first prosthetic part (6b). The model was specified with two connectors (4), a crown height gap of 25 mm, and the height of the second prosthetic part (2) was 7 mm on the buccal side of the denture system, in order to simulate a Average clinical mandibular molar and premolar crown height. In this simulated model, M 1.4 prosthetic screws were designed. During the simulation, the following materials were assigned to the parts: the prosthetic screw and implant screw, the Ti6A14V alloy, the prosthetic parts and prostheses, the chrome-cobalt alloy, and the implants, commercial grade IV pure titanium.

T l 1 r l l m l 1

Analyzing Table 1, it is possible to observe that the stress obtained in the implants suffered a decrease from 454.2 MPa in the reference model to 301.4 MPa in the model according to the present invention. Comparing the stresses calculated in the implant-abutment connection, considering the prosthesis part for the reference model and the first part prosthetic for the model according to the present invention, and also comparing the stress calculated on the implant screws, the present model shows a decrease in stress values in both parameters. The microseparation, which in the numerical simulations represents the distance between the implant platform and the prosthesis connectors, calculated based on the movement of the prosthetic part at the level of the connectors and not resulting from a bad fit, also shows a lower value in the model according to the present invention, which indicates a micromotion of smaller amplitude than that predicted for the reference model.

These results reflect a new solution, where biological tissues can be preserved and prosthetic components show a stress pattern below plastic deformation, where the prosthesis is divided into two parts, one representing the teeth and the other representing the tooth. lost bone, where its mounting is done by means of a prosthetic screw, which acts as a cutting screw.

Example 2

It is possible to increase the shear stress on the prosthetic screw with even greater magnitudes, allowing its fracture, before the bone has reached a state of stress compatible with bone remodeling. When the stress applied to the bone is greater than 60 MPa, microdamage can begin to accumulate without repair and woven bone formation begins to replace lamellar bone formation. In order to potentiate the action of the prosthetic screw as a sacrificial element, it is necessary to expose the prosthetic screw to the effect of a horizontal component of the applied load. This force component is responsible for the rotation of the second prosthetic part, which is greater than the rotation of the first prosthetic part, resulting in bending and shear stresses and a removal movement of the prosthetic screw.

The results in Table 2 were established in a simulated model according to a present invention, where a protrusion was used as a male element (5a) and a groove as a female element (6a), where the groove was deeper than the length of outgoing. The model was specified with two connectors (4), a crown height space of 25 mm and the height of the second prosthetic part (2) was 6 mm, in order to simulate a clinical molar and pre-molar crown height. average jaw. In this model, M 1.4 prosthetic screws were designed. During the simulation, the following materials were assigned to the parts: to the implant screw, the Ti6A14V alloy, to the prosthetic parts, the chrome-cobalt alloy, to the implants, pure commercial grade IV titanium, and to the prosthetic screw, the PEEK unfilled.

T l 2 r l l m l 2

Example 3

Another possible approach to increase the effects of the horizontal component of the applied load on the prosthetic screw is to increase the height of the second prosthetic part (2) relative to the first prosthetic part (1). This would result in an increase in torque and therefore a higher shear stress at the prosthetic screw level.

The results in Table 3 were established in a simulated model according to a present invention, where the height of the second prosthetic part (2) was half the existing crown height space. In this model, a projection was used as the male element (5a) and a groove was used as the female element (6a), where the groove was the same length as the projection. The model was specified with two connectors (4) and a crown height gap of 25mm. Conventional M 1.4 prosthetic screws were used in this model. During the simulation, the following materials were assigned to the parts: to the implant screw, the Ti6A14V alloy, to the prosthetic parts, the chrome-cobalt alloy, to the implants, pure commercial grade IV titanium, and to the prosthetic screw, the PEEK unfilled.

T l r l l m l

As shown in Tables 2 and 3, the calculated results of the finite element analysis place the bone tissue in a safe stress zone as long as the prosthetic screw exceeds the elastic limit. Due to all the approximations, assumptions and simplifications during the finite element analysis, the numerical model was validated experimentally. For this purpose, an experimental model was designed and manufactured. The choice of a 30-degree slope load model, also used in the numerical simulation, proposed to equate the physiological forces that result from chewing and was determined because said slope corresponds to a worst case scenario. In addition, said slope is specified in the ISO 14801 standard, which governs fatigue tests on dental implants.

The model manufactured according to a present invention to validate the simulations carried out comprised a height of the second prosthetic part (2) established as half of the existing crown height space. In this fabricated pattern, a projection was used as the male element (5a) and a groove was used as the female element (6a), where the groove was the same length as the projection. The model was specified with two connectors (4) and a crown height gap of 25mm. Conventional M 1.4 prosthetic screws were used in this model. During the fabrication of this model, the prosthetic parts were made from cobalt-chromium alloy, the implant screw was made from Ti6A14V alloy, and the prosthetic screw was made from unfilled PEEK. For economic reasons, the implant simulators were used since the alloy from which they are composed, Ti6A14V alloy, has elastic properties in the same range as commercial grade IV pure titanium. The resin that replaces the bone part was an epoxy that complies with the standards of ⁱ S ^or 14801.

After the final configuration geometry was established, four samples were subjected to a quasi-static load compression test. The test was stopped when the applied load magnitude recording showed a sharp decrease.

During the test, it was verified that the second prosthetic part rotates and slides over the first one, creating an open joint on the lingual side. As a result, it was possible to observe that the unfilled PEEK prosthetic screw of samples 1 and 2 underwent a narrowing process characterized by the reduction of the diameter and the elongation of the body of the screw and in samples 3 and 4 the experiment ended with the fracture. screw. In all samples, the bone-replacement resin, implants, implant screws, and both prosthetic parts remained undamaged.

The described experimental behavior exhibited by the samples is similar to that shown by finite element analysis. The second prosthetic part undergoes a sliding movement and a rotation of greater dimension than the first part which creates an open lingual articulation. This phenomenon generates shear and bending stresses in the prosthetic screw, which exceed the elastic limit of the material, resulting in screw deformation (narrowing) or fracture. For the same load, the other components of the model show stresses below the elastic limit of the corresponding materials.

However, it will be understood by those skilled in the art that in other alternative embodiments the prosthetic parts of the dental prosthetic system according to the present invention may be fabricated after including anatomical features of teeth and bones, such as tooth geometries, such as is shown in Fig. 11. In the embodiment shown in Fig. 11, an inclined plane model was incorporated into a dental prosthesis system according to the present invention, considering the anatomical characteristics of bone and teeth.

In addition, the dental prosthetic system according to the present invention is suitable for connection to both external connection implants and internal connection implants, for example Morse taper internal connections with the integration of the platform switching concept.

The dental prosthesis system according to the present invention is also suitable for connection to intermediate abutments, eg straight or angled multiple unit type. The first prosthetic part of the dental prosthetic system according to the present invention is also suitable for connection to implants by means of a cemented approach. The first prosthetic part of the dental prosthetic system according to the present invention can also incorporate the concept of an angled screw channel.

As used herein, the term "longitudinal" refers to a cut plane of a device or component comprised of the largest dimension in this device. On the other hand, the term "transverse" refers to the cut plane of a device or component comprised in the smallest dimension in this device. The terms "about" and "approximately" are understood to refer to a range of values of plus or minus 10% of the specified number.

The term "substantially" is understood to refer to a condition that the actual value is within the range of about 10% of the desired value, variable or related limit, particularly within about 5% of the desired value, variable or related limit or especially within about 1% of the desired value, variable, or related limit.

The subject matter described above is provided as an illustration of the present invention and should not be construed as limiting it. The terminology employed for the purpose of describing specific embodiments in accordance with the present invention should not be construed as limiting the invention. As used in the description, the definite and indefinite articles, in their singular form, are intended to be construed to include the plural forms as well, unless the context of the description explicitly states otherwise. The terms "comprising" and "include", when used in this disclosure, shall be understood to specify the presence of related features, elements, components, steps and operations.

Claims (14)

1. A dental prosthesis system, for use with at least two dental implants, characterized in that it comprises: The dental prosthesis, which is divided into two parts, comprises a first prosthetic part (1), with a mesial, distal, lingual and buccal face, an upper section and a lower section, and a second prosthetic part (2), with a mesial, distal, lingual and buccal face, an upper section and a lower section; and it has a prosthetic screw (3), where the prosthetic screw joints, the first prosthetic part (1) and the second prosthetic part (2), and this prosthetic screw (3) acts as a sacrificial element; and where the first prosthetic part (1) is capable of connecting to the dental implants through at least two connectors (4), arranged in the lower section of the first prosthetic part (1); and having a guide and coupling system, where the guide and coupling system includes two female elements (6), placed in the upper section of the first prosthetic part (1), and two corresponding male elements (5), placed in the lower section of the second prosthetic part (2), so that the connection between the two female elements (6) and the two male elements (5) is releasable. 2. The dental prosthesis system, for use with at least two dental implants, according to the preceding claim, characterized in that its division into the first prosthetic part (1) and the second prosthetic part (2) is horizontal and the height of the second prosthetic part (2) is in a range of 20% to 80% of the existing crown height space. 3. The dental prosthesis system, for use with at least two dental implants, according to claim 1, characterized in that its division into the first prosthetic part (1) and the second prosthetic part (2) has a slope in a interval from 5 degrees to 25 degrees, where said slope is related to the horizontal plane formed by the lower section of the first prosthetic part (1) or the upper section of the second prosthetic part (2). 4. The dental prosthesis system, for use with at least two dental implants, according to the preceding claim, characterized in that the height of the second prosthetic part (2) is equal to or greater than 5 mm on the side where the second prosthetic part (2) is taller along a longitudinal plane by a crown height space corresponding to the sum of the heights of the first prosthetic part (1) and the second prosthetic part (2). 5. The dental prosthesis system, for use with at least two dental implants, according to any of the preceding claims, characterized in that the crown height space is equal to or greater than 5 mm. 6. The dental prosthesis system, for use with at least two dental implants, according to any of the previous claims, characterized in that the first prosthetic part (1) is configured to have the dimension of a lost bone and gum of a patient that the first prosthetic part (1) is intended to replace, and the second prosthetic part (2) is configured to have the dimension of the patient's missing teeth, which the second prosthetic part (2) is intended to replace. 7. The dental prosthesis system, for use with at least two dental implants, according to any of the preceding claims, characterized in that the coupling system is made up of two projections as male elements (5a) and two corresponding grooves as elements female (6a), where the two projections as male elements (5a) and the two corresponding grooves as female elements (6a) are placed transversally, respectively along the lower section of the second prosthetic part (2) and the section upper part of the first prosthetic part (1). 8. The dental prosthesis system, for use with at least two dental implants, according to the previous claim, characterized in that the two corresponding grooves as female elements (6a) are deeper than the length of the two projections as male elements. (5a). 9. The dental prosthesis system, for use with at least two dental implants, according to any of claims 1 to 6, characterized in that the coupling system is made up of two conical or cylindrical extensions as male elements (5b) and two corresponding conical or cylindrical cavities as female elements (6b). 10. The dental prosthesis system, for use with at least two dental implants, according to the previous claim, characterized in that the cavities as female elements (6b) correspond to the channels that lead to the connectors (4), where these channels (10) are used to introduce the implant screws. 11. The dental prosthesis system, for use with at least two dental implants, according to any of the preceding claims, characterized in that the material of the prosthetic screw (3) is selected from the group consisting of a metal, an alloy, a ceramic, a polymer or a reinforced polymer. 12. The dental prosthesis system, for use with at least two dental implants, according to the preceding claim, characterized in that the material of the prosthetic screw (3) is selected from a titanium alloy, for example a grade V titanium alloy (TI6A14V), an alloy of cobalt chromium, zirconia and polyether ether ketone, where the polyether ether ketone is optionally strengthened. 13. The dental prosthesis system, for use with at least two dental implants, according to any of the preceding claims, characterized in that the materials of the first prosthetic part (1) and the second prosthetic part (2) are selected from the group consisting of a metal, an alloy, a polymer, a reinforced polymer, or a ceramic. 14. The dental prosthesis system, for use with at least two dental implants, according to the preceding claim, characterized in that the materials of the first prosthetic part (1) and the second prosthetic part (2) are selected from the group that consists of titanium alloys, for example grade V titanium alloy (Ti6A14V), cobalt-chrome alloys, titanium, zirconia, representing ceramic materials, and polyether ether ketone (PEEK), representing polymeric materials, where polyether Ketone ether is optionally reinforced with carbon fiber or glass fiber.