WO2012011834A1 - Dental implant (variants) - Google Patents

Abstract

The invention relates to orthopaedic stomatology. The dental implant for dental prosthetics comprises a root portion in the form of an elongate form of an element with a blind opening, and a mobile base in the form of a rod which has been inserted into the cavity of the blind opening, wherein a resilient element is arranged on the bottom of said opening beneath the rod, as well as an element for fixing the rod in the root portion in the form of a screw. The resilient element is in the form of a disk spring or a set of disk springs, the rod is formed with a central stepped opening for the screw to pass through and to be screwed into the root portion, with the head of the screw being arranged in the rod opening having a large diameter. On the side opposite the side on which it is supported on the resilient element, the rod is formed with an element for attaching the orthopaedic structure and is cylindrical with a transverse dimension which exceeds the transverse dimension of the rod on the side on which it is supported on the resilient element.

Description

 Dental implant (options)

 Technical field

 The invention relates to medicine, namely to orthopedic dentistry, the section "implantology".

 State of the art

 The traditional methods of orthopedic treatment of patients with partial absence of teeth include prosthetics with fixed bridges, telescopic bridges, clasps, etc. An alternative method of treatment is the fixation of dental prostheses on osseointegrated implants. Therefore, the development of dental implants is currently being conducted from the standpoint of searching for bioplastic materials optimal for medical and technical characteristics for the manufacture of implants and improving the design of the dental implant itself.

 Modern materials are becoming more durable, their quality is increasing, the risk of complications is reduced, operational techniques are being modified, and treatment time is shortened.

For example, a one-stage screw implant of the Radix-Gimlet and Radix-Gimlet series of titanium is known, one of the advantages of which is its strength // Radix Dental Implant System. Product Catalog//. All components of the implant are made of titanium industrial cleaning (degree of purification - 1U). The surface of the implants is created by milling or sandblasting with particles of titanium dioxide. The implantable part is a self-tapping screw with a thread and parallel sides. The length and diameter of the implants to be installed is selected based on the height and width of the alveolar bone of the patients. The length of the implants is usually from 8 to 19 mm with a diameter of 3.5 and 4, .0 mm. The apical end of the implant is characterized by a narrower shaft, bearing the beginning of the apical thread. This thread is also intended for self-tapping in the cortical layer. The cutting grooves with wide surfaces allow for atraumatic distribution of self-cutting thread chips at the end of the implant. The apical part of the thread is expressed differently depending on the length of the implant. Minimal expansion in the transition region reduces the risk of germination of the epithelium in the cut structure of the thread and bone. Due to the stepped shape of the implant shaft, the effect of internal compensation is achieved. Due to this effect, when bone quality is unsatisfactory, bone is densified around the implant and thereby increased primary stability in the cancellous bone.

 However, any metal inclusions used as supports or connecting elements in bone tissue have a significant drawback - material tolerance. Traces of metal after a while are found in the blood, liver and other organs. In addition, the elastic modulus of a titanium implant differs significantly from the elastic modulus of the bone tissue into which it is implanted, which can lead to deformation of the bone tissue.

Dental implants made of a pyrocarbon material with a titanium rod are known. The length and diameter of the implants to be installed corresponds to the height and width of the alveolar bone of the patients. The length of the implants is from 8 to 19 mm with a diameter of 3.5 and 4.0 mm. Such an example of the construction of a dental implant made of monolithic pyrocarbon is described in RU N ° 53142, A61C13 / 10, publ. 05/10/2006, Carbon-based materials do not have pathogenicity, do not cause pronounced uncompensated damage to tissue structures when implanted in bone defects. Pyrocarbon does not inhibit adaptive bone remodeling. As a result of reactive processes developing in bone tissue during implantation of these materials, they are successfully integrated into the surrounding tissue structures. As an example, the authors propose a type of implantable artificial support in section with an internal titanium rod. An implantable artificial support of a conical shape with a length of 14.5 mm, a diameter of 4 mm, a diameter of the apical end 1 mm, a round profile thread and cutting grooves on the outer surface and a titanium rod 1 mm wide with a length of 4 mm.

 The disadvantage of this dental implant is that it is a monolithic structure, the strength of which is due to the physical characteristics of the material from which it is made. Since the teeth are constantly subject to dynamic loads, the value of which sometimes exceeds the strength characteristics of the material from which the implant is made, it is possible to destroy the crown or the implant itself or change its spatial position relative to adjacent teeth. The same picture is observed with an incorrect spatial arrangement of the implant, as a result of which the crown load is not on the entire surface, but has a local character.

A dental implant is known that contains a base element in the form of an artificial support inserted into the intraosseous space and is made in the form of a sleeve with externally located ribs, inside of which there is an elastic element such as a rubber washer with a central hole, as well as an abutment made with a head in which there is a hexagonal blind hole for installing the crown, and a cylindrical rod that is inserted into the cavity of the sleeve until it stops in the elastic element, while the rod is pulled through the hole in the rubber washer providing some damping of the abutment relative to the support, the abutment in the support is held due to the elastic clamping of its rod in the washer (EP JY ° 2076206, A61C8 / 00, A61C13 / 08, A61C13 / 225, publ. 08.07.2009). This decision was made as a prototype for the declared objects.

 The presence of an elastic element as a shock absorber can significantly reduce the effects of power overload of the tooth from external pressure. The disadvantage of this dental implant is that the abutment has the possibility of elastic displacement precisely along its axis under dynamic load on the artificial tooth (crown). Lateral loads are not damped, which can lead to deformation of the support or to incorrect spatial position of the tooth.

 In the article "Abutment with a Microshock Absorber" (author - Dr. Thomas

Lauks (University of Sarajevo), posted on-line on the Internet on the official "DENT" website of Adent, at: http://ident2.ru/ca ogue / abatments / agticle / states that "implanted in In comparison with natural teeth, bone implants exhibit an exclusively linear deviation, since they do not have a periodontal ligament of natural teeth, whose collagen structures play a special role in the reception and distribution of masticatory forces. The elastic connective tissue of the Sharpey fibers of the Desmodont is a kind of shock absorber in natural teeth when exposed to any mechanical force. Thus, the intrinsic mobility of a natural tooth under vertical load will be up to 20 microns.

 However, due to the ankylotic fixation of the implants in the surrounding bone tissue, the implants are inferior to the masticatory forces arising under a vertical load of only 2 μm. Therefore, mechanical overload of the implant can lead to fractures and cracks both in it and in the frozen abutment of the denture. It is also sometimes considered as an additional factor explaining the occurrence of peri-implantitis.

With the help of a titanium shock absorber mounted on the implant, synchronous mobility of the periodontal ligament of natural teeth and stationary implants in the bridge connection is ensured. The result of this is the achievement of a constant uniformity in the distribution of masticatory force on various bridge supports.

 According to the results of the FEM study, in fixed abutments, high-voltage regions with voltage peaks in the preimplantar cortical substance of the jaw bone and, especially, in the denture were found, while similar voltage peaks were not found in the abutment-shock absorbers, and the masticatory force was evenly distributed preimplantation cortex and denture. "

 Disclosure of invention

 The present invention is directed to solving the technical problem of creating a dental implant having the possibility of spatial self-installation (self-positioning) and damping of lateral and axial peak dynamic loads with the distribution of this load on adjacent teeth.

 The technical result of the invention is to improve the operational properties of the implant, increase its reliability and durability due to the formation of damping properties and self-installation in the implant under dynamic action with the function of load distribution.

The specified technical result for the first embodiment is achieved by the fact that in the dental implant for prosthetics containing the root part, made in the form of an oblong element with a blind hole, and a mobile base in the form of a rod inserted into the cavity of the blind hole, at the bottom of which under the shaft an elastic element is placed, as well as a rod fixing element in the root part in the form of a screw, the elastic element is made in the form of a disk spring or a set of disk springs, the rod is made from the center m stepped hole for passing the screw and screwing it into the root part with the screw head in the hole of the larger diameter rod, the rod on the side opposite to the elastic the element is made with an attachment element of an orthopedic structure and is made cylindrical with a transverse dimension exceeding the transverse dimension of the rod on the abutment side of the elastic element.

 The specified technical result for the second embodiment is achieved by the fact that in the dental implant for prosthetics containing the root part, made in the form of an oblong element with a blind hole, and a mobile base in the form of a rod inserted into the cavity of the blind hole, to the bottom of which is attached the end of the elastic element located in the cavity of this hole, the other end of which is pressed against the end surface of the rod, the elastic element is made in the form of an elastic block of polymer material or alloy or in the form of a coil spring, the screw part screwed into the bottom of a blind hole of the root part, the rod from the side opposite to the abutment side of the elastic block is made with an attachment element of the orthopedic structure and is made cylindrical with a transverse dimension exceeding the transverse dimension of the rod from the abutment side to the elastic block, while the section of the transition of the cylindrical part of the rod to the part based on the elastic element is made in the form of a fragment of a second-order surface, and the wall of the blind hole n and the contact area with the surface of the rod in the form of a fragment of a second-order surface and with the cylindrical surface of this rod is made repeating the outer surface of this rod.

 These features are significant for each embodiment and are interconnected with the formation of a stable set of essential features sufficient to obtain the desired technical result.

 Description of the figures of the drawings

The present invention is illustrated by specific examples of execution, which, however, are not the only possible, but clearly demonstrates the ability to achieve the required technical result.

 In FIG. 1 is a longitudinal section of a dental implant assembly, the first embodiment;

 FIG. 2 is a perspective view of a partial cutaway dental implant of FIG. one;

 FIG. 3 - a longitudinal section of the dental implant assembly, the second embodiment;

 FIG. 4 is a perspective view of a partial cutaway dental implant of FIG. 3.

 The best embodiment of the invention

 According to the present invention, two designs of a dental implant used for prosthetics of an artificial tooth are contemplated. At the same time, this implant is performed with the function of damping (damping) the load on the tooth and correcting the spatial position of the denture in the mode of self-installation (self-positioning). However, in the framework of the present invention does not address issues related to the use of special materials, metals or alloys.

According to the present invention, the dental implant for prosthetics of the first embodiment (Figs. 1 and 2) comprises a root portion 1 made in the form of an oblong shape of an element with a blind hole (the external structure or shape of this element is not of interest and is not affected in the description, is a root-shaped implant, performs the same role as the root of the tooth, therefore its location should be similar - the root implant should be surrounded by bone tissue and should not protrude from under the gums), and a mobile base in the form of a rod 2 inserted into the cavity of a blind hole, under which an elastic element 3 is placed. the element is made in the form of a disk spring or a set of disk springs.

 The rod from the side opposite to the abutment side of the elastic block is made with an attachment element of the orthopedic structure and is made cylindrical with a transverse dimension exceeding the transverse dimension of the rod from the abutment side of the elastic element. Section 4 of the transition of the cylindrical part 5 of the rod to the part based on the elastic element is made in the form of a fragment of a second-order surface (arc-shaped, sphere-shaped, etc.), and the wall of the blind hole in the area of contact with the surface of the rod as a fragment of the surface of the second order and with a cylindrical surface of this rod is made repeating the outer surface of this rod.

 The rod is made with a central stepped hole for the passage of the rod fixing element in the root part in the form of a screw and screwing it into the root part with the placement of the screw head in the hole of the larger diameter rod.

 The rod from the attachment side of the orthopedic structure can be made on the outer surface with an annular collar (not shown in the drawing) located above the end surface of the root part to limit the stroke of the rod during compression of the elastic element.

The dental implant for prosthetics of the second embodiment (Figs. 3 and 4) contains the root part 1, made in the form of an oblong element with a blind hole (the external structure or shape of this element is not of interest and is not affected in the description, it is a root implant forms, performs the same role as the root of the tooth, because its location should be similar - the root implant should be surrounded by bone tissue and should not protrude from under the gums), and the mobile base in the form of a rod 2 inserted into the cavity of the blind hole, under which the elastic element 3 is placed. One end of the elastic element 3 is attached to the bottom of the blind hole, the other end of this element is pressed against the end surface of the rod. The elastic element is made in the form of an elastic block of a polymeric material or alloy or in the form of a helical spring, a screw part 7 screwed into the bottom of a blind hole of the root part.

 The rod from the side opposite to the abutment side of the elastic block is made with an attachment element of the orthopedic structure and is made cylindrical with a transverse dimension exceeding the transverse dimension of the rod from the abutment side of the elastic block. Section 4 of the transition of the cylindrical part 5 of the rod to the part based on the elastic element is made in the form of a fragment of a second-order surface (arc-shaped, sphere-shaped, etc.), and the wall of the blind hole in the area of contact with the surface of the rod as a fragment of the surface of the second order and with a cylindrical surface of this rod is made repeating the outer surface of this rod.

 Thus, for both versions, the mobile support in the spring-loaded state has the possibility of some axial movement (depreciation mode) and angular displacement due to the interaction of the sphere-shaped contacting surfaces of the rod head and the recess in the wall of the blind hole. Angular displacements become possible due to the fact that any transverse dimension of the blind hole in the area from the sphere-shaped head of the rod to its exit from the blind hole is slightly larger than the transverse size of the rod (the presence of gaps). Angular offset is performed as part of the gap selection.

 A dental implant according to any embodiment is used as follows.

An orthopedic structure is mounted on top of the rod 2 from above and, for example, is fixedly screwed with the help of a thread and a screw. The load from this design is transferred to the mobile base and the elastic element, thereby thereby, compression of the elastic element and contact sliding of the second-order surfaces of the rod and the root part occurs, which leads to a dispersal of the load.

 Thus, the mobile support in the spring state has the possibility of some axial movement (depreciation mode) and angular displacement due to the interaction of the sphere-shaped contacting surfaces of the rod head and the recess in the wall of the blind hole. Angular displacements become possible due to the fact that any transverse dimension of the blind hole in the area from the sphere-shaped head of the rod to its exit from the blind hole is slightly larger than the transverse size of the rod (the presence of gaps). Angular offset is performed as part of the gap selection.

 Using a device for resonance frequency analysis, changes in the stability of implants in patients whose prostheses were made on abutments with dampers were measured. The indicators obtained in this study prove that the stability coefficients of the implants studied immediately after the installation of shock absorbers and load tests, even at various initial indicators, after a few weeks are equalized and demonstrate a high level of stability. In addition, during the study, not a single fact of a prosthesis fracture was noted. Therefore, a cushioned base with the possibility of angular positioning guarantees optimal biomechanics and optimizes prosthetics.

 Industrial applicability

 The present invention is industrially applicable, can be manufactured using known technologies used in the manufacture of implants in modern dentistry.

Claims

Claim  1. Dental implant for prosthetics containing a root part made in the form of an oblong element with a blind hole, and a mobile base in the form of a rod inserted into 5 a cavity of a blind hole, at the bottom of which a spring is placed under the rod, as well as a rod fixation element in the root part in the form of a screw, characterized in that the spring is made in the form of a disk spring or a set of disk springs, the rod is made with a central stepped hole for skipping the screw and screwing it into the root part with the screw head in the hole of the larger diameter rod, the rod on the side opposite to the abutment side of the elastic element is made with an attachment element opedicheskoy cylindrical construction and formed with a transverse dimension greater than the transverse dimension of the rod from the bearing 15 per elastic member.  2. A dental implant for prosthetics containing a root part made in the form of an oblong element with a blind hole, and a mobile base in the form of a rod inserted into the cavity of a blind hole, to the bottom of which one end is attached 20 located in the cavity of this hole of an elastic element, the other end of which is pressed against the end surface of the rod, characterized in that the elastic element is made in the form of an elastic block of a polymeric material or alloy or in the form of a coil spring, a screw part screwed into the bottom of a blind hole of the root part, side rod 25 to the opposite side of abutment on the elastic block, made with an attachment element of the orthopedic structure and made cylindrical with a transverse dimension exceeding the transverse dimension of the rod from the abutment side of the elastic block, while the transition section of the cylindrical part of the rod to the part resting on the elastic element, 30 is made in the form of a fragment of the surface of the second order, and the wall is deaf holes in the area of contact with the surface of the rod in the form of a fragment of the surface of the second order and with the cylindrical surface of this rod is made repeating the outer surface of this rod.