RU2262325C1 - Screwed dental implant - Google Patents

Abstract

FIELD: medical engineering.

SUBSTANCE: device has body and head members having central hole for receiving screw and mating landing surfaces, and a screw joining them. The mating landing surfaces of the body and head members are shaped as regular n-angular truncated pyramid or truncated elliptic cone. The truncated pyramid or truncated elliptic cone height of the head member is greater than those of the body member. Implant is optionally produced with landing surface shaped as pyramid which lateral faces are concave towards its center. Implant is optionally produced with landing surface shaped as pyramid which lateral faces are convex outwards from its center. Ribs of said pyramid are optionally rounded.

EFFECT: high strength; stable tooth row occlusion.

4 cl, 7 dwg

Description

The invention relates to the field of dental implantology, namely to the design of a screw prefabricated dental implant, and is intended for use in surgical and orthopedic dentistry.

A known design of a screw dental implant, consisting of a housing and a head, the mutual position of which is ensured by the presence of conjugate conical landing surfaces [1].

The advantage of this design is the maximum load capacity of the implant with respect to the transverse bending moment, achieved both due to the large available length of the mating, and due to the fit of parts along the entire surface of the mating.

The disadvantage of the design is the lack of elements that ensure accurate mutual angular positioning of parts.

Also known is the design of a screw dental implant, in which the main conjugation of the body and the implant head is carried out on an elongated cylindrical surface, and the relative angular orientation of the parts is ensured by a short coaxial hexagonal prismatic connection, and the prismatic hole in the housing is also used as a key socket [2].

The advantage of the known design is the possibility of a unique mutual angular positioning of parts with a relatively high load capacity of the implant with respect to the transverse bending moment (due to the large total length of the mating).

A disadvantage of the known design is the presence of mounting gaps on all mating surfaces, which, with variable chewing loads, leads to micro displacements and a weakening of the screw preliminary tightening. In addition, surfaces collinear axis of the implant do not provide axial (occlusal) load transfer, and additional head support is also required. on one of the end surfaces of the housing.

Also known is the construction of a dental implant, in which a combined connection of the body and head in the form of a pair along a shortened circular cone and a hexagonal prism is used [3]. This design has two versions with parallel - Fig. 8 and with a sequential - Fig. 9 arrangement of the cone and prism. The advantages of this design in both versions are the exact (clearance-free) centering of parts in the radial direction and the possibility of their unique mutual angular positioning. At the same time, the design with a sequential arrangement of the cone and prism has a relatively good ability to withstand the transverse bending moment (due to the large total length of the pair). A design with a parallel arrangement of the cone and prism due to the smaller total length of the pair does not have such an advantage. Unlike the design by analogy [1], in which the parts were mated on a conical surface of considerable length, the design of the implant with the mate using a shortened cone cannot be considered completely gapless, since the short cone cannot perceive the transverse bending moment (they are actually removed not five, but only three degrees of freedom). As a result of this, angular displacements of parts occur within the gap in the prismatic part of the joint, which, as in the design similar to [2], leads to a weakening of the pre-tightening of the screw, that is, to a decrease in the reliability of the implant.

The problem to which the invention is directed, is to increase the load capacity and reliability of a screw implant.

The technical result of the invention lies in the fact that due to the conjugation of the housing and the head of the implant on the surface, providing gapless relative orientation of the connected parts in six coordinates, the load capacity and reliability of the implant are increased.

The technical result is achieved due to the fact that the screw dental implant contains a housing and a head made with a central hole for the screw and the paired landing surfaces, and a screw connecting them, and the paired landing surfaces of the housing and the head are made in the form of a regular n-angular truncated pyramid or truncated an elliptical cone, while the height of the truncated pyramid or truncated elliptical cone of the head is greater than the height of the truncated pyramid or truncated cone of the body. The implant can be made with a landing surface in the form of a pyramid, the side faces of which are made concave to its center. The implant can be made with a landing surface in the form of a pyramid, the side faces of which are made convex from its center. The edges of the pyramid may be made rounded.

The invention is illustrated graphic materials, which depict:

figure 1 - General view of the design of the implant;

figure 2 is a cross section of a pair in the form of a truncated pyramid with a base in the form of a polyhedron (hexagon);

figure 3 is a cross section of a pair in the form of a truncated elliptical cone with a base in the form of an ellipse (oval);

figure 4 is a cross section of the connection in the form of a truncated pyramid with a base in the form of a triangle with rounded edges;

figure 5 is a longitudinal section of a connection in the form of a truncated pyramid with flat faces;

figure 6 is a longitudinal section of a connection in the form of a truncated pyramid with faces concave to its axis;

7 is a longitudinal section of a compound in the form of a truncated pyramid with faces convex from its axis.

The proposed design of a screw implant (Fig. 1) consists of a housing 1, a head 2 and a screw 3 tightening them. Body 1 has a hole in the form of a regular n-angular truncated pyramid or a truncated elliptical cone, which smoothly passes into a cylindrical threaded hole for the tightening screw 3 The head 2 has a mating shank, the seating surface of which corresponds to the shape of the opening of the housing. In order to ensure that after tightening the screw, the interface between the body and the head is unique, the nominal length of the surfaces coming into contact with each part should be slightly larger than the actual contact zone (end contact is not allowed).

The configuration of the mating surfaces of the head and base of the implant in the transverse and longitudinal direction may be different. The cross-section of the mating surfaces can be in the form of a polyhedron, ellipse (oval) or a polyhedron with smoothly rounded edges (Fig.2-4). The shape of the side faces of the truncated pyramid of the mating surfaces of the head and base of the implant can be rectilinear or curvilinear, in particular concave to the axis of the implant or convex from its axis (FIGS. 5-7). Technologically, simpler is the multifaceted pyramidal mating surface depicted in the assembly in figures 1 and 5. The edges of the pyramid can be rounded.

Thus, the proposed technical solution provides a simultaneous solution of the following tasks:

- the implementation of the gapless connection of the housing and head with the deprivation of their six degrees of freedom relative to each other, which eliminates the relative micromotion of the implant parts and increases the reliability of the design;

- useful maximum use of the available length of the connection for the perception of axial load and lateral bending moment (there is a decrease in the level of contact pressure);

- the use of the entire available length of the profiled surface of the body as a turnkey socket, which prevents crushing of the body material when installing the implant.

The technical result of the invention also lies in the fact that:

- the claimed form of the mating surfaces of the head and body of the implant ensures diligence of the parts along the entire available length of the connection;

- the non-circular profile of the contour of the cross section of the mating surfaces of the head and body of the implant ensures their mutual angular orientation;

- the lack of contact between the body and the head of the implant on other (other than indicated) mating surfaces.

Analogs

1. ANKYLOS implant system, catalog of the company Degussa DE 823-2-2-896 N, 1996

2. The implant. Germany, No. DE 19829504 A1, Cl. MKI A 61 C 8/00.

3. The implant. Germany, No. DE 19705571 A1, Cl. MKI A 61 C 8/00.

Claims (4)

1. A screw dental implant comprising a housing and a head made with a central hole and mating landing surfaces, and a screw connecting them, characterized in that the mating landing surfaces of the housing and head are made in the form of a regular n-angular truncated pyramid or a truncated elliptical cone, with the height of the truncated pyramid or truncated elliptical cone of the head is greater than the height of the truncated pyramid or truncated cone of the body. 2. The implant according to claim 1, characterized in that the side faces of the pyramid are made concave to its center. 3. The implant according to claim 1, characterized in that the side faces of the pyramid are convex from its center. 4. The implant according to any one of the preceding paragraphs, characterized in that the edges of the pyramid are rounded.

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