CH703012A1 - Implant, particularly dental implant for implant system for assembly set, has distal end for implanting in jawbone and proximally accessible twisting or anti-twisting plate structure in implanted condition - Google Patents

Abstract

The implant (1) has a distal end for implanting in a jawbone and a proximally accessible twisting or anti-twisting plate structure in an implanted condition. The twisting or anti-twisting plate structure is concave or convex curved in a section perpendicularly to an axle along a circumferential line. The surface of twisting or anti-twisting plate structure has concave or convex circular arc sections in the section perpendicularly to the implant axle. Independent claims are also included for the following: (1) an implant system with an assembly part; and (2) an assembly set with a thread.

Description

The invention is in the field of medical technology and relates to a dental implant.

An important category of implants are implants, which in addition to the actual implant body, which has the bone anchored in the enossal area, also have a so-called abutment. Such is used in most cases for attaching a tertiary element, such as a crown or a prosthesis. Such implant systems are generally subgingival, i. The implant body is covered under the gum for the healing. The abutment is primarily applied only after the implant body has healed. Often, the literature also speaks of two-part implant systems; This term is usually used interchangeably with subgingival implant systems.

In contrast, there are the transgingival implant systems, in which the implant protrudes through the gum, and in which implant and abutment are already together during implantation and are usually integral with each other. Often such transgingival implants are also referred to as one-piece implants.

In two-piece implants, the implant body is often made of a ductile material such as titanium or a titanium alloy. In general, the abutment - which can also be made of a ductile material - attached with an abutment screw on the implant body.

Implants of a brittle ceramic such as oxide ceramics (zirconium oxide-based ceramic, alumina-based ceramic), however, are usually one-piece, as a screw because of the low elongation at fracture of the materials designed as difficult. Also known from the literature are today two-piece implant systems made of ceramic, in which the connection of the abutment and implant by sticking (often "cemented") takes place.

All screwed into the bone implant systems, whether one-piece or two-piece, are screwed into the bone by a Eindrehmoments is recognized by means of a screwing. The geometry, which transmits the torque from the insertion tool to the implant body, are not least limited by the production possibilities.

In particular, two-piece implants may also be designed so that they are not screwed into the bone, i. during the actual implantation no torque has to be applied. However, such two-part implants also have a geometry which, after the healing has taken place and the abutment has been secured, effects an anti-rotation lock between the implant body and the abutment. The same may be the case for preventing rotation between - even one-piece - implant and tertiary element (crown prosthesis, etc.), for example, even if the implant is given a primary stability by means other than a thread, for example according to WO 2004/017857 ,

For ductile, metallic materials, the geometry for the transmission of torque can be produced both by machining (milling, turning) and by forming or by appropriately shaped broaching tools. With brittle-hard materials, the latter is not possible.

A common screw-in and / or anti-rotation structure is a Innenpolygonprofil, in particular an inner hexagon (US 4,960,381) or an inner octagon. Furthermore, implant systems are known which are based on suitable tooth structures, see, for example, US Pat. No. 5,823,776. All these solutions have in common that locally high loads occur in the area of edges and that the production in connection with brittle-hard implant materials is difficult.

From US Pat. No. 6,733,291 an implant with a screw-in and / or anti-rotation geometry without edges is known. This geometry is formed by a proximal open chamber in the implant body, which in addition to a circular cylindrical basic shape has a plurality of furrows - for example, three furrows - with circular cylindrical boundary, the furrows are distributed uniformly along the periphery of the circular cylindrical basic shape. The absence of sharp edges or corners is considered an advantage according to US 6,733,291. Nevertheless, this form also has locally high loads, for example at the base of the furrows. In addition, the production is not trivial, especially in brittle-hard materials.

It is an object of the invention to provide an implant that has a screw-in and / or anti-rotation, which overcomes the disadvantages of the prior art and which in particular locally greatly increased loads avoids and thereby also the risk of breakage during use reduced by brittle materials. Preferably, the geometry is also advantageous in manufacturing.

An implant according to one aspect of the invention has a distal, enossal area for implantation in the jawbone and in the implanted state of proximally accessible insertion and / or anti-rotation structure. The screw-in and / or anti-rotation structure may have an internal structure, i. have a proximal open bore / chamber with a non-rotationally symmetrical inner contour into which a lot of the body part (abutments or possibly other, tertiary element) with a correspondingly designed outer contour can be inserted. But it can also have an external structure, i. a region having a non-rotationally symmetrical outer contour along the circumferential surface, which is encompassed by a structural part provided with a corresponding inner structure. The screw-in and / or anti-rotation structure is characterized essentially by the fact that the inner or outer contour is curved concave (inner structure) or convex (outer structure) substantially everywhere in a section perpendicular to an axis along a circumferential line.

In the present text, "implant" refers to a dental implant which is intended to be implanted in the bone tissue at least in an endosseous area; the implant may be subgingival or have an area protruding through the gum ("posts"). An implant system has, in addition to the implant, at least one body part. As body parts here are both so-called "abutments" -. for example, transgingival parts having a structure (post) for securing a tertiary part (a crown, prosthesis, bridge, or cap or another abutment) - as well as directly (directly) to be attached to the implant crowns. Prostheses, bridges. Caps etc. referred.

The terms "proximal" and "distal" are used in the present text in relation to the implantation direction. In general, the distal direction corresponds to the direction toward the apical end of the dental implant (or tooth), while the proximal direction corresponds to the coronal direction.

It is not excluded that other, not contributing to the function of the screw-in and / or anti-rotation structure structures are available which deviate from the concave or convex contour. Such other structures may also be present on the implant and / or on the mounting part in the region of the corresponding screw-in and / or anti-rotation structure and, for example, serve as channels for the flow of adhesive. However, at least the force-transmitting surfaces are curved concavely or convexly everywhere, and the force-transmitting surfaces are arranged on the surface of the convex hull of the corresponding structure or, in the case of the inner structure, of the inner bore surrounded by the inner structure.

Preferably, the force-transmitting surfaces make up substantially the entire circumference (i.e., the possible other structures constitute only a small portion of the area of, for example, a maximum of 20%). They are concave or convexly curved and free of straight or convex or concave partial surfaces. The force-transmitting surfaces preferably account for at least 70%, at least 80%) or at least 85% of the total surface in the area of the screw-in and / or anti-rotation structure.

In contrast to the prior art, so the Eindreh- and / or anti-rotation structure has no transitions between concave and convex surfaces and no straight sections. It has been shown that the continuous concave or convex curvature allows a very balanced load distribution and is also advantageous in manufacturing.

The concave or convex shape, in addition to the aforementioned uniform distribution of loads when applying a torque also has the advantage that it is particularly suitable for the production of abrasive machining process.

According to a feature of embodiments, the surface of the screw-in and / or anti-rotation structure consists of concave or convex radii (i.e., circular arc in section perpendicular to an implant axis), which preferably connect tangentially to one another.

According to a particularly preferred embodiment, the inner or outer structure (generally in a section perpendicular to the axis) is based on the shape of a Gleichdicks. A "cube of equal width" is a closed curve of constant width. The width is defined as the distance between two parallel lines which touch the curve on opposite sides. The trivial form of the dagger - namely the circular shape - is excluded here, as it does not allow transmission of torque.

From the above definition of the same dic also follows directly the property that a constant thickness can always be enclosed by a tangential square and at a rotation within this square always touches all four sides tangentially.

The suitability of the form concerning the uniform distribution of the loads when applying a torque and concerning the production of abrasive machining processes is particularly pronounced in the same-thick shape. For example, the width as a distance between a support and a machining tool is a particularly easy-to-control size.

Consequently, according to a further aspect of the invention, the implant, in addition to the distal, endosseous region, has an implantable state of proximally accessible insertion and / or anti-rotation structure (inner or outer structure), which in a section perpendicular to an axis along a Circumferential line has essentially the shape of a DC. Differing from the equal-thickness form may be furrows, which are not force-transmitting and which preferably make up not more than 20% circumferential line. In particular, the convex hull of the inner bore surrounded by the inner structure or the convex hull of the outer structure in the section perpendicular to the axis is (substantially) a same thickness.

Particularly preferred are regular, i. with respect to axial rotation about a symmetry angle symmetrical shapes, in particular regular DC dicks. (Reuleaux triangle, Reuleaux polygon - or its variant without a corner, in which the corner is replaced by a circular arc section). Such regular shapes have the advantage that the insertion tool and / or the body part can be applied in different orientations according to the respective angle division.

Regular dicks are based on regular polygons with an odd number of vertices, i. on an equilateral triangle, a regular pentagon, heptagon, etc. The larger the number of corners of a polygons underlying the regular dic-do, the smaller the distance between the circumference and the inscribed circle. The bigger this difference is. the greater the torque that can be transmitted through the structure. From this point of view, a Reuleaux triangle (in the variant without corners) is a particularly advantageous form. Nevertheless, depending on the application, it may also be favorable to use a Reuleaux pentagon or Reuleaux heptagon, in particular in applications in which an application of the screwing-in tool / mounting part in various orientations is desired.

Equally particularly preferred are equally thick shapes in which circular arc-shaped sections of different radii complement the mentioned contour, wherein at transitions between the arcuate sections of different radii, the tangents have a steady course (the tangent infinitesimal right of the transition point is equal to the tangent infinitesimal to the left of the transition point). Variants of Reuleaux polygons without corners and equally thick variants based on irregular polygons are such forms.

The screw-in and / or anti-rotation structure may be cylindrical (i.e., translationally symmetrical along the axis) or conical (i.e., steadily decreasing or enlarging in area while maintaining the shape of the perimeter as a function of axial position). There are also other embodiments conceivable, for example. In a section parallel to the axis slightly convex or slightly concave shapes.

In addition to the screw-in and / or anti-rotation structure, further structures may be present in a manner known per se, for example an anchoring section distal to the screw-in and / or anti-rotation structure. Such may have a fastening structure, in particular a thread, or a ribbing or the like for adhesive.

Likewise provided by the invention is an implant system which, in addition to an implant of the type described above, also has an abutment part (abutment, crown to be applied directly to the implant, bridge, prosthesis, cap, etc.), which is provided for direct attachment to the implant is and has a lot with a fitting structure, which cooperates with the screw-in and / or Verdrehsicherangsstruktur the implant to prevent rotation of the attached body part relative to the implant.

The invention further relates to a kit with at least one implant, a screwing-adapted thereto which cooperates with the Eindreh- and / or Verdrehsicherangsstruktur and optionally with at least one body part, which is intended for immediate attachment to the implant and a lot with a Having structure, which also cooperates with the screw-in and / or Verdrehsicherangsstruktur the implant to prevent rotation of the attached body part relative to the implant.

The implant system and / or kit may be in a sterile package.

Embodiments of the invention will be explained in more detail with reference to figures. The figures are not to scale. In the figures, like reference characters designate like or analogous elements. Show it: <tb> - Fig. 1a-1c <sep> an implant, an abutment of a first implant system and a screwing tool for: FIGS. 2 and 3 each show a view of the implant and of the first implant system in the assembled state, FIG. Fig. 4 <sep> is a sectional view of the first implant system in the assembled state; FIG. 5 shows a second implant system in the assembled state, wherein the implant is shown partially cut away; FIG. <tb> - Figures 6 and 7 <sep> constructions of equal dicks, FIG. 8 is a view of an implant of another implant system; and FIG <tb> - Fig. 9 <sep> an irregular equal thickness.

1a, 1b and 1c show a kit with an implant 1, an abutment 2 adapted thereto and a screwing-in tool 3. The implant 1 according to FIG. 1b has an endosseous area with a thread 11 and a proximal thread-free section widening in the proximal direction 12 on. Towards the distal (apical) end, the enossal area is slightly conically tapered and has a ridge 13 to facilitate insertion of the implant. Open to the proximal side is an axially extending bore 14 with a distal, substantially cylindrical and in the view of Fig. 1b barely visible anchoring portion and a proximal portion which is contoured to form a screw-in and / or anti-rotation structure 16. The inner contour of the screw-in and / or anti-rotation structure is concave without straight surfaces. In a section perpendicular to the axis, the contour is in the form of a delta-based dic- tion.

The abutment 2 according to FIG. 1ahat has a post 21 for the attachment of a tertiary part to the proximal (coronal) side. As shown, the post can run axially and cylindrically symmetrically, or else - as is known, it can be angled and / or flattened or have another structure deviating from the cylindric symmetry. Towards the distal end, the abutment has an outer structure adapted to the inner structure (bore) of the implant. In addition to a distal, substantially conical anchoring region 23, this also includes a fitting structure 26, which is matched to the screw-in and / or anti-rotation structure, so that a mutual security against rotation arises. The anchoring area has a plurality of circumferentially extending grooves 24 which act as distribution channels for the adhesive with which the abutment is attached to the implant. The furrows also increase the attachment effect of the adhesive. The axial sections 25 between the grooves may be slightly flattened or also axially-grooved and act as axial distribution channels for the adhesive.

In Fig. 1c is still a driving tool 3 is shown. The insertion tool as a whole has an approximately cylindrical base body. In a distal region-towards its distal end-it has a fitting structure 36 which is likewise adapted for engagement in the screw-in and / or anti-rotation structure 16. The insertion tool-fitting structure 36 thus corresponds essentially to the fitting structure 26 of the abutment. However, a part of the screwing tool which adjoins the fitting structure 36 distally and engages in the anchoring section is optional and not necessary. When screwing tool 3 shown in the figure, such a lot does not exist. The axial extent of the insertion tool-fitting structure 36 is also smaller in the illustrated embodiment than the corresponding axial extent of the fitting structure 26 of the abutment and the screw-in and / or anti-rotation structure 16 of the implant. Further, an O-ring 37 is positioned so that it also engages in the screw-in and / or anti-rotation structure 16, thereby elastically deformed and can serve as a support of the implant during transfer from the package into the mouth of the patient.

After proximal, the screwing-in tool also has an integrally formed holding structure 38. In the illustrated embodiment, this corresponds to an external hexagon and serves to attach a standardized tool for applying a torque to the screwing-in third

Fig. 2 shows the implant 1 in a plan view (a view from the proximal side). It can be seen particularly well that the screw-in and / or anti-rotation structure 16 has the form of a regular, derived from the Reuleaux triangle dynasty. FIG. 3 shows a corresponding plan view of the implant with fitted abutment 2.

The anchoring section and according to the anchoring area 23 of the abutment 2 are here slightly conical with a conicity of between 2 ° and 5 °. The distal end surface 28 of the abutment optionally forms a stop at the bottom of the axial bore. Alternatively or additionally, the shoulder between anchoring portion and Eindreh- and / or anti-rotation structure and / or - if present - the cone itself form a stop.

There are also cylindrical or other running anchoring sections / anchoring areas conceivable, and it is also not in section perpendicular to the axis 7 not round anchoring sections / anchoring areas conceivable.

Implant 1 and abutment 2 form a common outer shoulder 15, which is proximal to the endosseous region and on which the tertiary element can be supported. The angle of the outer shoulder 15 to the implant axis 7 is between 45 ° and 75 °, in particular between 52 ° and 70 °. The transition between the implant and the abutment is preferably in the upper region of the shoulder (ie, the proportion of the shoulder formed by the implant is greater than the proportion formed by the abutment so that the transition is accessible when the abutment is attached after subgingival healing of the implant ,

Firstly, the implant system according to FIG. 5 differs from the implant system according to FIGS. 1-4 in that the screw-in and / or anti-rotation structure 16/26 does not have a triangle but a pentagon as its base, i. it has no threefold symmetry but a pentad symmetry. Another difference lies in the anchoring region 23 of the abutment, in which the axial grooves 25 are more pronounced and widen and deepen distally. In addition, axial grooves 29 for excess adhesive are also present in the region of the fitting structure 26 of the abutment. In the region of these grooves, the fitting structure 26 deviates from the purely convex shape. However, the screw-in and / or anti-rotation structure 16 of the implant is completely convex and thus free of elements engaging in the grooves 29, so that the grooves do not serve to transmit torque and are not part of the screw-in and / or anti-rotation structure. In principle, it would also be possible to provide corresponding grooves on the implant, in which case the abutment and the screwing tool would be free of elements engaging in such grooves.

Fig. 6 shows schematically a regular constant thickness 41 based on an equilateral triangle as the base polygon 42. It can be constructed geometrically by circular arc sections. The centers M of the corresponding circular arcs are the vertices of the triangle; the transitions between the circular arc sections are at the same time the intersection points with the extended triangular sides. The vertices serve as centers for the nearest strongly curved section (small radius) and the opposite weakly curved section (large radius). In the area of the transitions between the circular arc sections, the tangents have a continuous course, i. The circular arc sections connect tangentially to each other.

Fig. 7 shows a regular uniform thickness 41 with a regular pentagon as the base polygon 42. The centers M of the curved sections are the intersections of the extended polygon sides. Again, the centers serve as centers for the nearest strongly curved section (small radius) and the opposite weakly curved section (large radius). Here too, in the region of the transitions between the circular arc sections, the circular arc sections tangentially adjoin one another.

In the choice of sizing can proceed as follows. At an external nominal diameter of the implant (for example 5 mm) given by the circumstances, first the diameter of the circumference is determined, since this should not exceed a certain value due to the minimum wall thickness (for example Z) = 4.25 mm). For a given pitch (eg 72 ° for a pentagon as the base polygon), the small radius can be chosen arbitrarily. For example, it can be adapted to a tool diameter of a tool with which the same thickness is to be processed. For a small radius of 0.9 mm, in the present example, a pentagon as the base polygon and the condition of continuity at the transition between circular arc sections give a value of 3.23 mm, which is a uniform diameter (a "thickness") of 4.13 mm results.

FIG. 8 shows, in a view corresponding to FIG. 2, an implant 1 with a regular uniform thickness based on a heptagon. Finally, FIG. 9 shows an example of a constant thickness 41 with an irregular base polygon 42. The midpoints M again correspond to the intersections between the elongated polygon sides, and at the same time serve as centers for the nearest highly curved portion (small radius) and the opposite weakly curved portion (large radius). Again, in the area of the transitions between the circular arc sections, the circular arc sections tangentially adjoin one another; the construction is analogous to FIG. 7.

The course of the screw-in and / or anti-rotation structure 16 and the corresponding fitting structure 26 in the axial direction (the depth profile) may be cylindrical, conical convex, concave, S-shaped, etc. Even a stepped course is not excluded.

Many other variants are possible.

While, for example, the described embodiments relate to two-part implant systems with an adhesive connection between implant and abutment, the inventive procedure can be easily transferred to other implant systems. Thus, screwed implant abutment connections can also have a screw-in and / or anti-rotation structure of the type described above with an inner structure on the implant and a corresponding outer structure on the abutment; In general, then in the bore of the implant distal of the screw-in and / or anti-rotation structure have an internal thread for the screw with which the abutment is attached to the implant. An application to one-piece implants is also conceivable, in which case the screw-in structure of the implant can also be an external structure that interacts with a corresponding internal structure of the screw-in tool. Furthermore, the approaches of the invention are particularly suitable for implants with a screwed into the jaw bone thread, but they are also suitable for implants for threadless anchoring. In such a case, the screw-in and / or anti-rotation structure will serve in particular for the rotation between the implant and abutment and usually serve for the transmission of less large torques.

Claims (12)

1. implant (1) with a distal, endosseous area for implantation in a jawbone and in the implanted state of proximally accessible Eindreh- and / or anti-rotation structure (16), characterized in that the screw-in and / or anti-rotation structure (16) in is a section perpendicular to an axis along a circumferential line substantially everywhere concave or convexly curved everywhere. 2. Implant according to one of the preceding claims, characterized in that the surface of the screw-in and / or anti-rotation structure in the section perpendicular to the implant axis consists of concave or convex circular arc sections. 3. Implant according to claim 2, characterized in that the circular arc sections connect tangentially to each other. 4. Implant according to one of the preceding claims, characterized in that the screw-in and / or anti-rotation structure (16) in the section perpendicular to the axis has the shape of a dic else. 5. Implant according to one of the preceding claims, characterized in that the screw-in and / or anti-rotation structure (16) is regular in that it is symmetrical about a rotation about the axis about a symmetry angle. 6. Implant according to one of the preceding claims, characterized in that the screw-in and / or anti-rotation structure (16) is cylindrical or conical. 7. Implant according to one of the preceding claims, characterized in that the implant is designed for subgingival healing, and that the screw-in and / or anti-rotation structure (16) is an internal structure. 8. Implant according to claim 7, characterized in that the screw-in and / or anti-rotation structure (16) is formed by a surface of a proximally accessible bore and that the bore distal of the screw-in and / or anti-rotation structure (16) has an anchoring portion through which an abutment (2) can be anchored to the implant. 9. Implant according to one of claims 1 to 6, characterized in that the implant is in one piece. 10. implant system, comprising an implant (1) according to one of the preceding claims and a mounting part (2) which is designed for direct attachment to the implant (1) and a lot with a fitting structure (26) which with the Eindreh- and or anti-rotation structure (16) of the implant cooperates to prevent rotation of the attached body part (2) relative to the implant (1). 11. kit, comprising an implant according to one of claims 1 to 9 or an implant system according to claim 10, wherein the implant has a thread (11) for screwing into the jaw bone, and a screwing tool (3) with a screwing passport structure (36) , which cooperates with the screw-in and / or anti-rotation structure (16) of the implant in such a way that torque can be exerted on the implant (1) by the screwing-in tool (3) during screwing-in. 12. Kit according to claim 11, wherein the insertion tool-fitting structure (36) in a distal region of the screwing tool (3) is present, and wherein in a proximal portion of Eindrehwerzeugs additionally a holding structure (38) for applying a further tool is present.