WO2005112816A1

WO2005112816A1 - Tooth implant

Info

Publication number: WO2005112816A1
Application number: PCT/EP2004/004228
Authority: WO
Inventors: Michael Krumsiek; Stefan Neumeyer
Original assignee: Gebr. Brasseler Gmbh & Co. Kg
Priority date: 2004-04-21
Filing date: 2004-04-21
Publication date: 2005-12-01

Abstract

The invention relates to a tooth implant having a threaded enossal zone (1), a center zone (2) and a coronal zone (3). The tooth implant is characterized in that the enossal zone (1) comprises differently threaded sections.

Description

dental implant

The invention relates to a dental implant according to the preamble of the main claim.

More specifically, the invention relates to a dental implant with a threaded endosseous area, a central area and a coronal area.

Dental implants are known from the prior art in a wide variety of configurations. Examples of this are shown in EP 0 388 576 B1 or EP 0 668 751 B1.

In general, it is necessary for dental implants to be designed so that they can be optimally anchored in the patient's jaw. The known dental implants are made in one piece or in several parts, they mostly consist of biocompatible materials, such as titanium or titanium alloys, aluminum or zirconium oxide ceramics, or also of solid biocompatible plastics.

The invention has for its object to provide a dental implant which has a high degree of anchoring strength with a simple structure and can be used with a minimal amount of work.

According to the invention the object is achieved by the combination of features of the main claim, the subclaims show further advantageous embodiments of the invention.

Furthermore, the invention relates to a dental drill for use in the dental implant according to the invention. In detail, the invention therefore provides that the endosseous area comprises different threaded sections. It is particularly advantageous if three different thread sections are provided. These can preferably each extend over a third of the length of the endosseous area.

The dental implant according to the invention is characterized by a number of considerable advantages. Due to the design of the endosseous area, the implant is suitable for immediate implantation and for immediate loading, since the individual, different thread sections each perform different tasks and accordingly anchor the tooth implant in the bone in different ways. The tooth implant according to the invention thus creates a tooth-shaped endosseous design which enables immediate implantation. The immediate loading results in high primary stability. The limited micro-mobility enables immediate loading.

It is particularly advantageously provided that an apical thread section has a high thread depth with steep flanks, that a central thread section is provided with a conical core and a cylindrical outer diameter envelope curve, and that a coronal thread section has a small thread depth and is designed in the manner of a trapezoidal thread ,

The central area of the thread compresses the jawbone in the horizontal and vertical directions. This results in a high primary stability for the required immediate loading in the middle as well as in the coronal thread section or thread area. The design of the threaded sections leads to a precise Form fit in the contact area between the implant and the bone.

The endosseous area designed according to the invention is cylindrically stepped by the three different threaded sections and thus simulates the cavity in the jaw after tooth loss. The thread pitch is preferably 0.6 mm.

The individual thread sections are shaped according to the bone quality found in the jaw. A large thread depth, preferably 0.25 to 0.4 mm, is provided in the apical thread section for increased retention in the cancellous bone.

The central thread section has a slightly tapered thread depth. This results in the aforementioned compression in the horizontal direction when screwing in. The thread flanks have an increasing surface area in cross section. This leads to a compression of the bone in the vertical direction when screwing in. The thread depth is approx. 60 to 80% of the depth of the thread in the apical thread section.

The coronal thread section has a smaller thread depth, which leads to a form fit with the solid bone. The thread depth is approx. 30 to 50% of the depth of the thread in the apical thread section. This results in increased primary stability, which contributes to a reduced micro-mobility of the dental implant. The flank angle of the thread sections can be between 50 ° and 70 °, it can vary between the individual thread sections. The transitions from at least two threaded sections (preferably from the apical threaded section to the central thread section) are tapered in a range of 0.3 to 0.8 mm in length.

The outside diameter of the apical thread section is smaller than - as will be described below - the instrument diameter of the implant bed drill in the central area thereof. This ensures centering, and the implant is guided accordingly when it is screwed in.

The endosseous area of the dental implant is preferably conditioned in such a way that there is a possibility of micro and macro retention. This can be done by blasting with A1 ₂ 0 ₃ to produce the macro roughness and / or by chemical etching to produce the micro roughness. In addition, a coating that promotes osseointegration, for example calcium phosphate, can be applied in this area.

The neck area of the dental implant should correspond to the natural shape of the tooth neck. The diameter of the implant neck should increase conically in the course from apical to coronal. According to the invention, it is further provided that the top view does not result in a rotationally symmetrical shape, but rather an elliptical shape.

This area of the dental implant can be provided with a biocompatible non-stick coating.

The advantage here is that after the abutment and implant have been glued, adhering composite residues can easily be removed. It is particularly advantageous if the tooth implant is provided in the neck area with a mounted gingival cuff which protects the gingiva from the not yet hardened composite during the bonding of the implant and abutment.

It is further provided according to the invention that the garland-shaped bone-gingiva course is formed by a multi-start thread parallel to the key surfaces on the retention pin in the region of the implant neck. When the implant is screwed in, the bone is structured by the outward thread in such a way that force transmission from the implant to the bone is possible in an optimal manner. This reduces bone resorption after implantation.

It is particularly advantageous here that the retention option is only available where it is meaningful and required due to the jawbone profile. The external toothing (thread) also increases the primary stability. In the Pallatinal / Labial view, a finely structured surface is provided. This can be machine-turned or polished, for example. This significantly inhibits the colonization of bacteria.

An essential aspect according to the invention thus lies in the elliptical neck region and in the girl-shaped course of the transition from the implant neck to the implant shoulder.

With regard to the shoulder area of the implant, it is particularly advantageous if it has a horizontal contact surface. This brings advantages when applying force from the abutment to the implant. Since the ceramic abut- ent is much more resilient to pressure than to tension, there is a significant reduction in the risk of fractures.

The chamfer provided according to the invention at the transition from the implant neck to the implant shoulder has two advantageous functions. On the one hand, the chamfer can be used to create the garland, an angle of preferably 40 ° to 70 ° being provided. Furthermore, the conical shape results in a smaller adhesive gap width in contrast to a horizontal joining surface with the same contact pressure.

With regard to the retention pin according to the invention, it is provided that it runs conically. When the abutment is glued on, it is possible to grind it to compensate for the divergence between the ideal and actual alignment of the implant axis.

According to the invention, the retention pin preferably has at least one driver surface for transmitting the screw-in torque. Furthermore, a groove can be provided as a retention option for a tool, for example a screw-in key.

According to the invention, the implant can be designed in one part or two parts. In the case of a two-part design, the implant can be provided with an internal bore and an internal thread for receiving a screw-in abutment (concealed healing). A suitable abutment can be screwed in or glued in.

Furthermore, it is possible according to the invention to provide the implant with a factory-made, preferably ceramic, grindable abutment. At the top of the retention spigot, a continuous instrument shaft is inserted possible to rotate the implant. This instrument shaft or handling attachment can be provided with an angled shaft end for mechanical insertion or with an angled shaft end and a screw-in adapter for manual insertion.

According to the invention, it is also possible to provide a handling attachment on the abutment which can be removed subsequently. This has the advantage that an adhesive bond is possible in the factory and the bonding can take place under optimized conditions.

With the gingival cuff provided according to the invention, it proves to be particularly advantageous if it consists of a biocompatible polymer, for example of thermoplastics or elastomers or of silicone. The gingival cuff can be slipped onto the implant neck at the factory before the implant is sterilized.

In the embodiment provided according to the invention, the gingival cuff widens in a funnel shape in cross section towards the coronal area.

The gingival cuff protects the implant neck from contamination and moisture during implantation. Furthermore, the composite that has not yet polymerized cannot reach the wound area. After the ceramic abutment has been inserted and glued, the gingival sleeve can be easily removed.

In the embodiment of the abutment according to the invention, it is provided that it consists of a heavy-duty, tooth-colored material, preferably of ceramic. Here, a core made of a densely sintered ceramic and an outer body made of a porous ceramic may be provided. The latter is easier to grind.

The design of the abutment can be modeled on the teeth to be replaced, for example an anterior tooth or premolars / molars. According to the invention, this results in a very good fit to the retention spigot or the implant shoulder. According to the invention, the abutments are provided on the outer surfaces with an allowance which enables the abutment to be machined or ground after insertion.

According to the invention, it is also possible to manufacture the abutments from non-tooth-colored material, for example from burn-out plastic, in order to produce cast abutments. It is also possible to provide magnets, O-rings, push-button anchors or bar anchors on the tooth implant according to the invention in order to secure the final restoration.

According to the invention, the abutment can be glued or screwed to the implant.

With regard to the design of the dental drill or the instrument which is to be used to form the threaded hole in the bone, it is particularly advantageous if an application aid is provided which simulates the abutment to be subsequently applied in shape and position. This means that the position of the implant (drilling depth, axis alignment) can be visualized as soon as the pilot hole is created. The invention is described below using exemplary embodiments in conjunction with the drawing. It shows:

1 is a schematic side view of a first embodiment of the dental implant according to the invention,

2 is an enlarged partial view of the apical threaded portion,

3 is an enlarged detail view of the central threaded section,

4 is an enlarged partial view of the coronal thread section,

5 and 6 detailed representations of the central threaded portion shown in Fig. 3,

7 to 13 workflows for inserting the dental implant according to the invention,

14 is a simplified side view of a dental drill according to the invention for use in a dental implant of the type described above,

15 is an illustration of the dental implant according to the invention, similar to FIG. 1, with a gingival cuff attached,

16 shows the coronal region with the abutment attached,

17 shows a detailed representation of the retention pin of the coronal area, 18 shows an illustration, analogous to FIG. 1, to illustrate the garland-shaped course in the region of the central region of the dental implant,

19 is an illustration of the dental implant, analogous to FIGS. 1 and 18, with an illustration of the loads occurring,

20 and 21 representations of the dental implant with embodiments of handling approaches, and

22 and 23 two-part configurations of the dental implant according to the invention, analogous to the illustration in FIG. 1.

1 shows a side view of a dental implant according to the invention with an endosseous area 1, a middle area 2 and a coronal area 3. The endosseous area comprises an apical thread section 4, a middle thread section 5 and a coronal thread section 6. These each extend essentially over a third of the total length of the endosseous area.

The middle region 2 is then formed on the endosseous region. This comprises a thread 10 of a conically widening neck region 9 as well as an adjoining implant shoulder 11, which comprises a contact surface 12 oriented perpendicular to the longitudinal axis of the dental implant.

The coronal region 3 comprises a retention pin 13 which, as will be described below in connection with FIG. 17, comprises a conical base region 15 and an adjoining, conically beginning head region 16. A part of the apical thread section 4 is shown enlarged in FIG. 2. This includes a thread with a high thread depth for increased retention in cancellous bone.

The adjoining central threaded section 5, as shown in FIG. 5, is provided with a conical core which is formed by the base surfaces of the threaded grooves 8. The thread base is therefore conical. This results in the increasing radial loading of the bone indicated by the arrows in FIG. 5 when the dental implant is screwed in.

4 the coronal thread section is shown. It includes a small thread height with a relatively large width of the thread grooves.

FIG. 6 further shows that the width of the thread grooves is increasingly reduced, two regions XI and X3 are shown, from which the decreasing width results. This reduction in width results not only from a reduction in the width of the thread grooves or their base regions, but also from an increase in the width of the thread webs 7. This results in additional anchoring and force introduction through the thread flanks, as shown in FIG. 6 the diagonal arrows is shown.

7 to 13 show the different treatment processes that are possible in one session. 7 and 8, the introduction of a pilot hole is shown. FIG. 9 shows the insertion of an implant bed bore, the stepped contour of the inventive see threaded sections is formed. Subsequently, as shown in Fig. 10, the thread is cut. 11, the dental implant according to the invention is subsequently screwed in with the gingival cuff. 12 shows the adhesive attachment of the ceramic abutment. The treatment step of Fig. 13 shows that the gingival cuff has been removed. The ceramic abutment is ground, the composite residues are removed. An impression is then taken and a temporary crown made of temporary composite is created. This temporary composite serves as a shock absorber during the transfer of the chewing forces into the implant and thus into the jaw (see Gerd KH case code: Dental implantology, science and practice, Quintessenz Bibliothek 1986). The final restoration is then manufactured and integrated. The result is that the insertion of the dental implant and provisional restoration can take place within one session. This results in a very substantial relief for the dentist.

FIG. 14 shows a schematic lateral illustration of the implant drill shown for example in FIG. 9. This comprises a customary shaft 21 and a working area 22, the gradation and dimensioning of which corresponds to the endosseous area of the dental implant, as described in connection with FIG. 9. According to the invention, an application aid 23 is additionally applied, which can be detached from the shaft 21 and indicates to the dentist the shape and positioning of the ceramic abutment to be subsequently applied. The position of the final restoration can already be seen during the preparation.

The gingival cuff 14 already indicated in FIGS. 11 and 12 is again shown in an enlarged representation in FIG. 15 shown. The gingival cuff 14 consists of a biocompatible elastomer, for example of silicone. It is assembled at the factory and serves to support the adhesive attachment of the ceramic abutment. It protects against contamination and moisture.

16 illustrates the two-layer structure of the ceramic abutment 17 provided according to the invention. In the embodiment shown, this comprises a core 18 made of a densely sintered ceramic and an outer body 19 made of a porous sintered ceramic. The two ceramics are glued together using a composite. The porous sintered ceramic is easier to grind and process, while the densely sintered ceramic brings advantages in applying the forces to the crown of the restoration, while the densely sintered ceramic transfers the forces from the crown to the implant.

As shown in FIG. 17, the retention pin 13 is conical overall. It comprises a conicity in its base region 15, which is represented by "Z" in FIG. 17. Following the base area, a taper is provided on the head area, which is illustrated in FIG. 17 by "X". The taper X is greater than the taper Z. Subsequent to the conical region of the head region 16, this is rounded off, as can be seen from FIG. 17.

In FIG. 18, in addition to the illustration in FIG. 1, the configuration of the implant shark is illustrated. This includes the thread 10 already mentioned, which is designed as a multi-start, outward thread in the aproximal area. This serves to avoid bone resorption due to an early loading of the bone along the Bone gingiva course. The arrows in FIG. 18 show the garland-shaped course of the roughened region of the implant neck. As mentioned, the thread 10 is only provided laterally at the intermediate areas to the neighboring teeth.

19 shows the application of force from the abutment to the implant (see arrows F). Furthermore, the formation of the garland of the implant neck is shown by the four additional arrows. Overall, this configuration results in a smaller adhesive gap width with the same contact pressure, compared to the configurations known from the prior art.

20 and 21 show embodiments of the dental implant according to the invention, in which a grindable ceramic abutment 17 is already installed in the factory. This is provided with an additional handling approach 20, which can consist of a ceramic material (Fig. 20) or can be designed in the form of a metallic pin (Fig. 21). In both cases, the handling attachment 20 is provided with a chamfer and / or a groove in order to be able to screw the tooth implant in mechanically or manually. The handling approach 20 can be separated after the dental implant has been inserted.

Power transmission when screwing in mechanically: via the end of the angular shaft (surface) Power transmission when screwing in manually: via the end of the polygon

22 and 23 show embodiments according to the invention in which the dental implant is formed in two parts. The endosseous area 1 is provided with an end recess 24 into which an extension 25 is provided is integrally connected to the retention pin 13, can be used. The approach 25 can be screwed or glued.

As can be seen from FIG. 22, at least one of the threaded sections 4 to 6 of the endosseous region 1 has a groove 26 which extends in the axial direction. The depth of the groove is greater than the thread depth or thread height. A plurality of such grooves can preferably also be provided distributed around the circumference. The grooves each form a cut, so that the threaded sections 4 to 6 are each designed as self-tapping threads. One or more grooves can be provided on each of the threaded sections 4 to 6. For example, the grooves are offset by 120 ° to each other for each threaded section. The individual grooves or gates of the individual steps of the threaded sections 4 to 6 could also be offset from one another, for example by 60 °. As a result, the individual thread sections 4 to 6 are each self-tapping, so that an especially secure anchoring takes place.

The invention is not limited to the exemplary embodiments shown, but there are many possible modifications and modifications within the scope of the invention.

LIST OF REFERENCE NUMBERS

1 endosseous area

2 middle area

3 coronal area

4 apical thread section

5 middle thread section

6 coronal thread section

7 thread bars

8 thread grooves

9 neck area 0 thread 9 1 implant shoulder 2 contact surface 3 retention pin 4 gingival sleeve 5 base area 13 6 head area 13 7 abutment 8 core 9 outer body 0 handling approach 1 shaft 2 work area 3 application aid 4 recess 5 approach 6 groove

Claims

Claims 1-25

1. Dental implant with a threaded endosseous area (1), a middle area (2) and a coronal area (3), the endosseous area (1) comprising different thread sections, characterized in that the middle area (2) of the implant comprises a neck region (9) which increases conically from apical to coronal and which is provided with a multi-start thread (10).

2. Dental implant according to claim 1, characterized in that the thread (10) is formed laterally on the neck area (9) and extends in the inserted implant in the approximal area to the neighboring teeth.

3. Dental implant according to claim 1 or 2, characterized in that the neck region (9) is elliptical in cross section.

4. Dental implant according to one of claims 1 to 3, characterized in that the neck region (9) is provided with a non-stick coating.

5. Dental implant according to one of claims 1 to 4, characterized in that a transition from the neck region (9) to the implant shoulder is formed in a garland.

6. Dental implant according to claim 5, characterized in that a chamfer is provided at the transition from the neck region (9) to the implant shoulder (11).

7. Dental implant according to claim 5 or 6, characterized in that the implant shoulder (11) for one Longitudinal axis of the implant has a vertical, flat contact surface (12).

8. Dental implant according to one of claims 1 to 7, characterized in that three different threaded sections are provided.

9. Dental implant according to claim 8, characterized in that the three threaded sections each extend substantially over a third of the length of the endosseous area.

10. Dental implant according to one of claims 8 or 9, characterized in that an apical threaded section (4) has a high thread depth with steep flanks, that a central threaded section (5) is provided with a conical core and a cylindrical outer diameter envelope, and that a coronal thread section (6) has a small thread depth and is designed in the manner of a trapezoidal thread.

11. Dental implant according to claim 10, characterized in that the central threaded section (5) has a thread depth of 60 to 80% of the thread depth of the apical threaded section (4).

12. Dental implant according to one of claims 1 to 11, characterized in that the coronal thread section (6) has a thread depth of 30 to 50% of the thread depth of the apical thread section (4).

13. Dental implant according to one of claims 10 to 12, characterized in that the central threaded section (5) from the apical threaded section (4) to the coronal has thread section (6) with essentially the same pitch widening thread webs (7) and narrowing thread grooves (8).

14. Dental implant according to claim 13, characterized in that the central threaded section (5) comprises a conical body defined by the thread grooves (8).

15. Dental implant according to one of claims 10 to 13, characterized in that the outer diameter of the apical threaded section (4) is smaller than the outer diameter of the central (5) and the coronal (6) threaded section.

16. Dental implant according to one of claims 1 to 15, characterized in that the coronal region (3) comprises a conical retention pin (13).

17. Dental implant according to one of claims 1 to 16, characterized in that a detachable gingival sleeve (14) is arranged on the central region (2).

18. Dental implant according to one of claims 16 or 17, characterized in that the retention pin (13) is conical and has a lower conicity in its base region (15) and a greater conicity in its head region (16).

19. Dental implant according to one of claims 16 to 18, characterized in that a ceramic abutment (17) is applied to the retention pin (13).

20. Dental implant according to claim 19, characterized in that the abutment (17) comprises a core (18) made of densely sintered ceramic and an outer body made of porous sintered ceramic.

21. Dental implant according to one of claims 19 to 21, characterized in that a removable handling attachment (20) is attached to the retention pin (13).

22. Dental implant according to one of claims 1 to 21, characterized in that at least one of the threaded sections (4 to 6) of the endosseous region (1) is provided with at least one groove which forms a gate and extends at least over a partial range of the axial length.

23. Dental implant according to claim 22, characterized in that a plurality of grooves are provided, which are arranged offset to one another around the circumference.

24. Dental implant according to one of claims 22 or 23, characterized in that the depth of the groove is greater than the respective thread height or thread depth.

25. Dental drill for use in a dental implant according to one of claims 1 to 24, with a shaft (21) and a working area (22), the shape of which is adapted at least to the endosseous area (1) of the dental implant, characterized in that adjacent to the Working area (22) on the shaft (21) an application aid (23) in the form of the ceramic abutment (17) is arranged.