Implant for the jaw - Patent Review 4324550

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BACKGROUND OF THE INVENTION

The present invention concerns an implant for the jaw, comprising an implant body for cementless implantation, a bed made of a plastics material and an implant support.

Implants for the jaw having two stabilisator wings at the implant body and an implant support which is fastened into a bed of plastics material are known. The wings confer to the implant body a rotational stability but they make more difficult exact adjustment and adaptation of the body, after the incision for the wings have been made. Furthermore, because the rest of the walls are smooth the adherence of the jaw-bone to said implant does not always follow. The bed of plastics material is necessary for obtaining a certain flexibility of the tooth and a dampening of the chewing load and is made as cylindrical casing with an exterior and internal thread.

BRIEF SUMMARY OF THE INVENTION

The present invention seeks to overcome these disadvantages by constructing an implant which provides better anchorage of the bone allows better adjustment by the implantation and has a bed with a stronger grip.

BRIEF DESCRIPTION OF THE DRAWING

The invention will be described further, by way of example, with reference to the accompanying drawings, in which:

FIG. 1 is a side view of an implant according to the invention,

FIG. 2 is a sectional view in a larger scale of the implant of FIG. 1, and

FIG. 3 is a top plan view of the implant of FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT

In sectional view in FIG. 2 is shown the implant body 1, the bed 2 made of plastics material and the implant support 3. The implant body 1, in this example made of aluminum-oxide ceramics, has a frusto-conical form towards the bottom reaching into the bone and includes support ribs 4 which have the profile of a bone screw. These support ribs decrease the specific load of the implant on the jaw-bone and simulate, therefore the anchorage of the bone at the implant. The ribs also provide further for the primary optical tight agglomeration of implant surface and surrounding bone. The surface of the implant body comprises three notches 5, see FIG. 3, which each having a cutting edge 6, facilitating the screwing in of the implant body. The implant body comprises further a conical hole 7, tapered towards the bottom, for receiving the bed 2. The conical hole 7 has at its top end a shoulder 8 opening into a cylindrical hole, which has a greater diameter and an internal thread 9. At the top, the hole is formed into a cross-slot, for the insertion of an appropriate tool.

The external form of the bed matches the two holes in the implant body and comprises a frusto-conical part 10, tapered towards the bottom, a shoulder 11 having an external thread 12. The bed 2 has an internal thread 13 for the fixation of the implant support 3. The outer surface of the bed, adjacent to the implant body, has a structure 16 for enabling a greater flexibility and deformability because the bed contacts the internal surface of the implant body only punctually. This structure allows also a dampening of the chewing forces on the bone.

The implant support 3 comprises a threaded stud 14 and a square head 15, tapered towards the top, for receiving the suprastructure, that is the tooth. The outer diameter of the stud is dimensioned such that the conical part 10 of a bed is spread when the support is screwed in, causing the wedging of the bed with the implant body. The implant support is made of an appropriate metal or metal alloy.

As to materials for the implant body 1, besides the already mentioned aluminiumoxide ceramics, all materials usually employed in the human medecine, as for example titanium, a chrome-cobalt-molybdenum-alloy, carbon-fibres reinforced polyethylene, stainless steel or carbon, can be employed whereas the bed can be made of polyethylene.

For implanting, a core hole with an appropriate diameter is drilled first, then a thread is turned in and the implant body is screwed in during which the cutting edges 6 are reducing the force to be applied on the implant body. Upon cementless fastening of the implant body in this manner the plastics material bed and afterwards, thereafter the implant support are screwed in.

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