Dental Implant Having Different Degrees of Surface Roughness

Abstract

The invention relates to a dental implant having various regions with different degrees of surface roughness.

Claims

1. A dental implant consisting completely or partially of ceramics comprising an enossal region (1) for ingrowth by a jaw bone, an abutment (3) for receiving a prosthetic care article, and an implant neck (2) arranged between said enossal region (1) and said abutment (3) for adhesion of gingival cells, characterized in that said enossal region (1), said implant neck (2) and said abutment (3) have respectively different average degrees of surface roughness R.sub.a as measured according to DIN EN ISO 4287, in which said enossal region (1) has an average surface roughness R.sub.a(E) of from 1.2 to 2.0 μm; said implant neck (2) has an average surface roughness R.sub.a(H) of from 0.04 to 0.2 μm; and said abutment has an average surface roughness R.sub.a(A) of from 0.25 to 0.7 μm.

2. The dental implant according to claim 1, characterized in that said enossal region (1) has a thread.

3. The dental implant according to claim 1, characterized in that said enossal region (1) has an average surface roughness R.sub.a(E) of from 1.2 to 1.8 μm, especially from 1.4 to 1.6 μm, as measured according to DIN EN ISO 4287.

4. The dental implant according to claim 1, characterized in that said dental implant has a pin-shaped design, wherein the maximum diameter of the implant neck (2) is equal to or smaller than the maximum diameter of the enossal region (1).

5. The dental implant according to claim 1, characterized in that said implant neck (2) has an average surface roughness R.sub.a(H) of from 0.06 to 0.16 μm, specifically from 0.08 to 0.12 μm, or up to 0.10 μm, as measured according to DIN EN ISO 4287.

6. The dental implant according to claim 1, characterized in that said implant neck (2) has a conical section (4) in which the diameter preferably becomes smaller from the side facing the abutment (3) to the side facing the enossal region (1).

7. The dental implant according to claim 1, characterized in that said implant neck (2) has a conical section (4) and a horizontal circumferential recess (5), especially a horizontal circumferential groove.

8. The dental implant according to claim 1, characterized in that said implant neck (2) has a horizontal circumferential groove (5) that directly borders the enossal region (1).

9. The dental implant according to claim 7, characterized in that said implant neck (2) has a horizontal circumferential groove (5) that is arranged between said enossal region (1) and said conical section (4) of the implant neck.

10. The dental implant according to claim 1, characterized in that said abutment (3) has one or more recesses.

11. The dental implant according to claim 1, characterized in that said abutment (3) has one or more microgrooves.

12. The dental implant according to claim 1, characterized in that said abutment (3) has an average surface roughness R.sub.a(A) of from 0.3 to 0.6 μm, specifically from 0.3 to 0.5 μm, as measured according to DIN EN ISO 4287.

13. The dental implant according to claim 1, characterized in that said dental implant is integrally formed.

14. The dental implant according to claim 1, characterized in that said dental implant is completely or partially made of an oxide ceramic comprising one or more oxides of the metals selected from aluminum, zirconium, yttrium, cerium, hafnium, and magnesium.

15. The dental implant according to claim 1, characterized in that said ceramic is a glass ceramic.

16. The dental implant according to claim 1, characterized in that said enossal region has a microstructure with an average pore size of 2 μm or less, preferably from 0.5 μm to 1 μm.

17. The dental implant according to claim 1, characterized in that said abutment has a height of from 2.5 to 5.5 mm.

18. The dental implant according to claim 1, characterized in that the ratio of the average surface roughness values of the abutment to the enossal region, R.sub.a(A)/R.sub.a(E), is from 1:8 to 1:15, preferably from 1:5 to 1:3.5.

Description

[0036] Details and advantages of the present invention are illustrated further by means of the following drawings, which are by no means to be construed as limiting the concept of the invention.

[0037] The ceramic dental implants of the present invention show advantages over metallic implants not only in terms of their aesthetic appearance and strength, but also in terms of the adhesion of bone cells and the spreading of gingival fibroblasts.

[0038] FIG. 1 shows, by way of example, a schematic representation of a ceramic dental implant according to the invention (based on an yttria-stabilized zirconium oxide) comprising an enossal region 1 (the part of the dental implant that serves for anchoring within the jaw), an abutment 3 and implant neck 2. There is further represented a conical section 4, which forms the implant neck 2, and a horizontal peripheral groove 5, which is provided below the conical section 4 and which is followed by the thread of the enossal region.

[0039] FIG. 2 shows a scanning electron micrograph of the surface of the enossal region of the dental implant according to the invention, wherein the microstructure of the macroscopically rough surface is clearly recognizable. The regions that appear darker in the photograph are located deeper and form a physical retention of the implant directly after the implant has been inserted into the bone. Without being bound by theory, it is assumed that the spongy bone displaced when the implant was inserted occupies this macroroughness and thus causes the improved primary strength of the implant according to the invention. The high acceptance of the bone cells observed is explained by the microroughness of the surface and creates the precondition of a gap-free ingrowth of the bone into the dental implant according to the invention.

[0040] FIG. 3 shows bone cells adhered to the surface of the enossal region of a dental implant according to the invention. The two-dimensional adhesion/expansion of the cells is clearly recognizable.

[0041] FIG. 4 shows the spreading of gingival fibroblasts after 24 hours on the implant neck of a dental implant according to the invention.