BLANK AND METHOD FOR THE MANUFACTURE OF AT LEAST ONE MOLDED PART

Abstract

The invention relates to a blank for the production of a molded body, in particular a dental reconstruction. The blank has a base and at least one region that emanates therefrom and projects above the base, from which at least a part of the molded body can be derived by working.

Claims

1. A blank for the production of a molded body, the blank comprising a base and at least one region that emanates therefrom and projects above the base, from which at least a part of the molded body is derived by mechanical working.

2. The blank according to claim 1, wherein the base has a disc geometry over which a plurality of regions project therefrom.

3. The blank according to claim 1, wherein the base includes at least two sides such that at least one region projects above the at least two sides of the base.

4. The blank according to claim 1, wherein the base is limited by one circumferential edge projecting above the base, which is manufactured integrally with the base or is an element connected to the base such as an adapter.

5. The blank according to claim 1, wherein the at least one region has a geometry selected from the group consisting of cuboid, cylindrical, conical and scythe shape.

6. The blank according to claim 1, wherein the base has a thickness B where B10 mm, in particular B5 mm.

7. The blank according to claim 6, wherein a ratio of thickness B of the base to a height H of the at least one region projecting above the base is 1:15B:H1:1.

8. The blank according to claim 1, wherein the base is of a material different from that of the at least one region, which is glued into one or more openings in the base or is injection molded from material of the base.

9. The blank according to claim 1, wherein the at least one region is a plurality of regions having different geometries project above the base.

10. The blank according to claim 9, wherein the plurality of regions have dimensions for the manufacture of one or more of a dental framework, a crown, a partial crown, a bridge, a dental arch, a cap, a veneer, an abutment, a pin construction, an inlay and/or an onlay.

11. The blank according to claim 1, wherein the blank and/or the at least one region includes a material selected from the group consisting of ceramic material, metallic material, an organic material, a composite material and a glass fiber-reinforced plastic.

12. The blank according to claim 1, wherein the base and the at least one region projecting above the base includes sections of different ceramic material compositions.

13. The blank according to claim 1, wherein the base and the at least one region projecting above the base includes sections of different material characteristics selected from the group consisting of strength, translucency, color, and fluorescence.

14. A method for the manufacture of at least one molded body that is a dental restoration, or part thereof comprising the step of: machining by material-removing of a region of a blank, the region projecting above a base, wherein the machining commences through removal of material from the circumferential surface of the region.

15. The method according to claim 14, wherein the machining step is carried out using a milling or grinding tool that has an axis of rotation and that at least at the start of the material removal there is a relative movement between the milling or grinding tool and the region transversely to the axis of rotation.

16. The method according to claim 14, further comprising the step of manufacturing the blank through pressing, casting, additive processes, forming and/or other mechanical manufacturing methods.

17. The method according to claim 14, further comprising machining the blank so that a plurality of regions emanate at a distance from one another through a section of the base.

18. The blank according to claim 1, wherein the base has a thickness B where 1.5 mmB4 mm.

19. The blank according to claim 18, wherein a ratio of thickness B of the base to a height H of the at least one region projecting above the base is 1:10B:H1:6.

20. The blank according to claim 11, wherein the ceramic material is selected from the group consisting of zirconium dioxide, glass ceramic, and feldspar ceramic, the metallic material is selected from the group consisting of titanium and CoCr alloy, and/or the organic material is a thermoplastic material.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figures:

[0024] FIG. 1 A top view of a first embodiment of a blank,

[0025] FIG. 2 A section along the line D-D in FIG. 1,

[0026] FIG. 3 The blank according to FIG. 1 viewed from the bottom,

[0027] FIG. 4 A top view of a second embodiment of a blank,

[0028] FIG. 5 A section along the line A-A in FIG. 4,

[0029] FIG. 6 The blank according to FIG. 4 viewed from the bottom,

[0030] FIG. 7 A further embodiment of a blank, and

[0031] FIG. 8 A section along the line A-A in FIG. 7.

DETAILED DESCRIPTION OF THE INVENTION

[0032] The teaching according to the invention is described in more detail with reference to the figures, on the basis of which molded bodies, in particular dental molded parts, can be produced in a material-saving manner from blanks, in particular through milling. At the same time this yields the advantage that the wear on the tool used for machining of the blank can be reduced.

[0033] The blanks can preferably comprise ceramic materials such as zirconium dioxide, glass ceramic, feldspar ceramic, to name just a few ceramic materials.

[0034] The blanks may in particular be of zirconium dioxide to which yttrium oxide, calcium oxide, magnesium oxide and/or cerium oxide is added, but in particular yttrium oxide stabilized zirconia.

[0035] Suitable materials also include metallic materials such as titanium or CoCr alloys.

[0036] The blanks may also be made from organic materials, optionally filled, in particular thermoplastic materials such as polymethylmethacrylate (PMMA) or polyetheretherketone (PEEK).

[0037] Composite materials or glass fiber-reinforced plastic are also possible.

[0038] Disc-shaped blanks are generally used to manufacture dental molded bodies/reconstructions through material-removing working. The dental restorations can be in the form of dental frameworks, crowns, partial crowns, bridges, caps, veneers, abutments, pin constructions, inlays and/or onlays or dental arches, but this is by no means an exhaustive list. A plurality of corresponding molded bodies may be obtained, depending on the diameter of the blanks.

[0039] Previously known blanks exhibit a uniform thickness across the regions from which the molded bodies are obtained through machining. A disadvantage here is that there are relatively high material losses since the material between the individual molded bodies is not utilized. A further particular disadvantage here is that the milling tool rotating about an axis of rotation and moving in the direction of the axis of rotation at least at the start of the processing of a molded part removes material from the blank with only a small part of the tool surface so that there is a high load on the tool. The wear is consequently relatively high.

[0040] All of these disadvantages are avoided with the blanks according to the invention.

[0041] FIGS. 1 to 3 thus show a first embodiment of a disc-shaped blank 10 that in the diagrams has a circular geometry, which has regions of different thickness.

[0042] Thus the blank 10 in principle comprises a base 12 and regions that emanate therefrom, indicated by way of example by the reference numbers 14, 16 and 18. In the exemplary embodiment the regions 14, 16, 18 do not just project above one side of the base 12, but rather extend on both sides, as clearly shown in the sectional view in FIG. 2. This, however, is not a required characteristic. Rather, the invention relates also to a blank wherein regions project only from one side of the base.

[0043] The height of the regions 14, 16, 18 is aligned with the molded bodies to be produced.

[0044] To obtain desired molded bodies from the regions 14, 16, 18, it is possible due to the space between the regions 14, 16, 18 that a machining tool acts from the side on the elevated regions 14, 16, 18, i.e., a relative movement to the elevation 14, 16, 18 substantially perpendicular to the axis of rotation of the tool is achieved. This possibility relates not just to the regions 14, 16, 18, that are arranged in the perimeter of the blank 10, but also to the regions surrounded by a plurality of projecting regions, as there is a distance between these, as can be seen in the sectional view of FIG. 2. A corresponding distance is indicated by way of example by the reference number 20.

[0045] In particular the invention provides for the elevated regions 14, 16, 18 emanating from the base to extend non-symmetrically on both sides of the base, so that without change to holders, that normally accommodate blanks with the usual milling machines, blanks according to the invention can be fixed in a processing machine. For this purpose a circumferential border 22 is provided in the exemplary embodiment which limits the blank 10 peripherally. In this example the edge 22 has an L-shaped cross-section and may be an integral part of the blank 10. The edge 22 can of course also be a separately-produced element that is connected to the blank, i.e., in particular with the base 12, for instance through gluing.

[0046] As can be seen from the sectional view in FIG. 2, the base 12 has a thickness B that is preferred in the range 1 to 10 mm, in particular between 1 mm and 5 mm, and especially preferred in the range 1.5 mm to 3 mm. The region 14, 16, 18 projecting above the upper side of the base 12 has a height V1 and the region projecting from the underside of the base 12 has a height V2. V1+V2+B should preferably lie between 15 mm and 25 mm. In particular the ratio of the thickness B of the base 12 to the total height H(=V1+V2+B) of the particular region 14, 16, 18 should be 1:15 to 1:1, in particular 1:10B:H1:6.

[0047] From the bottom view of the blank 10 it is similarly clear that the regions 14, 16, 18 project above the base 12.

[0048] The exemplary embodiment shown in FIGS. 4 to 6 differs from that in FIGS. 1 to 3 in that the blank 100, which also has a circular geometry, has regions that extend differently in terms of area. By way of example, four regions 114, 116, 118 and 120 are indicated. The regions 114, 116, 118, 120 extendas with the embodiment illustrated by FIGS. 1 to 3on both sides of a base 112, as can be seen in the sectional view A-A (FIG. 5). The blank 100 and thus the base 112 are also delimited by a circumferential edge 122. The description for FIGS. 1 to 3 applies here too.

[0049] Since regions of different area extend from the base 112, it follows that molded bodies of different geometries and sizes can be obtained. For example, a four to five unit bridge can be machined from the region 114, a front dental arch from the region 116, a three unit bridge from the region 118 and from the other equally dimensioned regions 120 single tooth restorations such as inlays, onlays, crowns etc. can be machined.

[0050] The same advantages, as described above, are also seen for the blank 100, in particular the material savings and the lower wear of the rotating tool, since the projecting regions 114, 116, 118, 120 can be approached from the side, i.e., transversely or perpendicularly to the axis of rotation.

[0051] The teaching according to the invention enables material to be spared. This saving may be up to 40% if, for example, the base 12, 112 has a thickness of 2 mm and the total thickness of the blank, in the regions from which the projections 14, 16, 18, 114, 116, 118, 120 emanate from the base 12, 112, is 18 mm.

[0052] As mentioned already, the blanks 10, 100 according to the invention, as well as blanks of uniform thickness, can be held in the usual holders since it is not necessary to change the profile and the dimensions of the edge 22, 122. Thereby, the limb 23, 123 of the edge 22, 122, which extends parallel to the plane defined by the blank 10, 100 and which in the sectional views extends horizontally, is an extension of the base 12, 112, as can be seen in the sectional views.

[0053] The blanks 10, 100 can be produced, for example, through additive methods by pressing, casting, forming or mechanical manufacturing methods.

[0054] It is also possible for the material of the blank at least in the region of the elevations 14, 16, 18, 114, 116, 118, 120 in particular over its height to have a different composition/different material characteristics to, for instance, obtain a color gradation that corresponds to that of natural teeth for the crowns or bridges. produced.

[0055] It is also possible to make regions comprising different material layers so that a dentine core is formed. Different translucency, strength and/or fluorescence can be generated over the height of the particular region 14, 16, 18, 114, 116, 118, 120 depending on the materials.

[0056] The exemplary embodiment according to FIGS. 7 and 9 differs from that of FIGS. 1 to 6 in that the elevated regions to be worked 214, 216, 218, 220 emanate from a base 212 that is made from a material different from that of the regions 214, 216, 218, 220. The base 212 virtually forms a carrier that has recesses in which the elevated regions to be worked 214, 216, 218, 220 are fixed, for instance through gluing. It is also possible for the base to be produced through injection molding, wherein the elevated regions 214, 216, 218, 220 are surrounded by a base material layer corresponding to the thickness of the base 212. Plastics in particular are suitable materials for the base 112, i.e., the carrier.