SINGLE- OR MULTI-UNIT DENTAL RESTORATION, AND METHOD OF PRODUCING THE SAME

Abstract

The invention relates to a single- or multi-unit dental restoration, which consists of a support structure and a veneer, which support structure is in particular made from oxide ceramics by means of additive manufacturing, particularly preferably by means of rapid prototyping, wherein the veneer is produced by pressing a ceramic material, such as a glass ceramic or composite material, which is more translucent than the support structure, characterized in that the veneer fills and/or penetrates recesses of the support structure (12) configured as a net or frame structure or as a reinforcement, wherein it is particularly provided that the recesses penetrate through the support structure (12).

Claims

1. A single- or multi-unit dental restoration, comprising a support structure and a veneer, which support structure is made from oxide ceramics by additive manufacturing, wherein the veneer is produced by pressing a ceramic material, which is more translucent than the support structure, wherein the veneer fills and/or penetrates recesses of the support structure (12) configured as a net or frame structure or as a reinforcement, and wherein the recesses extend through the support structure (12).

2. The dental restoration as claimed in claim 1, wherein the strength of the completed dental restoration is higher than the combined strength of the support structure and the veneer separately.

3. The dental restoration as claimed in claim 1, wherein the support structure (12) forms reinforcement ribs which extend at least partially between abutment teeth and which are configured to receive vertical loads.

4. The dental restoration as claimed in claim 1, wherein the support structure (12) comprises reinforcement struts which optionally extend transversely relative to the longitudinal extension of the dental ceramic product and which are positioned towards the cervical area of the abutment teeth or to the stump thereof.

5. The dental restoration as claimed in claim 1, wherein the restoration is configured as a crown, optionally with an attachment, and comprises interdental connectors which extend at least partially obliquely relative to the longitudinal extension of the dental restoration (10), and are tilted towards the cervical area of the abutment teeth.

6. The dental restoration as claimed in claim 1, wherein the CAD software, by which the mold is produced, also sets or suggests the parting surfaces between the oxide ceramics and the veneer, and wherein the interfaces are at least twice as large as the cross-sectional area of the tooth to be restored at the occlusal/incisal plane.

7. The dental restoration as claimed in claim 1, wherein the support structure (12) is configured such that it at least partially surrounds a cavity and comprises a wall thickness (24) of less than 4 mm.

8. The dental restoration as claimed in claim 1, wherein the veneer is produced from a positive model which is embedded in a muffle and burnt out, wherein the produced cavity is filled to form the dental restoration.

9. The dental restoration as claimed in claim 1, wherein the support structure (12) comprises fixation projections which are embedded into the embedding mass and predetermine the position of the support structure (12) in the cavity of the muffle which is produced.

10. The dental restoration as claimed in claim 1, wherein the support structure (12) comprises fixation projections and the veneer comprises matching notches which engage one another in a positive manner each and which are configured on a non-labial side of the dental restoration (10).

11. The dental restoration as claimed in claim 1, wherein the net or frame structure is made up of struts (44) which extend between joints (46), wherein at least one knot (46) is connected to at least three struts (44), and in that the struts have a length of at least three times of a diameter at a place of a smallest diameter.

12. The dental restoration as claimed in claim 11, characterized in that the struts (44) comprise an enlarged diameter, compared with a diameter at a center of the struts (44), positioned at the knot (46).

13. The dental restoration as claimed in claim 1, wherein the reinforcement comprises at least one pre-fabricated reinforcement element in a standard geometry.

14. A dental restoration which comprises a ceramic or metallic support which forms a support structure and a veneer, wherein the ceramic support is made by additive manufacturing, from a curable mass which is filled with an oxide or glass ceramic material, and wherein the veneer is produced by pressing a ceramic material, which is more translucent than the ceramic material of the support structure, wherein the ceramic support (12) is configured as a net or frame structure by forming recesses which are filled with the veneer.

15. The dental restoration as claimed in claim 14, wherein the support structure is produced by pressing a green product made of a glass ceramic material into a cavity in a muffle, which cavity is provided by embedding a positive mold which has been produced by CAD design by means of additive manufacturing with the aid of an embedding mass, said glass ceramic material comprising a higher strength than the veneer, and wherein the veneer is produced by pressing a glass ceramic or composite material.

16. The dental restoration as claimed in claim 14, wherein the cavity for the veneer is filled with a glass ceramic material in a pressing process, wherein the material for the support structure (12) comprises a higher strength than the material for the veneer, and wherein the veneer is produced by pressing a glass ceramic, or a composite, material which is more translucent than the glass ceramic material of the support structure (12).

17. The dental restoration as claimed in claim 14, wherein the support structure is a metallic support structure which is produced by means of additive manufacturing selected from stereo lithography manufacturing of a model made of a material which can be burnt out and subsequent embedding and casting of the metallic support structure, or Selective Laser Sintering, and wherein then the metallic support structure is opaquerized and, a glass ceramic veneer ceramic material is pressed through the recesses by means of a pressing process.

18. A method of producing a single- or multi-unit dental restoration, in which a veneer is produced by CAD design in such a manner that the CAD software initially constructs a support structure which is made from oxide or glass ceramic materials by additive manufacturing, and that the veneer is produced by means of muffle presses, from a glass ceramic material, which is more translucent than the oxide ceramic material, characterized in that the CAD software determines the boundary surfaces between the ceramic support (12) and the veneer such that the ceramic support (12) is configured in a net, honeycomb or frame structure by forming recesses which are filled by the veneer glass ceramic material.

19. The dental restoration as claimed in claim 1, wherein the additive manufacturing comprises rapid prototyping and wherein the ceramic material comprises a glass ceramic or composite material.

20. The dental restoration as claimed in claim 6, wherein the interfaces are at least three times as large as the cross-sectional area of the tooth to be restored at the occlusal/incisal plane.

21. The dental restoration as claimed in claim 6, wherein the interfaces are at least five times as large as the cross-sectional area of the tooth to be restored at the occlusal/incisal plane.

22. The dental restoration as claimed in claim 7, wherein the support structure (12) comprises a wall thickness (24) of less than 1 mm.

23. The dental restoration as claimed in claim 11, wherein the struts have a length of at least five times of the diameter at the place of the smallest diameter.

24. The dental restoration as claimed in claim 14 wherein the additive manufacturing comprises stereo lithography and wherein the curable mass comprises a photopolymerizable slurry which is debound and densely sintered in a thermal process, and whose veneer is produced by pressing a ceramic material, such as a glass ceramic or a composite material, which is more translucent than the ceramic material of the support structure, characterized in that the ceramic support (12) is configured as a net or frame structure by forming recesses which are filled with the glass ceramic or the composite material, as a veneer, respectively.

25. The method as claimed in claim 18 wherein the additive manufacturing comprises rapid prototyping.

Description

[0055] Further advantages, details and features may be taken from the following description of several exemplary embodiments of the invention in conjunction with the drawings, in which:

[0056] FIG. 1 shows a schematic view of an inventive dental restoration showing the ceramic support of a bridge, in a bottom view;

[0057] FIG. 2 shows a schematic perspective side view of the ceramic support of the bridge according to FIG. 1;

[0058] FIG. 3a shows a schematic side view of a modified embodiment of the inventive dental restoration;

[0059] FIG. 3b shows a section along the line A-A from FIG. 3a;

[0060] FIG. 4 shows a schematic view of a further embodiment of an inventive dental restoration; and

[0061] FIG. 5 shows a schematic view of a further embodiment of an inventive dental restoration.

[0062] The dental restoration 10 illustrated in FIG. 1 is configured as a bridge and comprises the ceramic support 12 apparent from FIG. 1. This ceramic support 12 is configured as a net or frame structure in the broadest sense, wherein the simplified view is due to the graphic illustration and, in fact, can be much more complex and finely structured in practice. Preferably, the ceramic support 12 is an oxide ceramic material, but can also be a glass ceramic material with a higher strength than the veneer.

[0063] In the exemplary embodiment illustrated, the support structure 12 comprises two round recesses 14 and 16 in any case, which are allocated to the bridge teeth and which are open cervically. The recesses 14 and 16 run conically—as can be seen from FIG. 2—and are rounded at the incisal/occlusal end surface.

[0064] Further recesses 18, 20 and 22 extend between them and next to them, which recesses are related to the bridge units provided thereat, and are also open cervically.

[0065] The ceramic support 12 according to FIG. 1 is constructed such that it has a constant wall thickness of 1.5 mm. It has become evident that the thin wall thickness is decisive to accelerate the debinding process such that in the construction illustrated debinding is possible within 8 hours.

[0066] It is to be understood that the wall thickness 24 in the embodiment according to FIG. 1 can still be reduced considerably, for instance to between 0.6 mm and 0.8 mm, leading to a correspondingly reduced debinding time.

[0067] Veneer recesses 28 and 30 are allocated to the abutment teeth of the dental restoration and serve to be attached to the tooth stump located thereat in a way known per se.

[0068] The ceramic support is embedded completely into a veneer or ceramic veneer. This predetermines the outer shape in particular at the occlusal surface of the dental restoration and also fills the recesses 14 to 22, while the veneer recesses 28 and 30 are preferably only lined with the ceramic veneer in order to ensure a slightly less hard mounting of the dental restoration to the respective related tooth stump.

[0069] An anatomically favorable mounting is of importance to keep the wear of the antagonist as small as possible and to bring the chewing sensation of the dental restoration closer to the natural chewing sensation.

[0070] FIG. 2 illustrates that all the recesses 14 to 22 extend towards the bottom, that is to say in the cervical direction, in a slightly conically widened manner. This facilitates and improves the pressing of the filling ceramic material into the recesses.

[0071] In a way known per se, the bridge units 32, 34 and 36 comprise a relatively narrow transverse extension in the vestibular-palatinal/lingual direction. In the exemplary embodiment illustrated it amounts to less than the extension in the mesial-distal direction, but also to less than the extension in the occlusal-cervical direction. However, the exterior width of the bridge units 32, 36 (in turn as viewed from the vestibular direction) is not substantially smaller or even larger than the extension into both other dimensions; however, due to the voluminously dimensioned recesses 18, 20 and 22 the actual material thickness is substantially smaller.

[0072] From FIG. 3a and FIG. 3b a further embodiment of the inventive dental restoration is apparent. Here, the veneer or the envelope ceramic material 40 is illustrated schematically. It also penetrates the plurality of recesses 42 which are provided in the ceramic support 12 located thereat. Here, the ceramic support 12 comprises a honeycomb structure, and the recesses are longitudinally oval in the vertical direction (that is to say as viewed cervically-occlusally), as can be seen from FIG. 3.

[0073] Preferably, the recesses 42 also extend three-dimensionally similar to an open-pored sponge, wherein this cannot be seen from FIG. 3a and FIG. 3b. In this exemplary embodiment, struts 44 are provided in any case which can also have a circular or longitudinally oval cross-section. When a longitudinally oval cross-section is selected, the main axis of the longitudinally oval cross section preferably extends also in the vertical direction.

[0074] From FIG. 4 a modified embodiment of an inventive ceramic support and the related veneer is apparent. Here, the net or frame structure is configured like a tree or is at least similar to a tree structure. Fine branches of the individual struts which cross one another are connected with adjacent points via the veneer 40 such that virtual knots 46 are produced which are provided plurally and which serve to support one another.

[0075] For this purpose, the struts 44a and 44b of the ceramic support 12 extend transversely to one another in space, but against one another such that they come close to one another at one position. Preferably, the struts 44a and 44b do not touch one another but remain at a distance of between 10 mm and 100 mm which is filled with filling ceramic material. The virtual knot 46 is formed by this approximation area.

[0076] It is to be understood that the trunks 48 and 50 of the tree structure are connected to receptacles for the abutment teeth, which are not shown in FIG. 4, in a way known per se and in the usual manner.

[0077] From FIG. 5 a further three-dimensionally designed net or frame structure of the ceramic support 12 is apparent. This ceramic support consists of a three-dimensional frame with structures which engage one another, for instance of the type of hexahedrons, octahedrons or also cubes.

[0078] It is also possible to configure the recesses 18 similar to dense spherical packings and to design them by means of a computer such that the wall thickness of the struts 44 amounts constantly to about 100 mm each. In the area of the knots 46 a thickening to 200 mm takes place and at the transition between the strut 44 and the knot 46 the support structure is configured conically.

[0079] It is to be understood that in the realization of the support structure for instance by FEM, the possible masticatory forces can be involved and the support structure can be configured in a load-dependent manner appropriately.