Mass production of dental restorations by solid free-form fabrication methods

• US 6,322,728 B1
• Filed: 07/09/1999
• Issued: 11/27/2001
• Est. Priority Date: 07/10/1998
• Status: Expired due to Term

• Current Assignee: Pentron Clinical Technologies, LLC (Danaher Corporation)
• Original Assignee: Jeneric/Pentron Incorporated (Danaher Corporation)
• Inventors: Brodkin, Dmitri, Panzera, Carlino, Panzera, Paul
• Primary Examiner(s): Tentoni, Leo B.
• Application Number:
  US09/350,604
• Time in Patent Office: 872 Days
• Field of Search: 264/19, 264/41, 264/113, 264/255, 264/308, 264/401, 264/497, 264/603
• US Class Current: 264/19
• CPC Class Codes: A61C 13/0003 Making bridge-work, inlays, implants or the like
• CPC Class Codes: A61C 13/0019 using three dimensional printing
• CPC Class Codes: A61K 6/802 comprising ceramics
• CPC Class Codes: A61K 6/818 comprising zirconium oxide
• CPC Class Codes: A61K 6/833 Glass-ceramic composites
• CPC Class Codes: A61K 6/838 Phosphorus compounds, e.g. apatite
• CPC Class Codes: A61K 6/884 comprising natural or synthetic resins
• CPC Class Codes: B29C 64/153 using layers of powder being selectively joined, e.g. by selective laser sintering or melting
• CPC Class Codes: B29C 64/165 using a combination of solid and fluid materials, e.g. a powder selectively bound by a liquid binder, catalyst, inhibitor or energy absorber
• CPC Class Codes: B33Y 70/00 Materials specially adapted for additive manufacturing
• CPC Class Codes: B33Y 70/10 Composites of different types of material, e.g. mixtures of ceramics and polymers or mixtures of metals and biomaterials
• CPC Class Codes: B33Y 80/00 Products made by additive manufacturing

Abstract

Solid free form fabrication techniques such as fused deposition modeling and three-dimensional printing are used to create a dental restoration. Three-dimensional printing includes ink-jet printing a binder into selected areas of sequentially deposited layers of powder. Each layer is created by spreading a thin layer of powder over the surface of a powder bed. Instructions for each layer may be derived directly from a CAD representation of the restoration. The area to be printed is obtained by computing the area of intersection between the desired plane and the CAD representation of the object. All the layers required for an aesthetically sound restoration can be deposited concurrently slice after slice and sintered/cured simultaneously. The amount of green body oversize is equivalent to the amount of shrinkage which occurs during sintering or curing. While the layers become hardened or at least partially hardened as each of the layers is laid down, once the desired final shaped configuration is achieved and the layering process is complete, in some applications it may be desirable that the form and its contents be heated or cured at a suitably selected temperature to further promote binding of the powder particles.

Claims

1. A process for manufacturing dental restorations comprising:

(a) depositing a layer of ceramic or composite material;

(b) applying a bonding material onto the ceramic or composite layer;

(c) repeating steps (a) and (b) a number of times to produce a number of layers of ceramic or composite material which are bonded to one another to form a shape of a dental restoration; and

(d) curing the shaped material to form the dental restoration.

2. The process of claim 1 wherein the ceramic material is selected from the group consisting of alumina, zirconia, mullite, silica, spinel, tricalcium phosphate, apatite, fluoroapatite, hydroxyapatite and mixtures thereof.

3. The process of claim 1 wherein the composite material is selected from the group consisting of particulate filled polymeric material, fiber filled polymeric material, whisker filled polymeric material and mixtures thereof.

4. The process of claim 3 wherein the polymeric material is selected from the group consisting of polyamides, polyesters, polyolefins, polyimides, polyacrylates, polyurethanes, vinyl esters, nylon, epoxy-based materials, styrene, styrene acrylonitrile, ABS polymers, polysulfones, polyacetals, polycarbonates, polyphenylene sulfides and mixtures thereof.

5. The process of claim 3 wherein the fibers are fabricated from the group consisting of materials selected from glass, carbon, graphite, polyaramid, polyethylene and mixtures thereof.

6. The process of claim 3 wherein the particulate material is selected from the group comsisting of silica, silicate glass, quartz, barium silicate, strontium silicate, barium borosilicate, strontium borosilicate, borosilicate, lithium silicate, amorphous silica, ammoniated or deammoniated calcium phosphate, alumina, zirconia, tin oxide, titania poly(methacrylate) and mixtures thereof.

7. The process of claim 1 wherein the layer of ceramic or composite material is cured before the deposition of another layer.

8. The process of claim 1 wherein the ceramic or composite material is deposited in a dry state.

9. The process of claim 1 wherein the ceramic or composite material is deposited in a wet state.

10. The process of claim 1 wherein the layers of material form a selected pattern.

11. The process of claim 10 wherein the selected pattern is based on a computer assisted design.

14. The method of claim 1 wherein curing comprising sintering the shaped material.

17. The process of claim 1 wherein pigments are added to the ceramic or composite material prior to deposition thereof.

18. The process of claim 1 wherein pigments are added to the ceramic or composite material after deposition thereof.

25. The process of claim 1 wherein pigments are added to the ceramic or composite material during deposition thereof.

26. The process of claim 1 wherein the dental restoration is selected from the group consisting of denture teeth, bridges, crowns, onlays and inlays.

12. A process for manufacturing a dental restoration comprising:

(a) depositing a preselected quantity of powder material;

(b) spreading the powder material in a layer of preselected thickness over a predetermined region;

(c) applying a binder material to selected regions of the powder material to cause the powder material to become bonded at the selected regions;

(d) repeating steps (a), (b) and (c) a number of times to produce a number of successive layers whereby the successive layers become bonded to one another at the selected regions;

(e) removing unbonded powder material which is not at the selected regions to form the dental restoration.

13. The process of claim 12 wherein the powder material comprises material selected from the group consisting of a ceramic and composite material.

27. The process of claim 12 wherein the dental restoration is selected from the group consisting of denture teeth, bridges, crowns, onlays and inlays.

15. A process for mass producing dental restorations comprising:

(a) depositing a layer of ceramic or composite material;

(b) applying a bonding material onto the ceramic or composite layer;

(c) repeating steps (a) and (b) a number of times to produce a number of layers of ceramic or composite material which are bonded to one another to form a shape of a dental restoration; and

(d) curing the shaped material to form the dental restoration.

28. The process of claim 15 wherein the dental restoration is selected from the group consisting of denture teeth, bridges, crowns, onlays and inlays.

16. A process for mass producing dental restorations comprising:

(a) depositing a preselected quantity of powder material;

(b) spreading the powder material in a layer of preselected thickness over a predetermined region;

(c) applying a binder material to selected regions of the powder material to cause the powder material to become bonded at the selected regions;

(d) repeating steps (a), (b) and (c) a number of times to produce a number of successive layers whereby the successive layers become bonded to one another at the selected regions;

(e) removing unbonded powder material which is not at the selected regions to form the dental restoration.

29. The process of claim 16 wherein the dental restoration is selected from the group consisting of denture teeth, bridges, crowns, onlays and inlays.

19. A process for producing a dental restoration comprising:

providing a mixture of powder material dispersed in a binder; and

dispensing the mixture from a dispensing apparatus onto a platform to build a free-standing three dimensional dental restoration.

20. The process of claim 19 wherein the mixture is dispensed in the form of a bead.

21. The process of claim 20 wherein the bead comprises a slurry or a liquidfied filament.

22. The process of claim 21 wherein the slurry comprises a polymeric composite or a mixture of a ceramic powder and a binder.

23. The process of claim 21 wherein the liquified filament comprises ceramic powder and a binder.

24. The process of claim 23 wherein the binder is a molten thermoplastic material or a wax-containing material.

30. The process of claim 19 wherein the dental restoration is selected from the group consisting of denture teeth, bridges, crowns, onlays and inlays.