Solid free-form fabrication methods for the production of dental restorations

• US 20020125592A1
• Filed: 10/22/2001
• Published: 09/12/2002
• Est. Priority Date: 07/10/1998
• Status: Active Grant

• Current Assignee: Pentron Clinical Technologies, LLC (Danaher Corporation)
• Original Assignee: Jeneric/Pentron Incorporated (Danaher Corporation)
• Inventors: Panzera, Carlino, Schulman, Martin L.
• Granted Patent: US 6,808,659 B2
• Time in Patent Office: Days
• US Class Current: 264/16
• 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 6/838 Phosphorus compounds, e.g. apatite
• CPC Class Codes: A61K 6/84 comprising metals or alloys
• CPC Class Codes: A61K 6/849 comprising inorganic cements
• 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 30/00 Apparatus for additive manufacturing; Details thereof or accessories therefor
• CPC Class Codes: B33Y 70/00 Materials specially adapted for additive manufacturing
• CPC Class Codes: B33Y 80/00 Products made by additive manufacturing
• CPC Class Codes: Y10T 29/49567 Dental appliance making
• CPC Class Codes: Y10T 29/49568 Orthodontic device making

Abstract

Solid free form fabrication techniques such as fused deposition modeling and three-dimensional printing are used to create a shell or die used in the manufacture of a dental restoration. Three-dimensional printing comprises 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 shell can be deposited concurrently slice after slice and sintered/cured simultaneously. 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, cooled or cured at a suitably selected temperature to further promote the integrity of solid free-form structures.

Claims

1. A process for manufacturing a dental restoration comprising:

forming a die for a coping or a framework;

forming the coping or the framework from a ceramic material;

wherein the ceramic material is in its green state or in a partially sintered state;

placing the coping or framework on the die; and

fully sintering the coping or framework.

2. The process of claim 1 wherein the ceramic material comprises alumina, zirconia, silicon nitride, silicon carbide, silica-alumina-nitride, mullite, garnets, porcelain or mixtures thereof.

3. The process of claim 2 wherein the porcelain comprises leucite, lithium disilicate, mullite or mica.

4. The process of claim 1 wherein the die is fabricated by milling or rapid prototyping.

5. The process of claim 1 wherein the coping or framework is fabricated by milling or rapid prototyping.

6. The process of claim 1 wherein the die is fabricated of gypsum, silica, leucite, zirconia, hafnia, zirconia, alumina, magnesia, hafnia, zircon, aluminosilicate, cordierite, mica, silicon nitride, silicon carbide, silica-alumina-nitrides, mullite, garnet, or mixtures thereof.

7. The process of claim 1 wherein the die is fabricated of a metal or alloy.

8. The process of claim 7 wherein the metal or alloy comprises molybdenum, nickel or mixtures thereof.

9. The process of claim 1 wherein the coping or framework is in the shape of denture teeth, a bridge, crown, space maintainers, tooth replacement appliance, orthodontic retainer, denture, post, jacket, inlay, onlay, facing, veneer, facet, implant, abutment, splint, partial crown, cylinder, pin, or connector.

13. A dental restoration formed by the process of claim 1.

10. A process for manufacturing a dental restoration comprising:

manufacturing a shell by rapid prototyping, wherein the shell is a replica of a coping;

covering the shell with refractory material;

burning out the shell to provide a space in the refractory material;

filling the space with ceramic, metal or composite material to form the dental restoration.

11. The process of claim 10 wherein the filling step comprises injecting or vibrating the ceramic, metal or composite material into the space.

12. The process of claim 10 wherein the ceramic, metal or composite material is in the form of a slurry and is poured into the space.

14. A dental restoration formed by the process of claim 10.