Method of producing a dental restoration using CAD/CAM

• US 5,775,912 A
• Filed: 08/16/1996
• Issued: 07/07/1998
• Est. Priority Date: 08/16/1996
• Status: Expired due to Term

• Current Assignee: Ardent, Inc. (Ivoclar Vivadent AG)
• Original Assignee: American Thermocraft Corporation
• Inventors: Brightly, Richard A., Pruden, Jana, DiMeglio, Lisa M., Panzera, Carlino
• Primary Examiner(s): LEWIS, RALPH A
• Application Number:
  US08/699,149
• Time in Patent Office: 690 Days
• Field of Search: 433/213, 433/223, 433/229, 433/212.1, 364/474.03, 364/474.05, 364/474.39
• US Class Current: 433/223
• CPC Class Codes: A61C 13/0004 Computer-assisted sizing or machining of dental prostheses
• CPC Class Codes: A61C 13/083 Porcelain or ceramic teeth A61C13/081 takes precedence; preparations A61K6/80

Abstract

A method of making a dental porcelain restoration comprises providing a soft-sintered dental porcelain pellet; milling the soft-sintered pellet under the control of a CAD/CAM system to provide a tooth structure; investing the tooth structure with an investment refractory material to provide an invested tooth structure; fusing the invested tooth structure; and removing the investment refractory material from the fused tooth structure to provide the dental restoration.

Claims

1. A method of making a dental restoration which comprises:

providing a soft-sintered dental porcelain pellet;

milling the soft-sintered dental porcelain pellet under the control of a CAD/CAM system to provide a tooth structure;

investing the tooth structure with an investment refractory material to provide an invested tooth structure;

fusing the invested tooth structure; and

removing the investment refractory material from the fused tooth structure to provide the dental restoration.

2. The method of claim 1 wherein the soft-sintered dental porcelain pellet possesses a density which is less than about 85 percent of the theoretical density of the pellet.

3. The method of claim 1 wherein the soft-sintered pellet is formed by compressing at ambient temperature dental porcelain powder into a pellet and subsequently heating the pellet to a temperature below the fusion temperature of the dental porcelain to provide a pellet possessing a density which is less than about 85 percent of the theoretical density.

4. The method of claim 3, wherein the fusion temperature is about 1027°

C.

5. The method of claim 4, wherein the temperature below the fusion temperature ranges from about 650°

C. to about 925°

C.

6. The method of claim 3, wherein the dental porcelain powder is compressed at about 5000 psi.

7. The method of claim 1 wherein the soft-sintered dental porcelain pellet possesses a density which is less than about 75 percent of the theoretical density of the pellet.

8. The method of claim 1 wherein the soft-sintered pellet is formed by compressing at ambient temperature dental porcelain powder into a pellet and subsequently heating the pellet to a temperature below the fusion temperature of the dental porcelain to provide a pellet possessing a density which is less than about 75 percent of the theoretical density.

9. The method of claim 8, wherein the fusion temperature is about 1027°

C.

10. The method of claim 9, wherein the temperature below the fusion temperature ranges from about 650°

C. to about 925°

C.

11. The method of claim 8, wherein the dental porcelain powder is compressed at about 5000 psi.

12. The method of claim 1, wherein the soft-sintered pellet has a fusion temperature of about 1150°

C.