Method of producing a dental product

• US 8,231,825 B2
• Filed: 05/28/2008
• Issued: 07/31/2012
• Est. Priority Date: 06/07/2007
• Status: Active Grant

• Current Assignee: Nobel Biocare Services AG (Envista Holdings Corporation)
• Original Assignee: Nobel Biocare Services AG (Envista Holdings Corporation)
• Inventors: Eriksson, Cecilia, Jörneus, Lars, Berggren, Carina, Brännvall, Petrus
• Primary Examiner(s): Wollschlager, Jeffrey
• Assistant Examiner(s): YI, STELLA KIM
• Application Number:
  US12/663,517
• Publication Number:
  US 20100323327A1
• Time in Patent Office: 1,525 Days
• Field of Search: 264 16- 20, 264/677, 264/678, 264/497, 264/605, 264/652, 298/961, 298/961.1, 433/167, 433/168.1, 433/171, 433/199.1, 433/201.1, 433/6, 433/153, 433/154, 433/156, 433/157
• US Class Current: 264/678
• CPC Class Codes: A61C 13/0022 Blanks or green, unfinished dental restoration parts
• CPC Class Codes: A61C 13/083 Porcelain or ceramic teeth A61C13/081 takes precedence; preparations A61K6/80
• CPC Class Codes: A61C 5/77 Methods or devices for making crowns

Abstract

Methods of producing a dental product are disclosed. Certain methods include the steps of providing a pre-sintered blank made from a green body of ceramic material, performing a machining operation on the blank, and subsequently sintering the blank to its final density in a sintering operation performed at a temperature in the range of 1300° C. to 1650° C. The pre-sintered blank that is provided may have a strength in the range of 53-107 MPa.

Claims

1. A method of producing a dental product, the method comprising the steps of:

providing a blank made from a green body of ceramic material, performing a machining operation on the blank, and subsequently sintering the blank to its final density in a sintering operation performed at a temperature in the range of 1300°

C. to 1650°

C., and wherein the blank that is provided has a bend strength in the range of 53-74 MPa, and

wherein during the machining operation, the blank is machined into a bridge structure and a support body that is linked to the bridge structure by several retaining sections that extend from the support body to the bridge structure, the blank machined to a shape where the bridge structure forms an arch and at least some of the retaining sections are shaped as spokes that extend from a common hub in the support body to the bridge structure, and

during the sintering of the blank to its final density, the several retaining sections hold the bridge structure connected to the support body.

2. A method according to claim 1, wherein the blank has a bend strength in the range of 56-65 MPa.

3. A method according to claim 1, wherein the blank has a bend strength in the range of 56-65 MPa in its pre-sintered condition.

4. A method according to claim 1, wherein the blank has a density in the range of 2.9 g/cm³-3.80 g/cm³ in its presintered condition.

5. A method according to claim 1, wherein the blank has a density in the range of 3.0 g/cm³-3.5 g/cm³ in its presintered condition.

6. A method according to claim 1, wherein the blank has been made of a green body of zirconium oxide that has been isostatically pressed and wherein pre-sintering of the green body is performed at a temperature in the range of 970°

C.-1150°

C.

7. A method according to claim 6, wherein the pre-sintering is performed at a temperature in the range of 1050°

C.-1120°

C.

8. A method according to claim 1, wherein prior to pre-sintering, the green body blank has been isostatically pressed at a pressure of 200 MPa-300 MPa.

9. A method according to claim 1, wherein after machining, the blank is sintered to a final density of 6.00 g/cm³-6.09 g/cm³.