CeO2-stabilized ZrO2 ceramics for dental applications

Patent metadata

Field	Value
Publication number	US-11040914-B2
Application number	US-201916394061-A
Country	US
Kind code	B2
Filing date	Apr 25, 2019
Priority date	Jun 20, 2012
Publication date	Jun 22, 2021
Grant date	Jun 22, 2021

Abstract

The present invention is directed to a porous pre-densified CeO2-stabilized ZrO2 ceramic having a density of 50.0 to 95.0%, relative to the theoretical density of zirconia, and an open porosity of 5 to 50% as well as to a densified CeO2-stabilized ZrO2 ceramic having a density of 97.0 to 100.0%, relative to the theoretical density of zirconia, and wherein the grains of the ceramic have an average grain size of 50 to 1000 nm, methods for the preparation of the pre-densified and densified ceramics and their use for the manufacture of dental restorations.

First claim

The invention claimed is:

1. Densified CeO 2 -stabilized ZrO 2 ceramic having a density of 97.0 to 100.0%, relative to the theoretical density of zirconia which is 6.23 g/cm 3 , wherein the ceramic comprises 6 to 14 mol % of CeO 2 and wherein the grains of the ceramic have an average grain size of 400 to 700 nm.

2. Densified ceramic according to claim 1 having a density of 98.0 to 100.0%.

3. Densified ceramic according to claim 1 , wherein the grains of the ceramic have an average grain size of 100 to 800 nm.

4. Densified ceramic according to claim 1 comprising tetragonal ZrO 2 in an amount of 90 to 100 vol.-% based on the total volume of crystals of the densified ceramic.

5. Densified ceramic according to claim 1 , wherein the pores of the ceramic have a mean pore diameter of less than 150 nm.

6. Densified ceramic according to claim 1 having an open porosity of less than 1% and/or a closed porosity of less than 1%.

7. Densified ceramic according to claim 2 having a density of 99.5 to 100.0%.

8. Densified ceramic according to claim 2 having a density of about 100.0%.

9. Densified ceramic according to claim 4 comprising tetragonal ZrO 2 in an amount of 95 to 100 vol.-%, based on the total volume of crystals of the densified ceramic.

10. Densified ceramic according to claim 4 comprising tetragonal ZrO 2 in an amount of about 100 vol.-%, based on the total volume of crystals of the densified ceramic.

11. Densified ceramic according to claim 5 , wherein the pores of the ceramic have a mean pore diameter of less than 100 nm.

12. Densified ceramic according to claim 5 , wherein the pores of the ceramic have a mean pore diameter of less than 80 nm.

13. Densified ceramic according to claim 5 , wherein the pores of the ceramic have a mean pore diameter of less than 20 nm.

14. Densified ceramic according to claim 5 , wherein the pores of the ceramic have a mean pore diameter of less than about 10 nm.

15. Method for preparing a densified CeO 2 -stabilized ZrO 2 ceramic having a density of 97.0 to 100.0%, relative to the theoretical density of zirconia which is 6.23 g/cm3, wherein the ceramic comprises 6 to 14 mol % of CeO 2 and wherein the grains of the ceramic have an average grain size of 50 to 1000 nm, wherein said method comprises
(a′) providing a porous CeO 2 -stabilized ZrO 2 ceramic having a density of 50.0 to 95.0%, relative to the theoretical density of zirconia, and an open porosity of 5 to 50%, wherein the step of providing preferably includes pre-densifying a CeO 2 -containing ZrO 2 starting material to provide the porous ceramic 22 ,
(c) optionally shaping the porous ceramic provided in step (a′), and
(d) densifying the porous ceramic provided in step (a) or obtained in step (c) to obtain the densified CeO 2 -stabilized ZrO 2 ceramic, wherein densifying in step (d) is performed in an oxygen-containing atmosphere by sintering in air.

16. Method of using a porous CeO 2 -stabilized ZrO 2 ceramic having a density of 50.0 to 95.0%, relative to the theoretical density of zirconia, and an open porosity of 5 to 50%, wherein the pores of the ceramic have a mean pore diameter of 10 to 500 nm, for the preparation of dental restorations, dental frameworks, dental abutments and dental implants, wherein the method comprises the step of shaping the porous CeO 2 -stabilized ZrO 2 ceramic to the geometry of the desired dental restoration, dental framework, dental abutment or dental implant.

17. Method of using a densified CeO 2 -stabilized ZrO 2 ceramic according to claim 1 for the preparation of dental restorations, dental frameworks, dental abutments and dental implants.

Assignees

• Ivoclar Vivadent Ag

Inventors

• Ritzberger Christian
• Rothbrust Frank
• Schweiger Marcel
• Courtois Nicolas
• CHEVALIER Jérôme
• Reveron Helen
• Höland Wolfram
• Rheinberger Volker

Classifications

• C04B35/486 Primary

  Fine ceramics · CPC title

• C04B2235/3272

  Iron oxides or oxide forming salts thereof, e.g. hematite, magnetite · CPC title

• C04B2235/3246

  Stabilised zirconias, e.g. YSZ or cerium stabilised zirconia · CPC title

• C04B2235/9661

  Colour · CPC title

• C04B2235/604

  Pressing at temperatures other than sintering temperatures · CPC title