Lithium silicate glass ceramic for fabrication of dental appliances

Patent metadata

Field	Value
Publication number	US-10301209-B2
Application number	US-201715656356-A
Country	US
Kind code	B2
Filing date	Jul 21, 2017
Priority date	Apr 11, 2008
Publication date	May 28, 2019
Grant date	May 28, 2019

Abstract

The present invention relates to a method of fabricating an improved lithium silicate glass ceramic and to that material for the manufacture of blocks for dental appliances using a CAD/CAM process and hot pressing system. The lithium silicate material has a chemical composition that is different from those reported in the prior art with 1 to 10% of germanium dioxide in final composition. The softening points are close to the crystallization final temperature of 800° C. indicating that the samples will support the temperature process without shape deformation.

First claim

I claim:

1. A method of making a dental restoration comprising:
obtaining a lithium silicate glass ceramic blank comprising silicon dioxide (SiO 2 ), lithium oxide (Li 2 O), and germanium oxide (GeO 2 ), wherein a molar ratio of SiO 2 /Li 2 O is between 1.8 and 1.9; and
milling the lithium silicate glass ceramic blank into a shape of a dental restoration to obtain a pre-crystallized lithium silicate glass ceramic dental restoration; and
heating the pre-crystallized lithium silicate glass ceramic dental restoration at a temperature sufficient to cause crystallization of the lithium silicate glass ceramic and to thereby obtain a crystallized lithium silicate glass ceramic dental restoration.

2. The method of claim 1 , wherein a composition of the lithium silicate glass ceramic blank comprises:
53% to 59% wt of SiO 2 ;
14% to 19% wt of Li 2 O;
1% to 9% wt of GeO 2 ; and
coloring oxides.

3. The method of claim 2 , wherein the composition of the lithium silicate glass ceramic blank also comprises at least one of the following components: Al 2 O 3 , K 2 O, B 2 O 3 , CaO, MgO, CeO 2 , P 2 O 5 , ZrO 2 , TiO 2 , Er 2 O 3 , V 2 O 5 , Ta 2 O 5 , Sm 2 O 3 , Pr 2 O 3 , and Eu 2 O 3 .

4. The method of claim 1 , wherein the crystallized lithium silicate glass ceramic dental restoration is fully crystallized.

5. The method of claim 1 , wherein the crystallized lithium silicate glass ceramic dental restoration is fully crystallized and a crystal structure of the crystallized lithium silicate glass ceramic dental restoration is lithium silicate (Li 2 SiO 3 ) containing no lithium disilicate (Li 2 Si 2 O 5 ).

6. A method of making a dental restoration comprising:
obtaining a lithium silicate glass ceramic blank comprising silicon dioxide (SiO 2 ), lithium oxide (Li 2 O), and germanium oxide (GeO 2 ), wherein a molar ratio of SiO 2 /Li 2 O is between 1.8 and 1.9; and
heating the lithium silicate glass ceramic blank at a temperature sufficient to cause crystallization of the lithium silicate glass ceramic; and
pressing the heated lithium silicate glass ceramic blank into a shape of a dental restoration to obtain a crystallized lithium silicate glass ceramic dental restoration.

7. The method of claim 6 , wherein a composition of the lithium silicate glass ceramic blank comprises:
53% to 59% wt of SiO 2 ;
14% to 19% wt of Li 2 O;
1% to 9% wt of GeO 2 ; and
coloring oxides.

8. The method of claim 7 , wherein the composition of the lithium silicate glass ceramic blank also comprises at least one of the following components: Al 2 O 3 , K 2 O, B 2 O 3 , CaO, MgO, CeO 2 , P 2 O 5 , ZrO 2 , TiO 2 , Er 2 O 3 , V 2 O 5 , Ta 2 O 5 , Sm 2 O 3 , Pr 2 O 3 , and Eu 2 O 3 .

9. The method of claim 6 , wherein the crystallized lithium silicate glass ceramic dental restoration is fully crystallized.

10. The method of claim 6 , wherein the crystallized lithium silicate glass ceramic dental restoration is fully crystallized and a crystal structure of the crystallized lithium silicate glass ceramic dental restoration is lithium silicate (Li 2 SiO 3 ) containing no lithium disilicate (Li 2 Si 2 O 5 ).

11. A method of making a dental restoration comprising:
obtaining a lithium silicate glass ceramic blank comprising silicon dioxide (SiO 2 ), lithium oxide (Li 2 O), and germanium oxide (GeO 2 ), wherein a molar ratio of SiO 2 /Li 2 O is between 1.8 and 1.9; and
milling the lithium silicate glass ceramic blank into a shape of a dental restoration.

12. The method of claim 11 , wherein a composition of the lithium silicate glass ceramic blank comprises:
53% to 59% wt of SiO 2 ;
14% to 19% wt of Li 2 O;
1% to 9% wt of GeO 2 ; and
coloring oxides.

13. The method of claim 12 , wherein the composition of the lithium silicate glass ceramic blank also comprises at least one of the following components: Al 2 O 3 , K 2 O, B 2 O 3 , CaO, MgO, CeO 2 , P 2 O 5 , ZrO 2 , TiO 2 , Er 2 O 3 , V 2 O 5 , Ta 2 O 5 , Sm 2 O 3 , Pr 2 O 3 , and Eu 2 O 3 .

14. The method of claim 11 , further comprising:
heating the lithium silicate glass ceramic blank at a temperature sufficient to cause crystallization of the lithium silicate glass ceramic.

Assignees

• Glidewell James R Dental Ceramics Inc

Inventors

• Castillo Rodolfo

Classifications

• A61K6/833

  Glass-ceramic composites · CPC title

• A61K6/78

  Pigments · CPC title

• A61K6/82

  comprising hafnium oxide · CPC title

• A61K6/813

  comprising iron oxide · CPC title

• A61K6/807

  comprising magnesium oxide · CPC title