Lithium silicate-wollastonite glass ceramic

Patent metadata

Field	Value
Publication number	US-10590028-B2
Application number	US-201615754176-A
Country	US
Kind code	B2
Filing date	Sep 2, 2016
Priority date	Sep 30, 2015
Publication date	Mar 17, 2020
Grant date	Mar 17, 2020

Abstract

Lithium silicate-wollastonite glass ceramics are described which are characterized by a controllable translucence and can be easily machined and therefore can be used in particular as restoration material in dentistry.

First claim

The invention claimed is:

1. Lithium silicate-wollastonite glass ceramic, which comprises 1.0 to 7.0 wt.-% P 2 O 3 and comprises lithium silicate as a crystal phase and wollastonite as a further crystal phase.

2. Glass ceramic according to claim 1 , which comprises 55.0 to 74.0 wt.-% SiO 2 .

3. Glass ceramic according to claim 1 , which comprises 10.0 to 18.0 wt.-% Li 2 O.

4. Glass ceramic according to claim 1 , which comprises 4.0 to 17.0 wt.-% CaO.

5. Glass ceramic according to claim 1 , which comprises 0.5 to 6.0 wt.-% Al 2 O 3 .

6. Glass ceramic according to claim 1 , which comprises 0 to 5.0 wt.-% K 2 O.

7. Glass ceramic according to claim 1 , which comprises 2.0 to 6.0 wt.-% P 2 O 3 .

8. Glass ceramic according to claim 1 , which comprises 0 to 13.0 wt.-% further alkali metal oxide Me I 2 O, wherein Me I 2 O is selected from Na 2 O, Rb 2 O and/or Cs 2 O.

9. Glass ceramic according to claim 1 , which comprises 0 to 6.0 wt.-% further oxide of divalent elements Me II O, wherein Me II O is selected from MgO, SrO and/or ZnO.

10. Glass ceramic according to claim 1 , which comprises 0 to 6.0 wt.-% oxide of trivalent elements Me III 2 O 3 , wherein Me III 2 O 3 is selected from B 2 O 3 , Y 2 O 3 , La 2 O 3 and/or Er 2 O 3 .

11. Glass ceramic according to claim 1 , which comprises 0 to 8.0 wt.-% further oxide of tetravalent elements Me IV O 2 , wherein Me IV O 2 is selected from ZrO 2 , GeO 2 , CeO 2 , TiO 2 and/or SnO 2 .

12. Glass ceramic according to claim 1 , which comprises 0 to 6.0 wt.-% further oxide of pentavalent elements Me V 2 O 5 , wherein Me V 2 O 5 is selected from V 2 O 5 , Ta 2 O 5 and/or Nb 2 O 5 .

13. Glass ceramic according to claim 1 , which comprises 0 to 6.0 wt.-% oxide of hexavalent elements Me VI O 3 , wherein Me VI O 3 is selected from WO 3 and/or MoO 3 .

14. Glass ceramic according to claim 1 , which comprises at least one of the following components in the amounts specified:

Component
wt.-%

SiO 2
56.0 to 74.0  

Li 2 O
10.0 to 18.0  

CaO
4.0 to 17.0 

Al 2 O 3
0.5 to 6.0  

K 2 O
0 to 5.0

P 2 O 5
1.0 to 7.0  

Me I 2 O
 0 to 13.0

Me II O
0 to 6.0

Me III 2 O 3
0 to 6.0

Me IV O 2
0 to 8.0

Me V 2 O 5
0 to 6.0

Me VI O 3
 0 to 6.0.

15. Glass ceramic according to claim 1 , which comprises lithium disilicate and/or lithium metasilicate.

16. Glass ceramic according to claim 1 , which comprises lithium metasilicate or lithium disilicate as main crystal phase.

17. Lithium silicate-wollastonite glass ceramic, which comprises lithium silicate as a crystal phase and wollastonite and lithium phosphate as further crystal phases.

18. Glass ceramic according to claim 1 , which is present in the form of a blank or a dental restoration.

19. Starting glass, which comprises 1.0 to 7.0 wt.-% P 2 O 5 and comprises nuclei for the crystallization of lithium silicate as a crystal phase and wollastonite as a further crystal phase.

20. Starting glass according to claim 19 , which is present in the form of a ground powder or a compact made of ground powder.

21. Process for the preparation of the glass ceramic according to claim 1 , in which
(a) a starting glass which comprises 1.0 to 7.0 wt.-% P 2 O 5 and comprises nuclei for the crystallization of lithium silicate and/or wollastonite is ground,
(b) optionally the ground starting glass is pressed to form a powder compact and
(c) the ground starting glass or the powder compact is subjected to at least one heat treatment at a temperature in the range of 700° to 950° C. for a period of 5 to 120 min.

22. Process for the preparation of a dental restoration comprising a bridge, inlay, onlay, veneer, abutment, partial crown, crown or facet, in which a lithium silicate-wollastonite glass ceramic, which comprises lithium silicate as a crystal phase and wollastonite as a further crystal phase, is given the shape of the desired dental restoration by pressing or machining.

Assignees

• Ivoclar Vivadent Ag

Inventors

• Dittmer Marc
• Höland Wolfram
• Rampf Markus
• Schweiger Marcel

Classifications

• C03C10/0027

  containing SiO2, Al2O3, Li2O as main constituents · CPC title

• A61K6/824

  comprising transition metal oxides · CPC title

• C03C4/0021

  for dental use · CPC title

• A61K6/818

  comprising zirconium oxide · CPC title

• A61K6/822

  comprising rare earth metal oxides · CPC title