Lithium silicate diopside glass ceramics

• US 10,457,589 B2
• Filed: 01/21/2016
• Issued: 10/29/2019
• Est. Priority Date: 01/30/2015
• Status: Active Grant

• Current Assignee: Ivoclar Vivadent AG
• Original Assignee: Ivoclar Vivadent AG
• Inventors: Rampf, Markus, Ritzberger, Christian, Dittmer, Marc, Holand, Wolfram, Schweiger, Marcel
• Primary Examiner(s): Wiese, Noah S
• Application Number:
  US15/546,455
• Publication Number:
  US 20180009701A1
• Time in Patent Office: 1,377 Days
• CPC Class Codes: A61K 6/833 Glass-ceramic composites
• CPC Class Codes: C03B 19/06 by sintering, e.g. by cold isostatic pressing of powders and subsequent sintering, by hot pressing of powders, by sintering slurries or dispersions not undergoing a liquid phase reaction
• CPC Class Codes: C03C 10/0009 containing silica as main constituent
• CPC Class Codes: C03C 10/0027 containing SiO2, Al2O3, Li2O as main constituents
• CPC Class Codes: C03C 10/0054 containing PbO, SnO2, B2O3
• CPC Class Codes: C03C 2205/06 for dental use
• CPC Class Codes: C03C 3/078 containing an oxide of a divalent metal, e.g. an oxide of zinc
• CPC Class Codes: C03C 3/097 containing phosphorus, niobium or tantalum
• CPC Class Codes: C03C 3/112 containing fluorine
• CPC Class Codes: C03C 4/0021 for dental use
• CPC Class Codes: C03C 8/02 Frit compositions, i.e. in a powdered or comminuted form
• CPC Class Codes: C03C 8/06 containing halogen
• CPC Class Codes: C03C 8/08 containing phosphorus

Abstract

Lithium silicate-diopside glass ceramics are described which are characterized by a controllable translucence and can be satisfactorily processed mechanically and therefore can be used in particular as restoration material in dentistry.

Claims

1. Lithium silicate-diopside glass ceramic which comprises 2.0 to 8.0 wt.-% P₂O₅ and comprises lithium silicate as main crystal phase and diopside as further crystal phase.

2. Glass ceramic according to claim 1, which comprises 53.0 to 75.0 wt.-% SiO₂.

3. Glass ceramic according to claim 1, which comprises 10.0 to 23.0 wt.-% Li₂O.

4. Glass ceramic according to claim 1, which comprises 1.0 to 13.0 wt.-% CaO and/or 1.0 to 12.0 wt.-% MgO.

5. Glass ceramic according to claim 4, wherein the molar ratio of CaO to MgO is 0.5 to 2.0.

6. Glass ceramic according to claim 1, which comprises 0 to 10.0 wt.-% further alkali metal oxide Me^I₂O, wherein Me^I₂O is selected from Na₂O, K₂O, Rb₂O and/or Cs₂O.

7. Glass ceramic according to claim 1, which comprises 0 to 10.0 wt.-% oxide of trivalent elements Me^III₂O₃, wherein Me^III₂O₃ is selected from Al₂O₃, B₂O₃, Y₂O₃, La₂O₃, Ga₂O₃ and/or In₂O₃.

8. Glass ceramic according to claim 1, which comprises the following components:

9. Glass ceramic according to claim 1, which comprises lithium silicate in the form of lithium disilicate and/or lithium metasilicate.

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

11. Glass ceramic according to claim 1, which comprises 3.0 to 6.0 wt.-% P₂O₅.

22. Process for the preparation of dental restorations, wherein the glass ceramic according to claim 1 is given the shape of the desired dental restoration by pressing or machining.

23. Process according to claim 22, wherein the dental restoration is selected from bridge, inlay, onlay, veneer, abutment, partial crown, crown and shell.

12. Starting glass which comprises the following components:

13. Starting glass according to claim 12, which is present in the form of a ground powder or a compact made of ground powder.

14. Process for the preparation of a lithium silicate-diopside glass ceramic which comprises lithium silicate as main crystal phase and diopside as further crystal phase, wherein

(a) a starting glass is ground,

(b) the ground starting glass is optionally pressed to form a powder green compact and

(c) the ground starting glass or the powder green compact is subjected to at least one heat treatment at a temperature in the range of from 500°

to 1000°

C. for a period of from 5 to 120 min.

15. Lithium silicate-diopside glass ceramic, which comprises 53.0 to 70.0 wt.-% SiO₂ and comprises lithium silicate as main crystal phase and diopside as further crystal phase.

16. Lithium silicate-diopside glass ceramic, which comprises 0.5 to 10.0 wt.-% further alkali metal oxide Me^I₂O, wherein Me^I₂O is selected from Na₂O, K₂O, Rb₂O and/or Cs₂O and comprises lithium silicate as main crystal phase and diopside as further crystal phase.

17. Glass ceramic according to claim 16, which comprises 0.5 to 8.0 further alkali metal oxide Me^I₂O, wherein Me^I₂O is selected from Na₂O, K₂O, Rb₂O and/or Cs₂O.

18. Glass ceramic according to claim 16, which comprises 1.0 to 5.0 wt.-% further alkali metal oxide Me^I₂O, wherein Me^I₂O is selected from Na₂O, K₂O, Rb₂O and/or Cs₂O.

19. Lithium silicate-diopside glass ceramic, which comprises 0.1 to 8.0 wt.-% Al₂O₃ and comprises lithium silicate as main crystal phase and diopside as further crystal phase.

20. Glass ceramic according to claim 19, which comprises 1.0 to 7.0 wt.-% Al₂O₃.

21. Glass ceramic according to claim 19, which comprises 2.0 to 5.0 wt.-% Al₂O₃.