Process for the preparation of shaped translucent lithium disilicate glass ceramic products

• US 6,420,288 B2
• Filed: 11/06/1998
• Issued: 07/16/2002
• Est. Priority Date: 11/10/1997
• Status: Expired due to Term

• Current Assignee: Ivoclar AG
• Original Assignee: Ivoclar AG
• Inventors: Cramer von Clausbruch, Sascha, Rheinberger, Volker, Schweiger, Marcel, Höland, Wolfram
• Primary Examiner(s): Koslow, C. Melissa
• Application Number:
  US09/187,716
• Publication Number:
  US 20020010063A1
• Time in Patent Office: 1,348 Days
• Field of Search: 106/35, 501/3, 501/7, 501/64, 501/68, 501/69, 501/72, 65/331, 65/334, 65/339, 651/02
• US Class Current: 501/7
• CPC Class Codes: A61K 6/78 Pigments
• CPC Class Codes: A61K 6/807 comprising magnesium oxide
• CPC Class Codes: A61K 6/816 comprising titanium oxide
• CPC Class Codes: A61K 6/818 comprising zirconium oxide
• CPC Class Codes: A61K 6/822 comprising rare earth metal oxides
• CPC Class Codes: A61K 6/824 comprising transition metal oxides
• CPC Class Codes: A61K 6/833 Glass-ceramic composites
• 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 17/02 with glass C03C17/34, C03C17/44 take precedence
• CPC Class Codes: C03C 4/0021 for dental use

Abstract

A process is described for the preparation of shaped translucent lithium disilicate glass ceramic products which are characterized by high strength and good chemical stability and may be processed by pressing in the plastic state or milling to finished glass ceramic products which may be used in particular as dental restorations.

Claims

1. A process for the preparation of shaped translucent lithium disilicate glass ceramic products, which comprises

(a) producing a melt of a starting glass containing the following components

2. A process according to claim 1, wherein

(d1) the glass ceramic product in the form of a blank is subjected to plastic shaping at a temperature of 700 to 1200°

C. and by the application of pressure to obtain a glass ceramic product of the desired geometry.

6. A process according to claim 1, wherein the heat treatment in stage (c) is carried out at a temperature of less than 1000°

C.

7. A process according to claim 1, wherein the shaped glass ceramic product of the desired geometry is provided with a coating.

8. A process according to claim 7, wherein the coating is a ceramic, a sintered ceramic, a glass ceramic, a glass, a glaze and/or a composite.

9. A process according to claim 1, wherein the melt of the starting glass contains at least one of the following further components:

10. A process according to claim 9, wherein the quantities of components are selected independently of one another as follows:

11. A process according to claim 9, wherein the colour or fluorescent component used is at least one of the following compounds:

12. A process according to claim 10, wherein the additional components are B₂O₃, Na₂O, BaO, F and/or SrO.

13. A shaped glass ceramic product produced by the process according to claim 1.

14. A glass ceramic product according to claim 13, which has an acid resistance of less than 100 μ

g/cm².

15. A glass ceramic product according to claim 13, which has a CR value of 0.05 to 0.9, measured at a sample thickness of 1.2 mm.

16. A shaped dental restoration, which contains the glass ceramic product according to claim 13.

17. A shaped dental restoration, according to claim 16, which is an inlay, an onlay, a bridge, an abutment, a facing, a veneer, a facet, a crown or a partial crown.

3. A process for the preparation of shaped translucent lithium disilicate glass ceramic products, which comprises

(a) producing a melt of a starting glass containing the following components

4. A process according to claim 3, wherein a blank is used in (d2) which has undergone a heat treatment at 400 to 900°

C. during step (c).

5. A process according to claim 3, wherein the shaped glass ceramic product of the desired geometry obtained in stage (d2) is subjected to at least one further heat treatment.

18. A process according to claim 3, wherein the heat treatment in stage (c) is carried out at a temperature of less than 1000°

C.

19. A process according to claim 3, wherein the shaped glass ceramic product of the desired geometry is provided with a coating.

20. A process according to claim 19, wherein the coating is a ceramic, a sintered ceramic, a glass ceramic, a glass, a glaze and/or a composite.