Low temperature-sintering apatite glass ceramic

• US 20020022563A1
• Filed: 06/22/2001
• Published: 02/21/2002
• Est. Priority Date: 06/28/2000
• Status: Active Grant

• Current Assignee: Ivoclar Vivadent AG
• Original Assignee: Ivoclar Vivadent AG
• Inventors: Rheinberger, Volker, Schweiger, Marcel, Holand, Wolfram
• Granted Patent: US 6,620,747 B2
• Time in Patent Office: Days
• US Class Current: 501/3
• CPC Class Codes: A61K 6/17 Particle size
• CPC Class Codes: A61K 6/20 Protective coatings for natural or artificial teeth, e.g. sealings, dye coatings or varnish
• CPC Class Codes: A61K 6/75 Apatite
• CPC Class Codes: A61K 6/807 comprising magnesium 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 6/827 Leucite
• CPC Class Codes: A61K 6/833 Glass-ceramic composites
• CPC Class Codes: C03C 10/0027 containing SiO2, Al2O3, Li2O as main constituents
• CPC Class Codes: C03C 10/16 Halogen containing crystalline phase
• CPC Class Codes: C03C 4/0021 for dental use

Abstract

A low-temperature-sintering apatite glass ceramic is described which is characterized by a high chemical stability, a low coefficient of expansion as well as high translucency and which is particularly suitable on its own or together with glasses or other glass ceramics as coating or veneering material for ceramic dental restorations.

Claims

1. Low-temperature-sintering glass ceramic, which comprises the following components:

2. Apatite glass ceramic according to claim 1, which comprises at least one of the following components:

3. Apatite glass ceramic according to claim 1 or 2, wherein the amounts of the components, unless otherwise stated, are independently of each other as follows:

4. Apatite glass ceramic according to any one of claims 1 to 3, wherein the amounts of the components are independently of each other as follows:

5. Apatite glass ceramic according to any one of claims 1 to 4, which has a sintering temperature of less than 800°

C.

6. Apatite glass ceramic according to any one of claims 1 to 5, which has a sintering temperature from 670 to 780°

C.

7. Apatite glass ceramic according to any one of claims 1 to 6, wherein the apatite crystals are needle-shaped.

8. Apatite glass ceramic according to any one of claims 1 to 7, wherein the apatite crystals are smaller than 10 μ

m at their greatest extension.

9. Apatite glass ceramic according to any one of claims 1 to 8, which has a linear thermal coefficient of expansion of 9.3 to 10.8×

10<sup>−

6</sup>K<sup>−

1</sup>, measured in the temperature range of 100°

C. to 400°

C.

10. Process for preparing the apatite glass ceramic according to any one of claims 1 to 9, comprising the following steps

a) a starting glass which comprises the components according to any one of claims 1 to 4 is melted at temperatures of 1200°

C. to 1650°

C.,

b) the obtained glass melt is poured into water to form a glass granulate,

c) the glass granulate is optionally reduced to produce a glass powder with an average particle size of 1 to 450 μ

m, relative to the number of particles, and

d) the glass granulate or the glass powder is subjected to a thermal treatment at more than 500°

C. and up to 900°

C. for a period of 30 minutes to 6 hours.

11. Dental material, which comprises the apatite glass ceramic according to any one of claims 1 to 9.

12. Dental material according to claim 11, which additionally comprises a potassium-zinc-silicate glass.

13. Dental material according to claim 12, wherein the potassium-zinc-silicate glass comprises the following components:

14. Dental material according to any one of claims 11 to 13, which has a sintering temperature of less than 800°

C.

15. Use of the dental material according to any one of claims 11 to 14 for coating a substrate and in particular for coating a dental restoration.

16. Use according to claim 15, wherein a substrate based on ceramic or glass ceramic material, in particular lithium disilicate glass ceramic, is used.

17. Use according to claim 16, wherein the lithium disilicate glass ceramic comprises the following components:

18. Use according to any one of claims 15 to 17, wherein the dental material is applied to the substrate and sintered at temperatures of less than 800°

C.

19. Shaped dental product, which comprises the apatite glass ceramic according to any one of claims 1 to 9 or the dental material according to any one of claims 11 to 14.

20. Shaped dental product according to claim 19, which is a dental restoration.

21. Shaped dental product according to claim 19 or 20, which has a core based on ceramic or glass ceramic material and a coating applied to it comprising the apatite glass ceramic or the dental material.

22. Shaped dental product according to claim 21, wherein the glass ceramic material is a lithium disilicate glass ceramic.