Lithium disilicate glass ceramics

• US 6,517,623 B1
• Filed: 08/17/2000
• Issued: 02/11/2003
• Est. Priority Date: 12/11/1998
• Status: Expired due to Term

• Current Assignee: Ardent, Inc. (Ivoclar Vivadent AG)
• Original Assignee: Jeneric/Pentron Incorporated (Danaher Corporation)
• Inventors: Panzera, Carlino, Brodkin, Dmitri, Panzera, Paul
• Primary Examiner(s): KOSLOW, CAROL M
• Application Number:
  US09/640,941
• Time in Patent Office: 908 Days
• Field of Search: 264/16, 264/19, 501/5, 106/35, 433/201.1, 433/202.2, 433/212.1
• US Class Current: 106/35
• 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 6/824 comprising transition metal oxides
• 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: C03B 32/02 Thermal crystallisation, e.g. for crystallising glass bodies into glass-ceramic articles C03B27/012 takes precedence
• CPC Class Codes: C03C 10/0027 containing SiO2, Al2O3, Li2O as main constituents
• CPC Class Codes: C03C 4/0021 for dental use

Abstract

This invention is directed to lithium disilicate (Li₂Si₂O₅) based glass-ceramics comprising silica, lithium oxide, alumina, potassium oxide and phosphorus pentoxide. The glass-ceramics are useful in the fabrication of single and multi-unit dental restorations (e.g. anterior bridges) made by heat pressing into refractory investment molds produced using lost wax techniques. The glass-ceramics have good pressability, i.e., the ability to be formed into dental articles by heat-pressing using commercially available equipment. In accordance with one embodiment directed to the process of making the glass-ceramics, the compositions herein are melted at about 1200° to about 1600° C., thereafter quenched (e.g., water quenched or roller quenched) or cast into steel molds, or alternately, cooled to the crystallization temperature. The resulting glass is heat-treated to form a glass-ceramic via a one or two step heat-treatment cycle preferably in the temperature range of about 400° to about 1100° C. The resulting glass ceramics are then pulverized into powder and used to form pressable pellets and/or blanks of desired shapes, sizes and structures which are later pressed into dental restorations. Alternatively, instead of forming into pressable pellets or blanks, the pulverized powder is used to form a dental restoration using the refractory die technique or platinum foil technique.

Claims

1. A dental restoration comprising in weight percent:

about 62 to about 85% SiO₂;

about 1.5 to about 10% Al₂O₃;

about 8 to about 19% Li₂O;

about 2.5 to about 7% K₂O;

about 0.5 to about 12% P₂O₅;

up to about 7% CaO;

up to about 5% ZnO;

up to about 1% SrO;

up to about 5% Na₂O;

up to about 7% BaO; and

wherein the molar ratio of (Na₂O+K₂O+CaO+SrO+BaO)/(Al₂O₃+ZnO)≧

1.3.

2. The dental restoration of claim 1 manufactured from a glass-ceramic that is pressable.

3. The dental restoration of claim 1 further comprising in weight percent:

up to about 4.9% B₂O₃;

up to about 1.5% F;

up to about 2% MgO;

up to about 5% Cs₂O;

up to about 2% TiO₂;

up to about 3% ZrO₂;

up to about 1% SnO₂;

up to about 1% Sb₂O₃;

up to about 3% Y₂O₃;

up to about 1% CeO₂;

up to about 1% Eu₂O₃;

up to about 1% Tb₄O₇;

up to about 2% Nb₂O₅; and

up to about 2% Ta₂O₅.

4. The dental restoration of claim 1 formed into a component selected from orthodontic appliances, bridges, space maintainers, tooth replacement appliances, splints, crowns, partial crowns, dentures, posts, teeth, jackets, inlays, onlays, facing, veneers, facets, implants, abutments, cylinders, and connector.

5. The dental restoration of claim 1 manufactured from a blank of glass ceramic material.

6. The dental restoration of claim 1 manufactured from a glass-ceramic formable powder.

7. A glass-ceramic composition comprising in weight percent:

about 64 to about 70% SiO₂;

about 1.5 to about 6 Al₂O₃;

about 10 to about 15% Li₂O;

about 2.5 to about 5% K₂O;

about 2 to about 7% P₂O₅;

up to about 7% BaO;

up to about 1% SrO;

up to about 2% ZnO;

up to about 0.9% CaO;

up to about 3% Na₂O; and

wherein the molar ratio of (Na₂O+K₂O+CaO+SrO+BaO)/(Al₂O₃+ZnO)≧

1.3.

8. The glass-ceramic composition of claim 7 whereby the glass-ceramic is pressable.

9. The glass-ceramic composition of claim 7 further comprising in weight percent:

up to about 1.5% F;

up to about 5% Cs₂O;

up to about 2.7% B₂O₃;

up to about 2% MgO;

up to about 2% TiO₂;

up to about 3% ZrO₂;

up to about 1% SnO₂;

up to about 1% Sb₂O₃;

up to about 3% Y₂O₃;

up to about 1% CeO₂;

up to about 1% Eu₂O₃;

up to about 1% Tb₄O₇;

up to about 2% Nb₂O₅; and

up to about 2% Ta₂O₅.

10. A dental restoration comprising the glass-ceramic of claim 7.

11. A glass-ceramic composition comprising in weight percent:

about 62 to about 85% SiO₂;

about 5.1 to about 10 Al₂O₃;

about 8 to about 19% Li₂O;

about 0.5 to about 12% P₂O₅;

up to about 5% Na₂O;

up to about 7% K₂O;

up to about 7% CaO;

up to about 1% SrO;

up to about 7% BaO;

up to about 5% ZnO; and

wherein the molar ratio of (Na2O+K₂O+CaO+SrO+BaO)/(Al₂O₃+ZnO)≧

1.3.

12. The glass-ceramic composition of claim 11 whereby the glass-ceramic is pressable.

13. The glass-ceramic composition of claim 11 further comprising in weight percent:

up to about 1.5% F;

up to about 5% Cs₂O;

up to about 4.9% B₂O₃;

up to about 2% MgO;

up to about 2% TiO₂;

up to about 3% ZrO₂;

up to about 1% SnO₂;

up to about 1% Sb₂O₃;

up to about 3% Y₂O₃;

up to about 1% CeO₂;

up to about 1% Eu₂O₃;

up to about 1% Tb₄O₇;

up to about 2% Nb₂O₅; and

up to about 2% Ta₂O₅.

14. A dental restoration comprising the glass-ceramic of claim 11.

15. A glass-ceramic composition comprising in weight percent:

about 64 to about 70% SiO₂;

about 5.2 to about 9 Al₂O₃;

about 10 to about 15% Li₂O;

about 2 to about 7% P₂O₅;

up to about 3% Na₂O;

up to about 5% K₂O;

up to about 0.9% CaO;

up to about 1% SrO;

up to about 7% BaO;

up to about 2% ZnO; and

wherein the molar ratio of (Na₂O+K₂O+CaO+SrO+BaO)/(Al₂O₃+ZnO)≧

1.3.

16. The glass-ceramic composition of claim 15 whereby the glass-ceramic is pressable.

17. The glass-ceramic composition of claim 15 further comprising in weight percent:

up to about 1.5% F;

up to about 5% Cs₂O;

up to about 2.7% B₂O₃;

up to about 2% MgO;

up to about 2% TiO₂;

up to about 3% ZrO₂;

up to about 1% SnO₂;

up to about I% Sb₂O₃;

up to about 3% Y₂O₃;

up to about 1% CeO₂;

up to about 1% Eu₂O₃;

up to about 1% Tb₄O₇;

up to about 2% Nb₂O₅; and

up to about 2% Ta₂O₅.

18. A dental restoration comprising the glass-ceramic of claim 15.

19. A glass-ceramic composition comprising in weight percent:

about 64 to about 70% SiO₂;

about 1.5 to about 6 Al₂O₃;

about 10 to about 15% Li₂O;

about 2 to about 7% P₂O₅;

about 2.2 to about 5% K₂O;

about 0.5 to about 3% Na₂O;

about 0.5 to about 3% B₂O₃;

up to about 0.9% CaO;

up to about 1% SrO;

up to about 7% BaO;

wherein the molar ratio of (Na₂O+K₂O+CaO+SrO+BaO)/(Al₂O₃)≧

1.3.

20. The glass-ceramic composition of claims 19 whereby the glass-ceramic is pressable.

21. The glass-ceramic composition of claims 19 further comprising in weight percent:

up to about 1.5% F;

up to about 5% Cs₂O;

up to about 2% TiO₂;

up to about 3% ZrO₂;

up to about 1% SnO₂;

up to about 1% Sb₂O₃;

up to about 3% Y₂O₃;

up to about 1% CeO₂;

up to about 1% Eu₂O₃;

up to about 1% Tb₄O₇;

up to about 2% Nb₂O₅; and

up to about 2% Ta₂O₅.

22. A dental restoration comprising the glass-ceramic of claim 19.

23. A glass-ceramic composition comprising in weight percent:

about 62 to about 76% SiO₂;

about 1.5 to about 10 Al₂O₃;

about 8 to about 19% Li₂O;

about 0.3 to about 7% P₂O₅;

about 0.5 to about 8% Ta₂O₅;

up to about 5% Na₂O;

up to about 7% K₂O;

up to about 7% CaO;

up to about 1% SrO;

up to about 7% BaO;

up to about 5% ZnO;

wherein the molar ratio of (Na₂O+K₂O+CaO+SrO+BaO)/(ZnO+Al₂O₃)≧

1.3.

24. The glass-ceramic composition of claim 23 whereby the glass-ceramic is pressable.

25. The glass-ceramic composition of claim 23 further comprising in weight percent:

up to about 5% B₂O₃.

up to about 1.5% F;

up to about 2% MgO;

up to about 5% Cs₂O;

up to about 2% TiO₂;

up to about 3% ZrO₂;

up to about 1% SnO₂;

up to about 1% Sb₂O₃;

up to about 3% Y₂O₃;

up to about 1% CeO₂;

up to about 1% Eu₂O₃;

up to about 1% Tb₄O₇; and

up to about 2% Nb₂O₅.

26. A dental restoration comprising the glass-ceramic of claim 23.

27. A method of making a lithium disilicate dental restoration comprising:

melting a starting glass composition at temperatures within the range of about 1200 to about 1600°

C.;

quenching the glass melt;

subjecting the quenched glass to one or more heat treatments in the temperature range of from about 400°

to about 1100°

C. to convert the glass into a glass-ceramic;

comminuting the glass ceramic to a powder;

forming the powder onto a die to form a dental restoration; and

sintering the formed dental restoration.

28. The method of claim 27 wherein the glass-ceramic composition comprises:

about 62 to about 85% SiO₂;

about 1.5 to about 10% Al₂O₃;

about 8 to about 19% Li2O;

about 0.5 to about 12% P₂O₅;

up to about 7% CaO;

up to about 5% ZnO;

up to about 1% SrO;

up to about 5% Na₂O;

up to about 7% BaO; and

wherein the molar ratio of (Na₂O+K₂O+CaO+SrO+BaO)/(Al₂O₃+ZnO)≧

1.3.

29. The method of claim 27 wherein the glass-ceramic composition comprises:

about 64 to about 70% SiO₂;

about 1.5 to about 6 Al₂O₃;

about 10 to about 15% Li₂O;

about 2.5 to about 5% K₂O;

about 2 to about 7% P₂O₅;

up to about 7% BaO;

up to about 1% SrO;

up to about 2% ZnO;

up to about 0.9% CaO;

up to about 3% Na₂O; and

wherein the molar ratio of (Na₂O+K₂O+CaO+SrO+BaO)/(Al₂O₃+ZnO)≧

1.3.

30. The method of claim 27 wherein the glass-ceramic composition comprises:

about 62 to about 85% SiO₂;

about 5.1 to about 10 Al₂O₃;

about 8 to about 19% Li₂O;

about 0.5 to about 12 % P₂O₅;

up to about 5% Na₂O;

up to about 7% K₂O;

up to about 7% CaO;

up to about 1% SrO;

up to about 7% BaO;

up to about 5% ZnO; and

wherein the molar ratio of (Na₂O+K₂O+CaO+SrO+BaO)/(Al₂O₃+ZnO)≧

1.3.

31. The method of claim 27 wherein the glass-ceramic composition comprises:

about 64 to about 70% SiO₂;

about 5.2 to about 9 Al₂O₃;

about 10 to about 15% Li₂O;

about 2 to about 7% P₂O₅;

up to about 3% Na₂O;

up to about 5% K₂0;

up to about 0.9% CaO;

up to about 1% SrO;

up to about 7% BaO;

up to about 2% ZnO; and

wherein the molar ratio of (Na₂O+K₂O+CaO+SrO+BaO)/(Al₂O₃+ZnO)≧

1.3.

32. The method of claim 27 wherein the glass-ceramic composition comprises:

about 64 to about 70% SiO₂;

about 1.5 to about 6 Al₂O₃;

about 10 to about 15% Li₂O;

about 2 to about 7% P₂O₅;

about 2.2 to about 5% K₂O;

about 0.5 to about 3% Na₂O;

about 0.5 to about 3% B₂O₃;

up to about 0.9% CaO;

up to about 1 % SrO;

up to about 7% BaO; and

wherein the molar ratio of (Na₂O+K₂O+CaO+SrO+BaO)/(Al₂O₃)≧

1.3.

33. The method of claim 27 wherein the glass-ceramic composition comprises:

about 62 to about 76% SiO₂;

about 1.5 to about 10 Al₂O₃;

about 8 to about 19% Li₂O;

about 0.3 to about 7% P₂O₅;

about 0.5 to about 8% Ta₂O₅;

up to about 5% Na₂O;

up to about 7% K₂O;

up to about 7% CaO;

up to about 1% SrO;

up to about 7% BaO;

up to about 5% ZnO; and

wherein the molar ratio of (Na₂O+K₂O+CaO+SrO+BaO)/(ZnO+Al₂O₃)≧

1.3.