Method for molding dental restorations and related apparatus

• US 6,818,573 B2
• Filed: 10/19/2002
• Issued: 11/16/2004
• Est. Priority Date: 05/31/1994
• Status: Expired due to Term

• Current Assignee: TEC Ventures, Inc.
• Original Assignee: TEC Ventures, Inc.
• Inventors: Petticrew, Richard W.
• Primary Examiner(s): STEIN, STEPHEN J
• Application Number:
  US10/274,661
• Publication Number:
  US 20030198838A1
• Time in Patent Office: 759 Days
• Field of Search: 501/5, 433/201.1, 433/207.1, 433/212.1, 106/35
• US Class Current: 501/5
• CPC Class Codes: A61C 13/20 Methods or devices for soldering, casting, moulding or melting A61C13/04, A61C13/081 take precedence
• CPC Class Codes: A61K 6/16 Refractive index
• CPC Class Codes: A61K 6/17 Particle size
• CPC Class Codes: A61K 6/78 Pigments
• CPC Class Codes: A61K 6/818 comprising zirconium oxide
• CPC Class Codes: A61K 6/833 Glass-ceramic composites
• CPC Class Codes: B28B 1/24 by injection moulding injection moulding of ceramic slips B28B1/265; of tubular articles B28B21/38
• CPC Class Codes: B28B 5/04 in moulds moved in succession past one or more shaping stations on turn-tables B28B5/06
• CPC Class Codes: C03C 10/0027 containing SiO2, Al2O3, Li2O as main constituents
• CPC Class Codes: C03C 3/097 containing phosphorus, niobium or tantalum
• CPC Class Codes: C03C 4/0021 for dental use

Abstract

The present invention is concerned with a process for the formation of dental restorations from glass-ceramic materials and the resulting dental restorations. A dental restoration is formed by pressing a lithium discilicate glass ceramic where the concentration of lithium discilicate crystals in the glass ceramic composition is at least 30% by weight. Crystal formation is effected with P₂O₅. The glass ceramic material may further contain coloring oxides, fluoresing agents, pigments, opacifiers and glass modifiers. The resulting dental restorations have superior optical, esthetic and strength properties.

Claims

1. A dental restoration which is formed by pressing a lithium disilicate glass ceramic material composition wherein the concentration of lithium disilicate crystals in said glass ceramic composition is at least 30% by weight percent, and wherein the glass ceramic material is pressable and has a softening temperature of at least 850°

C.

2. The dental restoration of claim 1 wherein the glass ceramic material has the following composition by weight percent,

3. A dental restoration of claim 1 wherein the ceramic material has the following composition by Weight percent,

4. The dental restoration of claim 1 wherein the glass ceramic material has the following composition by weight percent;

5. The dental restoration of claim 1 wherein the glass ceramic material has the following composition by weight percent;

6. The dental restoration of claim 1 wherein the glass ceramic material has the following composition by weight percent;

7. The dental restoration of claim 1 wherein the glass ceramic material has the following composition by weight percent;

8. The dental restoration of claim 1 wherein the glass ceramic material has the following composition by weight percent;

9. The dental restoration of claim 1 wherein, prior to pressing a glass ceramic button suitable for pressing is formed by the steps of;

a. melting the components of the glass ceramic to form a glass composition,

b. quenching said glass composition,

c. heat treating the glass composition to convert it into a glass ceramic,

d. grinding said glass ceramic into a powder,

e. modifying the powder with one or more glass modifiers,

f. compacting and sintering the powder into a button,

g. heating the button to a temperature wherein it becomes semi plastic and pressing the button into a preformed mold having a negative cavity in the shape of the desired dental restoration.

10. The dental restoration of claim 2 wherein, prior to pressing a glass ceramic button suitable for pressing is formed by the steps of;

a. melting the components of the glass ceramic to form a glass composition,

b. quenching said glass composition,

c. heat treating the glass composition to convert it into a glass ceramic,

d. grinding said glass ceramic into a powder,

e. modifying the powder with one or more glass modifiers,

f. compacting and sintering the powder into a button,

g. heating the button to a temperature wherein it becomes semi plastic and pressing the button into a preformed mold having a negative cavity in the shape of the desired dental restoration.

11. The dental restoration of claim 3 wherein, prior to pressing, a glass button suitable for pressing is formed by the steps of;

a. melting the components of the glass ceramic to form a glass composition,

b. quenching said glass composition,

c. heat treating the glass composition to convert it into a glass ceramic,

d. grinding said glass ceramic into a powder,

e. modifying the powder with one or more glass modifiers,

f. compacting and sintering the powder into a button,

g. heating the button to a temperature wherein it becomes semi plastic and pressing the button into a preformed mold having a negative cavity in the shape of the desired dental restoration.

12. The dental restoration of claim 4 wherein, prior to pressing, a glass ceramic button suitable for pressing is formed by the steps of;

a. melting the components of the glass ceramic to form a glass composition,

b. quenching said glass composition,

c. heat treating the glass composition to convert it into a glass ceramic,

d. grinding said glass ceramic into a powder,

e. modifying the powder with one or more glass modifiers,

f. compacting and sintering the powder into a button,

g. heating the button to a temperature wherein it becomes semi plastic and pressing the button into a preformed mold having a negative cavity in the shape of the desired dental restoration.

13. The dental restoration of claim 5 wherein, prior to pressing, a glass ceramic button suitable for pressing is formed by the steps of

a. melting the components off the glass ceramic to form a glass composition,

b. quenching said glass composition,

c. heat treating the glass composition to convert it into a glass ceramic,

d. grinding said glass ceramic into a powder,

e. modifying the powder with one or more glass modifiers,

f. compacting and sintering the powder into a button,

g. heating the button to a temperature wherein it becomes semi plastic and pressing the button into a preformed mold having a negative cavity in the shape of the desired dental restoration.

14. The dental restoration of claim 6 wherein, prior to pressing, a glass ceramic button suitable for pressing is formed by the steps of;

a. melting the components of the glass ceramic to form a glass composition,

b. quenching said glass composition,

c. heat treating the glass composition to convert it into a glass ceramic,

d. grinding said glass ceramic into a powder,

e. compacting and sintering the powder into a button,

f. heating the button to a temperature wherein it becomes semi plastic and pressing the button into a preformed mold having a negative cavity in the shape of the desired dental restoration.

15. The dental restoration of claim 7 wherein, prior to pressing, a glass ceramic button suitable for pressing is formed by the steps of;

a. melting the components of the glass ceramic to form a glass composition,

b. quenching said glass composition,

c. heat treating the glass composition to convert it into a glass ceramic,

d. grinding said glass ceramic into a powder,

e. modifying the powder with one or more glass modifiers,

f. compacting and sintering the powder into a button,

g. heating the button to a temperature wherein it becomes semi plastic and pressing the button into a preformed mold having a negative cavity in the shape of the desired dental restoration.

16. The dental restoration of claim 1 wherein, prior to pressing, a glass ceramic button suitable for pressing is formed by the steps of;

a. melting the components of the glass ceramic to form a glass composition,

b. quenching said glass composition,

c. heat treating the glass composition to convert it into a glass ceramic,

d. grinding said glass ceramic into a powder,

e. modifying the powder with one or more glass modifiers,

f. compacting and sintering the powder into a button,

g. heating the button to a temperature wherein it becomes semi plastic and pressing the button into a preformed mold having a negative cavity in the shape of the desired dental restoration.

19. The dental restoration of claim 1 wherein the concentration of lithium disilicate crystals is from about 30 to about 80 weight percent.

20. The dental restoration of claim 1 wherein the concentration of lithium disilicate crystals is from about 40 to about 60 weight percent.

21. The dental restoration of claim 1 wherein the concentration of lithium disilicate crystals is from about 45 to about 55 weight percent.

17. A dental restoration which is formed by the following steps;

a. melting a mixture of metal oxides, which forms a pressable lithium disilicate glass ceramic, to form a glass composition, having a softening temperature of at least 850°

C.

b. quenching said glass composition,

c. heat treating said glass composition to convert it into a glass ceramic,

d. grinding said glass ceramic into a powder,

e. modifying the glass ceramic powder with one or more glass modifiers,

f. compacting and sintering the powder into a button,

g. heating the button to a temperature wherein it becomes semi plastic and,

h. pressing the button into a preformed mold having a negative cavity in the shape of the desired dental restoration.

18. A dental restoration which is formed by the following steps;

a. melting a mixture of metal oxides, which forms a pressable lithium disilicate glass ceramic, to form a glass composition, having a softening temperature of_at least 850°

C.

b. cast a button of said glass composition,

c. heat treating said button to convert it into a glass ceramic,

d. heating the button to a temperature wherein it becomes semi plastic and,

e. pressing the button into a preformed mold having a negative cavity in the shape of the desired dental restoration.