Glass for dental applications
The invention relates to a glass for dental applications which can be used as a glazing material of dental restorations and resists high temperatures, and thus does not tend to flow.
1. A composition consisting of a glass comprising the following components, in weight percent:
SiO 2
60.0-65.0%
K 2 O
15.0-19.0%
Al 2 O 3
6.0-10.5%
Li 2 O
1.8-2.2%
Me II O
2.5-8.5%
further oxides
1.5-7.0%
wherein
(a) Me″O represents at least one divalent oxide which is selected from the group of the oxides of Ca, Mg, Sr and Zn, wherein ZnO is present in an amount less than 2.0%, and
(b) further oxides represents at least one oxide which is selected from the group of the oxides of B, Zr, Ce and Y; and
wherein the glass has a linear coefficient of thermal expansion of 8.0 to 9.5×10 −6 K −1 in the temperature range of 100 to 500° C.
2. The composition according to claim 1 , wherein the glass essentially consists of the components.
3. The composition according to claim 1 , wherein the glass comprises at least one of the components in the following quantity(s), in weight percent:
SiO 2
63.0-65.0%
K 2 O
17.0-19.0%
Al 2 O 3
9.5-10.5%
Li 2 O
1.9-2.1%
Me II O
4.5-7.5%
further oxides
2.5-6.0%.
4. The composition according to claim 1 , wherein the glass further comprises 0.5 to 2.5 wt.-% ZrO 2 .
5. The composition according to claim 1 , wherein the glass further comprises 15.5 to 19.0 wt.-% K 2 O.
6. The composition according to claim 5 , wherein the glass comprises 17.5-19.0 wt.-% K 2 O.
7. The composition according to claim 1 , wherein the glass comprises at least one of the components in the following amount(s), in weight percent:
SiO 2
64.0-65.0%
K 2 O
18.0-18.5%
Al 2 O 3
10.0-10.5%
Li 2 O
2.0-2.1%
MgO
0.4-2.1%
CaO
1.9-2.3%
ZrO 2
1.0-2.4%
CeO 2
0.4-0.8%.
8. The composition according to claim 7 , wherein the glass comprises at least one of the components in the following amount(s), in weight percent:
MgO
0.4-0.7%
CaO
1.9-2.1%
ZrO 2
2.0-2.4%.
9. The composition according to claim 1 , having a firing temperature of 900 to 950° C.
10. The composition according to claim 9 , having a liring temperature of910° C. to 930° C.
11. The composition according to claim 1 , which has a linear coefficient of thermal expansion of8.4 to 9.1×10 −6 K −1 in the temperature range of 100 to 500° C.
12. A glazing material for dental restorations comprising the composition of claim 1 .
13. In combination, the glazing material of claim 12 , and a dental restoration, wherein the dental restoration is a bridge, a crown, an inlay, an onlay, a veneer, a cap, or a part thereof.
14. The combination according to claim 13 , wherein the dental restoration comprises a glass, a ceramic, a metal or a glass-ceramic framework.
15. The combination according to claim 14 , wherein the glass-ceramic is a lithium silicate glass-ceramic, a mica glass-ceramic or a chondrodite glass-ceramic.
16. The combination according to claim 15 , wherein the lithium silicate glass-ceramic is a lithium metasilicate or a lithium disilicate glass-ceramic.
17. A process of applying a glaze onto a dental restoration, the process comprising:
(a) applying the composition according to claim 1 onto the dental restoration; and
(b) thermally treating the dental restoration and the applied composition in a manner which transforms the glass into a glaze that adheres firmly to the restoration.
18. The process according to claim 17 , wherein the thermal treatment takes place at a temperature of at least 860° C.
19. The process according to claim 18 , wherein the thermal treatment takes place at a temperature of 860° C.-960° C.
20. The process according to claim 17 , wherein the dental restoration is based on a glass, a ceramic, a metal or a glass-ceramic.
21. The process according to claim 20 , wherein the thermal treatment also leads to the formation of crystals in the glass or the glass-ceramic.
22. The process according to claim 21 , wherein the thermal treatment leads to the formation of lithium disilicate crystals or mica crystals.
23. The process according to claim 21 , in which the formation of crystals brings about an increase in the strength of the dental restoration.
24. The glazing material according to claim 12 further comprising a glaze, a staining dye or a mixture thereof.
25. The process according to claim 17 wherein the composition of step (a) is mixed with a glaze, a staining dye or a mixture thereof prior to applying onto the dental restoration.
26. A glazing material for dental restorations comprising the following components, in weight percent:
SiO 2
60.0-65.0%
K 2 O
15.0-19.0%
Al 2 O 3
6.0-10.5%
Li 2 O
1.8-2.2%
Me II O
2.5-8.5%
further oxides
1.5-7.0%
wherein
(a) Me″O represents at least one divalent oxide which is selected from the group of the oxides of Ca, Mg, Sr and Zn, wherein ZnO is present in an amount less than 2.0%: and
(b) further oxides represents at least one oxide which is selected from the group of the oxides of B, Zr, Ce and Y; and
wherein the glass has a linear coefficient of thermal expansion of 8.0 to 9.5×10 −6 K −1 in the temperature range of 100 to 500° C.
27. In combination, the glazing material of claim 26 , and a dental restoration, wherein the dental restoration is a bridge, a crown, an inlay, an onlay, a veneer, a cap, or a part thereof.
28. The combination according to claim 27 , wherein the dental restoration comprises a glass, a ceramic, a metal or a glass-ceramic framework.
29. The combination according to claim 28 , wherein the glass-ceramic is a lithium silicate glass-ceramic, a mica glass-ceramic or a chondrodite glass-ceramic.
30. The combination according to claim 29 , wherein the lithium silicate glass-ceramic is a lithium metasilicate or a lithium disilicate glass-ceramic.
31. The glazing material according to claim 26 further comprising a glaze, a staining dye or a combination thereof.
32. A process of applying a glaze onto a dental restoration, the process comprising:
(a) applying onto the dental restoration; the composition comprising the following components, in weight percent:
SiO 2
60.0-65.0%
K 2 O
15.0-19.0%
Al 2 O 3
6.0-10.5%
Li 2 O
1.8-2.2%
Me II O
2.5-8.5%
further oxides
1.5-7.0%
wherein
(i) Me″O represents at least one divalent oxide which is selected from the group of the oxides of Ca, Mg, Sr and Zn, wherein ZnO is present in an amount less than 2.0%: and
(ii) further oxides represents at least one oxide which is selected from the group of the oxides of B, Zr, Ce and Y; and
wherein the glass has a linear coefficient of thermal expansion of 8.0 to 9.5×10 −6 K 31 in the temperature range of 100 to 500° C.; and
(b) thermally treating the dental restoration and the applied composition in a manner which transforms the glass into a glaze that adheres firmly to the restoration.
33. The process according to claim 32 . wherein the thermal treatment takes place at a temperature of at least 860° C.
34. The process according to claim 33 , wherein the thermal treatment takes place at a temperature of 860° C.-960° C.
35. The process according to claim 32 , wherein the dental restoration is based on a glass, a ceramic, a metal or a glass-ceramic.
36. The process according to claim 35 . wherein the thermal treatment also leads to the formation of crystals in the glass or the glass-ceramic.
37. The process according to claim 36 , wherein the thermal treatment leads to the formation of lithium disilicate crystals or mica crystals.
38. The process according to claim 36 , in which the formation of crystals brings about an increase in the strength of the dental restoration.
39. The process according to claim 32 wherein the composition of step (a) is mixed with a glaze, a staining dye or a mixture thereof prior to applying onto the dental restoration.