Patent US4515634A successfully refreshed from Google Patents.
US4515634A
Expired / Lapsed
US
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Castable glass-ceramic composition useful as dental restorative
Assignee: Dentsply Sirona Inc
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Filing: 1983-10-17
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Granted: 1985-05-07
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Expires: 2003-10-17
Abstract
Abstract A glass ceramic, useful in making dental crowns and bridges, consisting essentially of: - Broad Range, Preferred -Component Mole Percent Mole % -Li2O 24-33 29.5 +/- 1 -SiO2 37-74.3 59.0 +/- 3,-2 -Al2O3 0.5-4 1.5 +/- 0.5 -CaO 1-10 6.0 +/- 1 -P2O5 0.2-4 2.0 + 0.5,-1 -TiO 0-4 1.0 +/- 0.5 -ZrO2 0-4 1.0 +/- 0.5 -MgO 0-2 - -K2O 0-2 - -
Inventors
- 👤 Jenn-Ming Wu
- 👤 Warren R. Cannon
- 👤 Carlino Panzera
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 15:06
CPC Classifications
C; C03; C03C; C03C4/00; C03C4/0007; C03C4/0021; A; A61; A61K; A61K6/00; A61K6/80; A61K6/802; A61K6/807; A61K6/816; A61K6/818; A61K6/824; A61K6/831; A61K6/833; C03C10/00; C03C10/0018; C03C10/0027
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
76 words
A glass-ceramic having high strength and a high softening temperature, consisting essentially of the following constituents, on a mole percent basis: ______________________________________
Li.sub.2 O 28.5-30.5
SiO.sub.2 57-62
Al.sub.2 O.sub.3
1-2
CaO 5-7
P.sub.2 O.sub.5
1-2.5
TiO.sub.2 0.5-1.5
ZrO.sub.2 0.5-1.5
______________________________________ wherein the crystalline phase is lithium disilicate, said glass ceramic having a flexural strength of from about 40,000 psi to about 52,000 psi, and a softening temperature of from about 750° C. to about 825° C.
Claim 2
Dependent Claim
76 words
A glass-ceramic having high strength and a high softening temperature, consisting essentially of the following constituents, on a mole percent basis: ______________________________________
Li.sub.2 O 28.5-30.5
SiO.sub.2 57-62
Al.sub.2 O.sub.3
1-2
CaO 5-7
P.sub.2 O.sub.5
1-2.5
TiO.sub.2 0.5-1.5
ZrO.sub.2 0.5-1.5
______________________________________ wherein the crystalline phase is lithium disilicate, said glass ceramic having a flexural strength of from about 40,000 psi to about 52,000 psi, and a softening temperature of from about 750° C. to about 825° C.
Claim 3
Dependent Claim
9 words
A dental restoration comprising the glass-ceramic of claim 1.
Claim 4
Dependent Claim
33 words
The glass-ceramic of claim 1 having the following composition, on a mole percent basis: ______________________________________
Li.sub.2 O
29.5
SiO.sub.2
59.0
Al.sub.2 O.sub.3
1.5
CaO 6.0
P.sub.2 O.sub.5
2.0
TiO.sub.2
1.0
ZrO.sub.2
1.0
______________________________________
Claim 5
Dependent Claim
9 words
A dental restoration comprising the glass-ceramic of claim 3.
References Cited (Backward Citations)
US3282712A
Cited
US3809543A
Cited
US3816704A
Cited
JPS49126712A
Cited
US3977857A
Cited
US4189325A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-05-06 | 1988-11-05 | 1989-05-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-05-06 | 1992-11-05 | 1993-05-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-05-06 | 1996-11-05 | 1997-05-07 | $7700.00 | Window Closed / Lapsed |