US4455383A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Single-frit glass ceramic
Assignee: Dentsply Sirona Inc
•
Filing: 1983-04-04
•
Granted: 1984-06-19
•
Expires: 2003-04-04
Abstract
Abstract There is disclosed a single-frit porcelain powder, suitable for use as a porcelain layer on metal-base dental restorations, and having a fired coefficient of thermal expansion within the range of from about 12 to about 14x10-6 in./in. DEG C., wherein said single frit porcelain is of the following composition: -Component Weight Percent -SiO2 651/2 +/- 4 -Al2O3 15 +/- 2 -K2O 121/2 - 1, + 2 -Flux 4 +/- 1 -MO 2 +/- 1 - wherein M represents calcium, magnesium, or a mixture thereof, and Flux represents sodium oxide or lithium oxide, or a mixture thereof, and, optionally, may also contain boron oxide.
Inventors
- 👤 Carlino Panzera
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 03:58
CPC Classifications
C; C03; C03C; C03C3/00; C03C3/04; C03C3/076; C03C3/083; C03C3/085; A; A61; A61K; A61K6/00; A61K6/20; A61K6/70; A61K6/78; A61K6/80; A61K6/802; A61K6/807; A61K6/84; C03C3/087; C03C8/00; C03C8/02
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
101 words
A single-frit porcelain powder, suitable for use as a porcelain layer on metal-base dental restorations, and having a fired coefficient of thermal expansion within the range of from about 12 to about 14×10 -6 in/in °C., wherein said single frit porcelain is of the following composition: ______________________________________
Component Weight Percent
______________________________________
SiO.sub.2 651/2 ± 4
Al.sub.2 O.sub.3 15 ± 2
K.sub.2 O 121/2 - 1, + 2
Flux 4 ± 1
MO 2 ± 1
______________________________________ wherein M represents calcium, magnesium, or a mixture thereof, and Flux represents sodium oxide or lithium oxide or a mixture thereof, optionally with boron oxide.
Claim 2
Dependent Claim
101 words
A single-frit porcelain powder, suitable for use as a porcelain layer on metal-base dental restorations, and having a fired coefficient of thermal expansion within the range of from about 12 to about 14×10 -6 in/in °C., wherein said single frit porcelain is of the following composition: ______________________________________
Component Weight Percent
______________________________________
SiO.sub.2 651/2 ± 4
Al.sub.2 O.sub.3 15 ± 2
K.sub.2 O 121/2 - 1, + 2
Flux 4 ± 1
MO 2 ± 1
______________________________________ wherein M represents calcium, magnesium, or a mixture thereof, and Flux represents sodium oxide or lithium oxide or a mixture thereof, optionally with boron oxide.
Claim 3
Dependent Claim
52 words
The porcelain powder of claim 1 wherein the procelain powder has the following composition: ______________________________________
Component Weight Percent
______________________________________
SiO.sub.2 651/2 ± 1
Al.sub.2 O.sub.3 15 ± 1
K.sub.2 O 12 ± 1
Flux 4 ± 1
MO 2 ± 1/2
______________________________________ wherein Flux and M are as defined in claim 1.
Claim 4
Dependent Claim
28 words
The porcelain powder of claim 2 wherein the Flux contains 22/3±1/3 weight percent sodium oxide and 11/4±1/4 weight percent lithium oxide, percentages being based upon weight of porcelain.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-06-19 | 1987-12-19 | 1988-06-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-06-19 | 1991-12-19 | 1992-06-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-06-19 | 1995-12-19 | 1996-06-19 | $7700.00 | Window Closed / Lapsed |