US4198244A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fluorescing agents for dental porcelain
Assignee: National Research Development Corp UK
•
Filing: 1978-04-07
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Granted: 1980-04-15
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Expires: 1998-04-07
Abstract
Abstract A dental porcelain composition which includes, as fluorescing agents, 0.05 to 2% by weight of CeO2 and 0.1 to 0.5% by weight of Tb2O3.
Inventors
- 👤 David B. Binns
- 👤 Ian K. Bloor
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 11:08
CPC Classifications
C; C04; C04B; C04B33/00; C04B33/24; A; A61; A61K; A61K6/00; A61K6/15; A61K6/17; A61K6/70; A61K6/78; A61K6/80; A61K6/802; A61K6/822; A61K6/824; C09; C09K; C09K11/00; C09K11/08; C09K11/77; C09K11/7766; C09K11/7767; C09K11/7769
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
38 words
A dental porcelain composition, comprising dental procelain and, as fluorescing agents, from 0.05 to 2% by weight CeO 2 and from 0.1 to 0.5% by weight of Tb 2 O 3 based on the weight of the procelain.
Claim 2
Dependent Claim
38 words
A dental porcelain composition, comprising dental procelain and, as fluorescing agents, from 0.05 to 2% by weight CeO 2 and from 0.1 to 0.5% by weight of Tb 2 O 3 based on the weight of the procelain.
Claim 3
Dependent Claim
20 words
The porcelain composition of claim 1 which includes about 0.1% CeO 2 and about 0.25% Tb 2 O 3 .
Claim 4
Dependent Claim
64 words
A dental porcelain composition as claimed in claim 1 or 2 which additionally includes one or more of the fluorescent oxides: ______________________________________
Dy.sub.2 O.sub.3
in an amount up to 0.1% by weight,
V.sub.2 O.sub.5
in an amount up to 0.1% by weight,
Sm.sub.2 O.sub.3
in an amount up to 0.2% by weight and
Eu.sub.2 O.sub.3
in an amount up to 0.2% by weight.
______________________________________
Claim 5
Independent Claim
69 words
A method for preparing a dental porcelain composition which fluoresces under ultraviolet radiation comprising melting a dental porcelain at a temperature of at least 1200° C., adding to the resulting melt and thoroughly disbursing therein from 0.05 to 2% by weight of CeO 2 and from 0.1 to 0.5% by weight Tb 2 O 3 based on the weight of the procelain and thereafter allowing the melt to cool.
Claim 6
Independent Claim
69 words
A method for preparing a dental porcelain composition which fluoresces under ultraviolet radiation comprising melting a dental porcelain at a temperature of at least 1200° C., adding to the resulting melt and thoroughly disbursing therein from 0.05 to 2% by weight of CeO 2 and from 0.1 to 0.5% by weight Tb 2 O 3 based on the weight of the procelain and thereafter allowing the melt to cool.
Claim 7
Dependent Claim
15 words
The method of claim 4 in which the dental porcelain is melted at 1400° C.
Claim 8
Independent Claim
70 words
A method for preparing a dental porcelain composition which fluoresces under ultraviolet light comprising melting a dental porcelain at a temperature of at least 1200° C., mixing with the porcelain prior to melting or during melting from 0.05 to 2% by weight of CeO 2 and from 0.1 to 0.5% by weight Tb 2 O 3 based on the weight of the porcelain and thereafter allowing the melt to cool.
Claim 9
Independent Claim
70 words
A method for preparing a dental porcelain composition which fluoresces under ultraviolet light comprising melting a dental porcelain at a temperature of at least 1200° C., mixing with the porcelain prior to melting or during melting from 0.05 to 2% by weight of CeO 2 and from 0.1 to 0.5% by weight Tb 2 O 3 based on the weight of the porcelain and thereafter allowing the melt to cool.
Claim 10
Dependent Claim
15 words
The method of claim 6 in which the dental porcelain is melted at 1500° C.
Claim 11
Independent Claim
31 words
A method as claimed in any one of claims 4, 5, 6 or 7 in which 0.1% by weight CeO 2 and 0.25% by weight Tb 2 O 3 are used.
Claim 12
Independent Claim
69 words
A method as claimed in any one of claims 4, 5, 6 or 7 in which one or more of the fluorescent oxides: ______________________________________
Dy.sub.2 O.sub.3
in an amount up to 0.1% by weight,
V.sub.2 O.sub.5
in an amount up to 0.1% by weight,
Sm.sub.2 O.sub.3
in an amount up to 0.2% by weight, and
Eu.sub.2 O.sub.3
in an amount up to 0.2% by weight
______________________________________ are additionally used.
Claim 13
Dependent Claim
20 words
A dental porcelain when prepared by a method as claimed in any one of claims 4, 5, 6 or 7.
Claim 14
Dependent Claim
23 words
The dental porcelain of claim 10, in which 0.1% by weight CeO 2 and 0.25% by weight Tb 2 O 3 are used.
Claim 15
Dependent Claim
61 words
The dental porcelain of claim 10, in which one or more of the fluorescent oxides: ______________________________________
Dy.sub.2 O.sub.3
in an amount up to 0.1% by weight,
V.sub.2 O.sub.5
in an amount up to 0.1% by weight,
Sm.sub.2 O.sub.3
in an amount up to 0.2% by weight, and
Eu.sub.2 O.sub.3
in an amount up to 0.2% by weight
______________________________________ are additionally used.
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) | 1983-04-15 | 1983-10-15 | 1984-04-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-04-15 | 1987-10-15 | 1988-04-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-04-15 | 1991-10-15 | 1992-04-15 | $7700.00 | Window Closed / Lapsed |