US4702765A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making selenium-containing amalgam alloys for dental restoration
Assignee: GC Corp
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Filing: 1986-02-18
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Granted: 1987-10-27
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Expires: 2006-02-18
Abstract
Abstract Selenium-containing amalgam alloys for dental restoration comprises 0.1-50% by weight of any one of the following alloy powders (A), (B) and (C) mixed with 50-99.9% by weight of the following amalgam alloy powders (D). (A): Silver alloy powders containing no less than 50% by weight of silver and 0.01-10% by weight of selenium, (B): Copper alloy powders containing no less than 50% by weight of copper and 0.01-5% by weight of selenium, (C): Alloy powders mix of (A) with (B) wherein the total amount of silver and copper is adjusted to no less than 50% by weight, and the amount of selenium to 0.01-10% by weight, and (D): Silver-tin-copper amalgam alloy powders. At least one of the any one of (A), (B) and (C) and (D) may be pre-amalgamated with mercury in an amount of no higher than 3% by weight based on the total weight thereof.
Inventors
- 👤 Atsushige Sato
- 👤 Ishi Miura
- 👤 Yasuhiro Kumei
- 👤 Osamu Okuno
- 👤 Tsuyoshi Nakano
- 👤 Bunsaku Yoshida
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 09:09
CPC Classifications
C; C22; C22C; C22C7/00; A; A61; A61K; A61K6/00; A61K6/80; A61K6/84; A61K6/847; Y; Y10; Y10S; Y10S75/00; Y10S75/955
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
106 words
A process for the preparation of selenium-containing amalgam alloys for dental restoration comprising the steps of: melting a copper alloy containing no less than 50% by weight of copper and 0.01-5% by weight of selenium, reducing the resulting melt to powders having a desired particle size by spraying the melt by means of a centrifugal force, and mechanically mixing 0.1-50% by weight of the thus obtained powders with 50-99.9% by weight of a silver-tin-copper amalgam alloy powder obtained by melting a silver-tin-copper amalgam alloy, and reducing the resulting melt to a powder having a desired particle size by spraying the melt in an inert gas stream.
Claim 2
Dependent Claim
106 words
A process for the preparation of selenium-containing amalgam alloys for dental restoration comprising the steps of: melting a copper alloy containing no less than 50% by weight of copper and 0.01-5% by weight of selenium, reducing the resulting melt to powders having a desired particle size by spraying the melt by means of a centrifugal force, and mechanically mixing 0.1-50% by weight of the thus obtained powders with 50-99.9% by weight of a silver-tin-copper amalgam alloy powder obtained by melting a silver-tin-copper amalgam alloy, and reducing the resulting melt to a powder having a desired particle size by spraying the melt in an inert gas stream.
Claim 3
Dependent Claim
110 words
A process for the preparation of selenium-containing amalgam alloys for dental restoration comprising the steps of: melting a copper alloy containing no less than 50% by weight of copper and 0.01-5% by weight of selenium, reducing the resulting melt to powders having a desired particle size by spraying the melt in an inert gas stream by means of a nozzle, and mechanically mixing 0.1-50% by weight of the thus obtained powders with 50-99.9% by weight of a silver-tin-copper amalgam alloy powder obtained by melting a silver-tin-copper amalgam alloy, and reducing the resulting melt to a powder having a desired particle size by spraying the melt in an inert gas stream.
Claim 4
Dependent Claim
110 words
A process for the preparation of selenium-containing amalgam alloys for dental restoration comprising the steps of: melting a copper alloy containing no less than 50% by weight of copper and 0.01-5% by weight of selenium, reducing the resulting melt to powders having a desired particle size by spraying the melt in an inert gas stream by means of a nozzle, and mechanically mixing 0.1-50% by weight of the thus obtained powders with 50-99.9% by weight of a silver-tin-copper amalgam alloy powder obtained by melting a silver-tin-copper amalgam alloy, and reducing the resulting melt to a powder having a desired particle size by spraying the melt in an inert gas stream.
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) | 1990-10-26 | 1991-04-27 | 1991-10-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-10-26 | 1995-04-27 | 1995-10-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-10-26 | 1999-04-27 | 1999-10-27 | $7700.00 | Window Closed / Lapsed |