US4370165A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Low silver dental amalgam alloy composition
Assignee: Dentsply Research and Development Corp
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Filing: 1981-05-21
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Granted: 1983-01-25
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Expires: 2001-05-21
Abstract
Abstract A composition adapted for amalgamation with mercury to form a dental amalgam, which consists essentially of a uniform mixture of: (a) A first alloy composed of at least 65 weight percent silver, up to 29 weight percent tin, up to 6 weight percent copper, and up to 2 weight percent zinc; and (b) A second alloy composed of from 46 to 51 weight percent silver, from 4 to 6 weight percent tin, and from 45 to 48 weight percent copper.
Inventors
- 👤 Robert De Luca
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 14:01
CPC Classifications
C; C22; C22C; C22C5/00; C22C5/06; C22C5/08; A; A61; A61K; A61K6/00; A61K6/80; A61K6/84; A61K6/847
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
185 words
A composition adapted for amalgamation with mercury to form a dental amalgam, which consists esentially of a uniform mixture of: (a) A first alloy composed of at least 65 weight percent silver, up to 29 weight percent tin, up to 6 weight percent copper, and up to 2 weight percent zinc; and (b) A second alloy composed of from 46 to 51 weight percent silver, from 4 to 6 weight percent tin, and from 45 to 48 weight percent copper, wherein, when said composition is mixed with from 40 to 60 weight percent memory, based on weight of said composition plus mercury, the resulting dental amalgam has the following properties: 1-hour compressive strength, at least 16,000 psi; 24 hour compressive strength, at least 50,000 psi; percent flow, less than 1; dimensional change, less than ±15 microns/centimeter; creep, less than 0.5 percent; and working time, from 2 to 6 minutes, the said components (a) and (b) being present in proportions of from 33 to 67 weight percent (a) and from 67 to 33 weight percent (b), the percentage being based on weight of (a) plus (b).
Claim 2
Dependent Claim
185 words
A composition adapted for amalgamation with mercury to form a dental amalgam, which consists esentially of a uniform mixture of: (a) A first alloy composed of at least 65 weight percent silver, up to 29 weight percent tin, up to 6 weight percent copper, and up to 2 weight percent zinc; and (b) A second alloy composed of from 46 to 51 weight percent silver, from 4 to 6 weight percent tin, and from 45 to 48 weight percent copper, wherein, when said composition is mixed with from 40 to 60 weight percent memory, based on weight of said composition plus mercury, the resulting dental amalgam has the following properties: 1-hour compressive strength, at least 16,000 psi; 24 hour compressive strength, at least 50,000 psi; percent flow, less than 1; dimensional change, less than ±15 microns/centimeter; creep, less than 0.5 percent; and working time, from 2 to 6 minutes, the said components (a) and (b) being present in proportions of from 33 to 67 weight percent (a) and from 67 to 33 weight percent (b), the percentage being based on weight of (a) plus (b).
Claim 3
Dependent Claim
19 words
The composition of claim 1 wherein the components (a) and (b) are employed in approximately equal proportions, by weight.
Claim 4
Dependent Claim
13 words
A dental amalgam produced by mixing the composition of claim 1 with mercury.
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) | 1986-01-24 | 1986-07-26 | 1987-01-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-01-24 | 1990-07-26 | 1991-01-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-01-24 | 1994-07-26 | 1995-01-25 | $7700.00 | Window Closed / Lapsed |