US4210447A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dental restorations using castings of non-precious metals
Assignee: 3M Co
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Filing: 1978-11-20
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Granted: 1980-07-01
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Expires: 1998-11-20
Abstract
Abstract A method and material for making dental restorations by using a porcelain-covered body of a non-precious metal alloy. The alloy preferably includes about 58-68% nickel, 18-23% chromium, 6-10% molybdenum, up to 5% of at least one rare-earth element, up to 4% columbium plus tantalum, up to 2% iron, and lesser quantities of carbon, aluminum, titanium, silicon and manganese. The alloy is resistant to corrosion by mouth fluids, is easy to finish and polish, and is closely matched to the thermal-expansion properties of commercially available dental porcelains. The alloy does not contaminate alloy-melting crucibles, exhibits excellent bonding characteristics to dental porcelains, is easy to melt and cast, and has sufficient ductility to enable margin burnishing of dental-restoration castings of the alloy.
Inventors
- 👤 Min H. Tsai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 11:19
CPC Classifications
C; C22; C22C; C22C19/00; C22C19/03; C22C19/05; C22C19/051; C22C19/055; A; A61; A61K; A61K6/00; A61K6/80; A61K6/84; A61K6/842
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
71 words
A non-precious metal base for a dental restoration, comprising: a body of a stainless metal alloy configured for intra-oral installation, the alloy comprising about: 58 to 68 percent nickel, 18 to 23 percent chromium, 6 to 10 percent molybdenum, 1 to 4 percent columbium plus tantalum, and 0.01 to 5 percent of at least one rare-earth element selected from the group consisting of lanthanum, cerium, praseodymium, neodymium, samarium, gadolinium, and dysprosium.
Claim 2
Dependent Claim
71 words
A non-precious metal base for a dental restoration, comprising: a body of a stainless metal alloy configured for intra-oral installation, the alloy comprising about: 58 to 68 percent nickel, 18 to 23 percent chromium, 6 to 10 percent molybdenum, 1 to 4 percent columbium plus tantalum, and 0.01 to 5 percent of at least one rare-earth element selected from the group consisting of lanthanum, cerium, praseodymium, neodymium, samarium, gadolinium, and dysprosium.
Claim 3
Dependent Claim
103 words
A dental restoration, comprising: a body of stainless metal alloy configured for intra-oral installation, and a porcelain jacket fired on the alloy body, the alloy comprising: nickel, 58 to 68 percent; chromium, 18 to 23 percent; molybdenum, 6 to 10 percent; columbium plus tantalum, 1 to 4 percent; iron, 0.02 to 2 percent; silicon, 0.01 to 0.5 percent; manganese, 0.01 to 0.4 percent; titanium, 0.01 to 0.2 percent; aluminum, 0.01 to 1.0 percent; carbon, 0.01 to 0.1 percent; and 0.01 to 5 percent of at least one rare-earth element selected from the group consisting of lanthanum, cerium, praseodymium, neodymium, samarium, gadolinium, and desprosium.
Claim 4
Dependent Claim
103 words
A dental restoration, comprising: a body of stainless metal alloy configured for intra-oral installation, and a porcelain jacket fired on the alloy body, the alloy comprising: nickel, 58 to 68 percent; chromium, 18 to 23 percent; molybdenum, 6 to 10 percent; columbium plus tantalum, 1 to 4 percent; iron, 0.02 to 2 percent; silicon, 0.01 to 0.5 percent; manganese, 0.01 to 0.4 percent; titanium, 0.01 to 0.2 percent; aluminum, 0.01 to 1.0 percent; carbon, 0.01 to 0.1 percent; and 0.01 to 5 percent of at least one rare-earth element selected from the group consisting of lanthanum, cerium, praseodymium, neodymium, samarium, gadolinium, and desprosium.
Claim 5
Independent Claim
99 words
A method for making a dental restoration, comprising: firing a porcelain jacket on a body of non-precious metal alloy, the alloy comprising: nickel, 58 to 68 percent; chromium, 18 to 23 percent; molybdenum, 6 to 10 percent; columbium plus tantalum, 1 to 4 percent; iron, 0.02 to 2 percent; silicon, 0.01 to 0.5 percent; manganese, 0.01 to 0.4 percent; titanium, 0.01 to 0.2 percent; aluminum, 0.01 to 1.0 percent; carbon, 0.01 to 0.1 percent; and 0.01 to 5 percent of at least one rare-earth element selected from the group consisting of lanthanum, cerium, praseodymium, neodymium, samarium, gadolinium, and dysprosium.
Claim 6
Independent Claim
99 words
A method for making a dental restoration, comprising: firing a porcelain jacket on a body of non-precious metal alloy, the alloy comprising: nickel, 58 to 68 percent; chromium, 18 to 23 percent; molybdenum, 6 to 10 percent; columbium plus tantalum, 1 to 4 percent; iron, 0.02 to 2 percent; silicon, 0.01 to 0.5 percent; manganese, 0.01 to 0.4 percent; titanium, 0.01 to 0.2 percent; aluminum, 0.01 to 1.0 percent; carbon, 0.01 to 0.1 percent; and 0.01 to 5 percent of at least one rare-earth element selected from the group consisting of lanthanum, cerium, praseodymium, neodymium, samarium, gadolinium, and dysprosium.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-07-01 | 1983-12-31 | 1984-07-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-07-01 | 1987-12-31 | 1988-07-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-07-01 | 1991-12-31 | 1992-07-01 | $7700.00 | Window Closed / Lapsed |