The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 21, 1985
Filed:
May. 30, 1984
Arun Prasad, Cheshire, CT (US);
Jeneric Industries, Inc., Wallingford, CT (US);
Abstract
A dental alloy for porcelain-fused-to-metal restorations is provided which consists essentially of, on a weight basis, about 60-90% palladium, an effective amount of ruthenium up to about 2% for the purpose of grain-refining the alloy, an effective amount of copper up to about 30% for the purpose of lowering the melting point and raising the thermal expansion, up to about 15% indium, up to about 16% tin, up to about 12% zinc, up to about 5% gold, and from about 0.05 to about 0.25% boron or calcium boride, the total of said constituents being 100%, wherein the sum of the copper, indium, tin and zinc concentrations is greater than about 18%, the sum of the indium, tin and zinc concentrations is greater than about 10%, and the sum of the indium and zinc concentrations is greater than about 5%, such that said alloy exhibits a melting point between about 1100.degree. C. and 1400.degree. C. and a coefficient of thermal expansion of about 0.66 to 0.72 at 500.degree. C. To ensure essentially bubble-free restorations, the alloy is preferably made in a ceramic, rather than a carbon-containing, crucible and in a protective environment.