Abstract: Dental restorations are made of a high palladium alloy which consists essentially of, on a weight basis, 70-82 percent palladium; 5-8 percent gold; 6.5-8 weight percent silver; 5-9 percent gallium; from 4 to 8 weight percent of a surface oxide producing modifier selected from the group consisting of indium, tin and mixtures thereof, from 0.01 up to 2 percent, ordinarily less than about 0.5 percent, of an oxygen scavenging component which is a member selected from the group consisting of germanium, lithium and mixtures thereof; and up to 2 percent of a grain refiner selected from the group consisting of ruthenium, rhenium and iridium. Alloy can be melted without the need of shielding the alloy from the atmosphere.
Type:
Grant
Filed:
January 25, 1989
Date of Patent:
July 24, 1990
Assignee:
Williams Dental Company, Inc.
Inventors:
Clyde E. Ingersoll, Stephen P. Schaffer, Patrick J. McCabe
Abstract: A yellow dental alloy containing a colored intermetallic compound of palladium and indium as 15-85% by weight of the alloy and at least 10% by weight of silver and as desired gold 0-30%, copper 0-45% and silver 10-50%. This alloy exhibits a pale yellow gold color which it derives from the interaction of two white colored metals--palladium and indium. Various alloying additions are specified to improve castability, ductility, strength, hardness, tarnish and corrosion resistance.
Type:
Grant
Filed:
April 22, 1987
Date of Patent:
February 14, 1989
Assignee:
Williams Dental Company, Inc.
Inventors:
Stephen P. Schaffer, Clyde E. Ingersoll