Degussa Aktiengesellschaft

Gernot Schoeck

Werner Groll

Bernd Kempf

Doris Hathaway

Hans-Martin Ringelstein

Manfred Stuemke

Bernd Meier

Gold-palladium alloys with a high gold content for dental applications should, for reasons of biocompatibility, not contain any toxically dubious components. For particularly corrosion-resistant and biocompatible Type 4 alloys, tin is needed as the only base-metal component in amounts between 0.7 and 5.8 wt % if one remains within defined limits in a palladium-tin diagram of FIG. 1, for Pt values less than 2%. Such alloys contain, in addition to gold and tin, 6 to 25 wt % palladium, 0 to 12 wt % platinum and 0 to 2 wt % of at least one of iridium, rhodium and/or ruthenium.

Gold-palladium alloys for dental materials

Gold-free palladium-silver alloys for dentures [dental prostheses] which alloys can be veneered without color changes with dental ceramics and can be easily removed from the mold after the casting contain 45 to 80% by weight palladium, 7 to 50% by weight silver, 0 to 5% by weight gold, 0 to 5% by weight tin, 0 to 5% by weight indium, 0 to 3% by weight zinc, 0 to 2% by weight copper, 0 to 1% by weight ruthenium, iridium and/or rhenium, 0 to 7% by weight gallium, 0 to 5% by weight cobalt and 0 to 3% by weight germanium, whereby of the elements gallium, cobalt and germanium at least two must be present with contents totalling 2 to 9% by weight.

Use of palladium-silver alloys for the manufacture of dentures

A yellow dental alloy is disclosed with high gold content for castings and ceramic veneers with an adjusted thermal expansion coefficient that does not produce any undesirable discoloration of the ceramic veneers and that is very hard. It contains 70 to 85% by weight gold, 5 to 13% by weight silver, 2 to 9% by weight platinum, 0 to 4.5% by weight palladium, 0.05 to 1% by weight iridium, rhenium, rhodium and/or ruthenium, 2 to 8% by weight copper, 0.1 to 6% by weight indium, zinc and/or germanium, and 0 to 4% by weight gallium, iron and/or tungsten.

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Bruchkoebel, Germany

Gernot Schoeck