Use
Amalgams are predominantly alloys of silverand mercury, but they may contain minoramounts of tin, copper, and zinc for hardeningpurposes, for example, 33% silver, 52% mercury,12% tin, 2% copper, and less than 1%zinc. Liquid mercury is added to a powder of aprecursor alloy of the other metals. After compaction,the mercury diffuses into the silverbasemetal to give a completely solid alloy.Gold-base dental alloys are preferred over puregold because gold is relatively soft. The mostcommon dental gold alloy contains gold (80 to90%), silver (3 to 12%), and copper (2 to 4%).For higher strengths and hardnesses, palladium and platinum (up to 3%) are added, and thecopper and silver are increased so that the goldcontent drops to 60 to 70%. Vitallium, an alloyof cobalt (65%), chromium (5%), molybdenum(3%), and nickel (3%), and other corrosionresistantalloys are used for bridgework andspecial applications.