Clinical evaluation of three amalgam alloys

A total of 117 high-copper amalgams of three types (platinum-modified, palladium-modified and dispersed phase) was placed by two operators in 59 patients. Restorations were assessed for marginal fracture, tarnish, corrosion, and tooth staining on continuous linear photographic rating scales. After one year, the platinum- and palladium-modified alloys showed a significant amount of tarnish, and all three alloys had statistically significant marginal fracture. The only significant difference between alloys at one year was the greater tarnish of the platinum-modified alloy. There was no association between static creep and marginal fracture.