Clinical evaluation of high-copper amalgams.

PURPOSE

To compare the clinical performance of two high-copper amalgam alloys with different compositions by evaluating marginal fracture of each restoration over a 2-year period.

MATERIALS AND METHODS

Restorations of Valiant PhD and Zenith Premium alloy were placed in Class I and II cavity preparations in patients and evaluated at baseline, 1 and 2 years to determine their degree of marginal breakdown.

RESULTS

After 2 years, the Zenith Premium alloy exhibited significantly less marginal breakdown than the Valiant PhD alloy with no significant additional deterioration of the Zenith restorations between the 1st and 2nd year. The data indicate that the Zenith Premium alloy exhibits less marginal deterioration than Valiant PhD so it may be predicted that it will perform better long term. A possible explanation for this better performance may be that the Zenith Premium contains zinc while the Valiant PhD includes palladium but no zinc in its formulation.