Two independent evaluations of ten amalgam alloys

Two independent research groups evaluated marginal failure and conducted creep tests on 10 commercial amalgam alloys. Correlation data determined that both laboratory tests and clinical results were essentially the same between the two studies. The 2-year clinical results indicate that five alloys, Cupralloy, Dispersalloy, Indiloy, Phasealloy, and Tytin give best results. Creep correlated with the rate of marginal failure within a study when all alloys were assessed; however, for the seven gamma-2-free alloys, there was no significant relationship between in vivo and in vitro data. Since creep tests did not predict marginal failure of the gamma-2-free alloys, the results of clinical studies should be the guide to selection of the better amalgam alloys.