A 5-year study comparing a posterior composite resin and an amalgam.

Eighty class I and class II light-cured posterior composite resin restorations were compared with 43 class I and class II amalgam restorations during a 5-year period after placement. The results of this clinical study showed that both materials were satisfactory during the time period and that the only significant statistical differences are a poorer marginal integrity for the amalgam and a greater wear rate for the composite resin.