The effect of gamma 1 and gamma 2 on the creep deformation of dental amalgams has been investigated. It has been shown that the creep of a conventional amalgam is not dependent on gamma 1 as was previously reported. Rather it is strongly influenced by gamma 2 and its volume fraction. It has been speculated that Sn-rich grain boundaries also enhance creep by facilitating grain boundary sliding. The reported correlation between creep and marginal fracture has been explained in terms of this dependence of creep on corrosion-prone Sn-rich microstructural constituents of amalgams.