In vitro deformation failure analysis of dental amalgams.

The in vitro deformation failure behavior of the conventional and the recent high copper dental amalgams is studied under different strain rates. The conventional silver-tin amalgams exhibited significant slow compressive flow at low strain rates, but failed catastrophically at the higher loading rates. On the other hand, amalgams containing highest copper contents showed no compressive flow and failed catastrophically at all the loading rates. The slow compressive flow in the conventional dental amalgams indicate that dislocations may play an important role in the deformation process of the amalgams at the lower strain rates.