Stress/strain behavior of dental amalgams.

The stress/strain behavior at different strain rates and the creep rate of dental amalgams were evaluated and compared to the microstructure. The results indicate that substantial differences exist both in strength and strain at fracture. The strain at fracture for high strain rates was associated with the nature of the particle-matrix interface, in that amalgams with an interpenetrating interface exhibited some ductility, while amalgams with an abrupt interface exhibited practically no plastic deformation at fracture. The correlation between creep and slow compressive strength was verified and it was suggested that grain boundary sliding was the deformation mechanism in both cases.