The deformation behavior of 8 different posterior composites under uniaxial static and dynamic compression have been investigated. The influence of water sorption on the mechanical properties was also assessed. The static creep behavior during a 2 h period and the creep recovery for the following 2 h were determined. Stress/strain curves were recorded during cyclic loading at a frequency of 0.25 Hz for 2 h. Water sorption increased the creep and decreased the creep recovery. Both static and dynamic creep values were higher for the microfilled materials than for the other types of composite materials.

Reference
Creep and recovery of composites for use in posterior teeth during static and dynamic compression
A.Odén, I.E.Ruyter, H.Øysæd
Dental Materials Volume 4, Issue 3, June 1988, Pages 147-150