Compressive Creep and Recovery of Composite Resins with Various Filler Contents in Water

Abstract

The compressive creep and the recovery of composites in water were examined. The creep strain of the composites after a 500h test linearly decreased with the increase of their filler content.Their water sorption during testing decreased with the increase of applied stress on the composites containing low filler contents. In the composites containing high filler contents, the water sorption was almost constant for some stress levels.The recovery of the composites after testing was significant immediately after testing. From the measurement of the water sorption of the composites, the microcrack or the craze should occur at the filler/matrix interface or in the matrix itself during the creep test, and water could diffuse to the microcrack or the craze after testing in unstressed conditions.This would explain the increase in the water absorbed in the composites in the recovery period.