In vitro aging of a heat/pressure-cured composite.

Specimens of a heat/pressure-cured microfill composite were aged in saline or distilled water at 37 degrees C up to 12 mon to determine if the flexure strength was affected by the aging media. No significant difference in the flexure strength was observed between the controls and the 12 mon aged specimens. Cyclic testing in distilled water resulted in a lower flexure strength at fracture than that observed for the aged specimens. This lower strength is attributed to fatigue of the silane bond, the resin matrix, and/or the filler particles.