Comparative in vitro sliding-wear study of conventional, microfilled, and light-cured composite restoratives.

The sliding-wear behavior of a number of commercially available microfilled and light-cured composite restoratives has been investigated and compared with the wear characteristics of conventional composites. The surface profiles of the composite restoratives, both pre- and post-test, have also been examined in order to study material attrition processes. The results indicate that: (1) microfilled composites are significantly more resistant to sliding wear than are restoratives containing conventionally-sized filler particles; (2) light-cured, microfilled composites exhibit a lower rate of sliding wear than do self-curing, microfilled restoratives; and (3) the wear process leads to an increase in surface roughness for all materials tested, but microfilled materials display lower surface roughness values, both before and after sliding-wear tests, than do restoratives containing conventional-sized filler particles.