Reciprocating wear test of dental composites: effect on the antagonist

Resin composites were first introduced as anterior restorative materials, but are more and more used in posterior teeth, as amalgam replacements. Nowadays the so-called ‘condensable’ composites are frequently used in posterior teeth. These materials are subjected to high values of contact and mastigatory loads, loading rates and sliding distances. In such contact conditions, wear is the major failure mode of dental composites. Wear of dental composites includes such diverse phenomena as adhesion, abrasion and fatigue. These mechanisms may operate either alone or in combination. Most of the performed studies involve commercial composite materials and focus on the effect of curing time, and their reflection on the abrasive wear behavior. The wear compatibility of both materials in contact should be one of the concerns of the wear studies. However, the majority of studies do not consider the wear produced on the antagonist material. The present study aims to the understanding of the behavior of commercial composites under reciprocating contact. For the tests, a glass ball was used as opponent. At the end of each test, the wear volume was calculated on both contact materials: the composite and the glass counterface. The removal mechanisms involved in the wear process were discussed taking into account SEM observations of the contact surfaces.