In vitro Wear of Aged Composite

Wear of restorative materials has been characterized in vitro using single-pass sliding.'4 Wear patterns and surface structures of composite restorations in vivo have been reported by Kusy and Leinfelder5 and by O'Brien and Yee.6 However, there have been few reports on the correlation between in vitro and in vivo wear. One reason could be that the in vivo wear characteristics result from gradual changes in the properties of the composite restorative materials in the oral environment. Accelerated aging of composites in vitro has been shown to cause erosion accompanied by changes in surface profiles and exposure of filler particles.7 The present study characterizes the in vitro wear of composite restorative materials by single-pass sliding after accelerated aging and compares the wear characteristics with those of unaged composite restorative materials.