Pages 425-430, Language: EnglishMatsumura / LeinfelderThe in vitro wear resistance of foru types of light-activated composite resins designed for crown and bridge veneers was determined by means of a three-body wear-testing device. After repeated cycles of loading, the wear values were measured with a profilometer, and surface textures were observed through a scanning electron microcscope. All of the composite resin veneering materials examined in this investigation exhibited greater wear resistance than an unfilled poly(methyl methacrylate)-based material. The worn surface of veneering materials demonstrated outlines of fillers, indicating the difference in wear resistance between the resin matrix and the filler.