Four u.v.-polymerized composites (Estilux, Nuva-Fil, Nuva-Fil P.A. and Uvio-Fil) were clinically evaluated in Class I and II cavity preparations in permanent teeth. The restorations were evaluated at baseline, 1, 2, 3, 4 and 5 years using USPHS criteria for direct evaluation and at 3, 4 and 5 years using the Leinfelder method for indirect evaluation of wear. The wear measured by the USPHS method showed increasing wear rates in earlier reports, apparently due to the limited sensitivity of the scale to early wear. The wear by the Leinfelder method showed gradually decreasing wear rates. There were no statistically significant differences among the wear values for the four u.v.-cured materials or between these materials and the self-cured and visible light-cured controls.