1. Ceramic brackets;Swartz;J Clin Orthod,1988
2. Occlusal wear in prosthodontics;Mahalick;J Am Dent Assoc,1971
3. Studies on the wear of porcelain, enamel, and gold;Monasky;J Prosthet Dent,1971
4. Friction and wear restorative dental materials;Tillitsen;J Dent Res,1971