Purpose: To evaluate the wear resistance of resin restorations (Z100; Tetric; Charisma) in posterior teeth (Class I and II) after 6 years.
Material and methods: One operator placed 103 restorations in 13 patients. Each patient had at least three restorations with three different resin-based composites. All restorations were made using rubber dam isolation and the cavity design was restricted to the elimination of carious tissue. Deeper cavities were covered with calcium hydroxide and/or glass ionomer cement and in shallow and medium cavities only an adhesive system was used. Each composite was placed according to the manufacturer's instructions. In Class II cavities the resin placement followed the Krejci et al or Opdam et al technique, according to the cavity size. One week later, the restorations were finished/polished and stone dies were immediately built from the impressions. Eleven patients attended the 6-year recall, and 90 restorations were evaluated based on new stone dies. The 6-year stone dies were compared with the baseline ones by two examiners. The evaluation was based on the modified Mahler et al. criteria and Busato et al, using six different scores. The scores were statistically analyzed.
Results: A total of 87% of the restorations were analyzed after 6 years. Only 15% (6 for Tetric and 7 for Charisma) of the 90 evaluated restorations had been already replaced. No statistical difference was found in the wear rate of the composites used in this study. None of the patients complained of any symptom after the placement of the composite (baseline data) nor after 6 years.