Clinical performance of indirect composite onlays and overlays: 2-year follow up

This prospective clinical trial evaluated the clinical performance of indirect onlay and overlay restorations made of resin composite. From January 2012 to March 2013, a total of 60 patients (36 males, 24 females; mean age; 34.4 +/- 10 years) received 67 posterior onlay/overlay restorations in the maxilla or mandible made of laboratory-processed indirect composite (Gradia, GC, Japan). Patients were followed until March 2015. Two operators luted all restorations adhesively (Variolink II). Two independent calibrated examiners evaluated the restorations at baseline (2weeks), 6 months, and then annually, during regularly scheduled maintenance appointments, using the modified USPHS criteria for anatomic form, marginal adaptation, color match, surface roughness, marginal discoloration, secondary caries, and postoperative sensitivity. The observation periods involved 4 recalls during 24 months. Changes in the USPHS parameters were analyzed with the Friedman and Bonferroni-adjusted Wilcoxon signed-ranks tests (=.05). The mean observation period was 24.1 months. All restorations assessed were clinically acceptable with alfa scores predominating. Two restorations failed due to severe pain and subsequent extraction during the observation period. Not the color match (p>.05) but marginal adaptation (p<.05), marginal discoloration (p<.05), and surface roughness (p<.05) showed a significant difference between the baseline and the 2-year recall. No secondary caries or fractures were observed until the final follow-up. The indirect composite tested demonstrated to be successful for posterior onlay and overlays but deteriorations in qualitative parameters were observed during the 2-year clinical service.