A clinical comparison of resin composite inlay and onlay posterior restorations and cast-gold restorations at 7 years.
OBJECTIVE: The purpose of this study was to evaluate the clinical performance of Concept indirect posterior heat- and pressure-polymerized restorative material and compare it to the performance of cast gold. METHOD AND MATERIALS: Inlays and onlays placed in a standardized manner as part of a clinical study were evaluated at 7 years. Eighteen patients (45%) who had received 36 Concept restorations returned and were evaluated using the US Public Health Service criteria. Restorations were evaluated in seven categories as the percentage receiving Alfa (ideal), Bravo (clinically acceptable), or Charlie (clinically unacceptable) scores or as restoration no longer present. Fourteen of the restorations were cemented with Heliobond bonding resin and 13 were cemented with Special Bond bonding resin. Each patient also received a cast-gold restoration for comparison. RESULTS: Concept restorations received scores of Alfa at the following rates: color match, 64%; interfacial staining, 47%; secondary caries, 75%; wear, 58%; marginal integrity, 64%; surface texture, 72%; and axial contour, 58% (in 14% this category was not applicable because they were Class I restorations). Nine Concept restorations (25%) were no longer present. Fifteen of 18 gold restorations were present at this recall. Statistical analysis indicated no significant differences in any categories between the two bonding resins used with Concept restorative material and the gold restorations. CONCLUSION: At 7 years in vivo, the Concept indirect posterior restorative system yields clinically acceptable restorations, particularly in premolars.