Eighteen-month clinical performance of preheated nanoceramic resin-based composites in Class I occlusal cavities: A randomized clinical trial

AIMS: This study aimed to evaluate the effect of preheated nanoceramic resin-based composite (RBC) (Ceram-X-Mono) placed in Class I occlusal cavities over a period of 18 months. SETTINGS AND DESIGN: This study involves split-mouth design, randomized controlled clinical trial (RCT) MATERIALS AND METHODS: One operator restored 60 Class I occlusal cavities in 24 patients. Preheating of nanoceramic RBC to 60°C for 10 min was performed before insertion of the material into 30 prepared cavities, whereas 30 restorations in the nonpreheated group were placed according to the manufacturer's instructions. Two observers evaluated the restorations using Federation Dentaire Internationale (FDI) criteria at baseline, 6, 12, and 18 months. STATISTICAL ANALYSIS: Kappa index, Friedman and Wilcoxon matched pair test, and Krushal-Wallis and Mann-Whitney tests were used for statistical analysis. RESULTS: 100% retention rates were seen in both the groups. In nonpreheated group, significant difference was observed for surface staining (P = 0.0001), color stability (P = 0.0277), anatomic form (P = 0.0431), and marginal adaptation (P = 0.0051), whereas in preheated group, significant increase in surface staining (P = 0.0051) was recorded. There was a statistically significant difference observed between the preheated and nonpreheated groups at different time periods for the tested clinical parameters. CONCLUSION: Within the limitations of this RCT of 18 months, preheated nanoceramic RBC restorations showed better clinical performance compared to nonpreheated group.