This randomized clinical trial evaluated the efficacy of five different adhesive systems in the restoration of occlusal cavities after one year of function. Two etch-and-rinse (Optibond™FL, Prime&Bond®NT™) and three self-etch (Clearfil™SE Bond, Xeno®III, Xeno®V+) adhesive systems were evaluated on 159 occlusal restorations, incrementally filled with a microhybrid composite resin. Restorations were assessed using the FDI criteria at baseline, 6 months and 1 year. Statistical analysis was performed with Friedman-test and Kruskal-Wallis test (p<0.05). At 1 year, 153 restorations were evaluated. A statistically significant decrease in the number of restorations with marginal adaptation classified as excellent occurred for the self-etch adhesives (p<0.01). Etch-and-rinse adhesives presented better performance than any of the self-etch systems (p<0.01) in terms of marginal adaptation. All cases were considered no less than satisfactory. Marginal adaptation was the most influent parameter on the distinctive performance of the adhesives where etch-and-rinse systems performed significantly better than self-etch systems.
Keywords: Adhesives; Composite resin; Posterior teeth; Randomized clinical trial.