Eighteen-month randomized clinical trial on the performance of two etch-and-rinse adhesives in non-carious cervical lesions

Purpose: An 18-month randomized, controlled prospective study evaluated, in an intra-individual comparison, the clinical performance of two-step etch-and-rinse adhesives in non-carious cervical lesions (NCCL). Methods: 35 subjects, with at least two similar sized NCCL participated in this study. After sample size calculation, 70 restorations were placed, according to one of the following groups: Adper Single Bond 2 (SB) and Ambar (AM). The restorations were placed incrementally using a resin composite (Opallis). The restorations were evaluated at baseline and after 6 and 18 months according to the FDI criteria. The differences in the ratings of the two materials after 6 and 18 months were tested with Fisher's exact test (alpha = 0.05), and the performance of the each material at baseline and after 6 and 18 months was evaluated by Wilcoxon test (alpha = 0.05). Results: All subjects attended the 18-month recall. No significant differences were observed between the materials for any criteria evaluated. Only four restorations (two from each material) were lost after 18 months. Thus, the retention rates of both materials at 18 months were 94.2% (95% CI 81-98%). Nine restorations (four Ambar and five Adper Single Bond 2) showed marginal discoloration which was solved with a polishing procedure. Both adhesive systems showed acceptable clinical retention rates after 18 months.