Randomized clinical trial of four adhesion strategies: 18-month results

Statement of the Problem: With Institutional Review Board approval, 39 patients who needed restoration of noncarious cervical lesions (NCCLs) were enrolled in this study. A total of 125 NCCLs were selected and randomly assigned to four groups: 1) a three-step etch-andrinse adhesive, Adper Scotchbond Multi-Purpose (MP, 3M ESPE, St Paul, MN, USA); 2) a two-step etch-and-rinse adhesive, Adper Single Bond Plus (SB, 3M ESPE); 3) a two-step selfetch adhesive, Adper Scotchbond SE (SE, 3M ESPE); and 4) a one-step self-etch adhesive, Adper Easy Bond (EB, 3M ESPE). A nanofilled composite resin was used for all restorations. Restorations were evaluated at six months and 18 months using modified U.S. Public Health Service (USPHS) parameters. Results: At six months after initial placement, 107 restorations (85.6% recall rate) were evaluated. At 18 months, 94 restorations (75.2% recall rate) were available for evaluation. The 6 mo/18 mo overall retention rates (%) were 100/90.9 for MP; 100/91.7 for SB; 100/90.9 for SE; and 96.4/92.3 for EB with no statistical difference between any pair of groups at each recall. Sensitivity to air decreased significantly for all adhesives from the preoperative to the postoperative stage and was stable thereafter. Interfacial staining did not change statistically from baseline to six months; however, interfacial staining at the enamel margins was statistically worse at 18 months than at baseline for the two self-etch adhesives EB and SE. Marginal adaptation was statistically worse at 18 months compared with baseline only for EB. This tendency was already significant at the six-month recall. Conclusion: Although 18-month retention was similar for the different adhesion strategies, enamel marginal deficiencies were more prevalent for the self-etch adhesives.