2-Year Clinical Evaluation of Self-Etch Adhesives in Posterior Restorations

Objectives: To evaluate the 2-year clinical performance of 3 self-etch adhesives and one etch&rinse adhesive (control) in posterior composite restorations. Methods: Upon approval by an Institutional Review Board, 121 restorations were inserted in 38 subjects. The adhesives were applied as per manufacturers' instructions. Preparations were restored with a nanofilled composite resin (Filtek Supreme, 3M ESPE) and evaluated at baseline, 1 year, and 2 years. Statistical analyses included the McNemar and the Mann-Whitney non-parametric tests (P < 0.05). Results: At 2 years, 91 out of 121 restorations (recall level of 75.2 %) were evaluated using the USPHS modified criteria. The number of alfa ratings decreased significantly from baseline to 2 years for the 3 self-etch adhesives Adper Prompt L-Pop (AP), Clearfil S³ Bond (S3) and iBond (iB) in the categories color match, marginal staining, and marginal adaptation. iB resulted in 0% alfa ratings for marginal adaptation at 2 years. For One-Step Plus (OS), the etch&rinse control, only marginal staining was significantly worse at 2 years than at baseline. Post-operative sensitivity to air improved significantly for OS at 2 years, but this improvement was already detected at 1 year. When the 2-year evaluation criteria were pooled by pairs of adhesives, OS resulted in a significantly greater number of alfa ratings for marginal adaptation than the other three adhesives. On the other hand, iB resulted in significantly lower number of alfa ratings than any of the other 3 adhesives for color match and marginal staining. AP, S3, and OS resulted in statistically similar number of alfa ratings for marginal staining and color match. There were no significant differences in any of the evaluation criteria between AP and S3. Conclusion: Only OS, the etch&rinse adhesive, resulted in good marginal adaptation at 2 years. One of the self-etch adhesives, iB, resulted in unacceptable clinical performance.