Abstract: Objective：To compare the clinical effectiveness of the two-step etch-and-rinse with the one-step self-etch adhesive in non-carious cervical lesions. Methods: Fifty patients were selected, each with at least two wedge-shaped defects in the mouth. The paired defects were randomly bonded either with the two-step etch-and-rinse adhesive α or the one-step self-etch adhesive β and then restored with resin composite. The treatment was carried out by one practitioner according to standard procedures. The evaluation was performed by another practitioner according to modified United States Public Health Service (USPHS) criteria at one week, six months and eighteen months after treatment. Chi-square test was used for statistical analysis. Results: Fifty restorations were placed for each group. Forty-eight patients attended the six months recall, with two restorations loss for each group. Forty-four patients attended the eighteen months recall, with accumulative four restorations loss for adhesive α and six restorations loss for adhesive β. The retention rate was 90.0% for group α and 86.4% for group β. Marginal adaptation of three restorations in group α and five restorations in group β were scored Bravo; while for marginal discoloration, two restorations in group α and three restorations in group β were scored Bravo respectively. No secondary caries and post-operative sensitivity occurred for any of the restorations after eighteen months. No significant difference was detected between the groups for any evaluation criteria (P>0.05). Conclusion: Within the observation period of this study, the two-step etch-and-rinse adhesive and the one-step self-etch adhesive showed similar clinical performance. The long term follow-up is still warranted.

Key words: Dentin-bonding agents, Acidetching, dental, Composite resins, Dental bonding