Clinical Effectiveness of Selective Etching in Class III Composite Restorations

Methods: In accordance with a paired-tooth study design, 38 patients received at least one pair of restorations. In each paired cavity, a mild two-step self-etch adhesive (Clearfil SE Bond, Kuraray) was used, either with or without enamel etching using phosphoric acid (C-SE etch and C-SE non-etch, respectively). Clearfil AP-X (Kuraray) was used as a restorative material. The restorations were evaluated at baseline, and after 6, 12, 24, 36 months for retention, marginal discoloration, marginal adaptation, postoperative sensitivity, and secondary caries using the modified Ryge criteria. The data were subjected to the statistical analysis (p=0.05).

Results: After 36-month follow-up, 80 of the 102 restorations were evaluated (78% recall rate). A retention rate of 100% was noted for both groups. C-SE non-etch restorations exhibited more small marginal defects (McNemar x², p=0.002) and superficial discolorations (McNemar x², p=0.001) than C-SE etch restorations at 36 months. There were no significant differences between both groups regarding postoperative sensitivity and secondary caries.

Conclusions: Although the clinical performance of the mild two-step self-etch adhesive in Class III cavities was acceptable after 36 months, selective etching of enamel margins improved the marginal quality of this adhesive by preventing small marginal defects and superficial discolorations.