Marginal microleakage of class V resin-based composite restorations bonded with six one-step self-etch systems

This study compared the microleakage of class V restorations bonded with various one-step self-etching adhesives. Seventy class V resin-based composite restorations were prepared on the buccal and lingual surfaces of 35 premolars, by using: Clearfil S3 Bond, G-Bond, iBond, One Coat 7.0, OptiBond All-In-One, or Xeno IV. The Adper Single Bond etch-and-rinse two-step adhesive was employed as a control. Specimens were thermocycled for 500 cycles in separate water baths at 5°C and 55°C and loaded under 40 to 70 N for 50,000 cycles. Marginal microleakage was measured based on the penetration of a tracer agent. Although the control showed no microleakage at the enamel margins, there were no differences between groups (p = 0.06). None of the adhesives avoided microleakage at the dentin margins, and they displayed similar performances (p = 0.76). When both margins were compared, iBond® presented higher microleakage (p < 0.05) at the enamel margins (median, 1.00; Q3-Q1, 1.25-0.00) compared to the dentin margins (median, 0.00; Q3-Q1, 0.25-0.00). The study adhesives showed similar abilities to seal the margins of class V restorations, except for iBond®, which presented lower performance at the enamel margin.