Self-etch or etch-and-rinse mode did not affect the microshear bond strength of a universal adhesive to primary dentin.

This study evaluated the microshear bond strength (µSBS) of resin composite to primary dentin using a universal adhesive in etchand-rinse mode or self-etch mode. Flat ground dentin surfaces were created on forty extracted human primary incisors and randomly assigned into four groups (n=10): Adper Single Bond II (ASB), Clearfil SE Bond (CSE), Single Bond Universal etch-and-rinse (SBUER) and Single Bond Universal self-etch (SBU-SE). Adhesive was applied on the dentin surface, which was subsequently bonded with a resin composite. The µSBS test was performed using a universal testing machine at a crosshead speed of 1 mm/min. The ASB group generated a lower mean µSBS (19.1±3.4 MPa) than those of the other groups [SBU-ER (24.3±2.7 MPa), SBU-SE (25.1±2.4 MPa), and CSE (25.3±2.7 MPa)]. Adhesive failure was the most common failure mode in each group. In conclusion, SBU used in etch-and-rinse or self-etch mode resulted in similar bond strength to primary dentin.