The effect of double-coating and times on the immediate and 6-month dentin bonding of universal adhesives.

Objective: The purpose of this study was to evaluate the effect of double-application coats and times on microtensile bond strength (μTBS) and adhesive-dentin interfaces created by dentin adhesive systems after 6 months of storage in water.

Materials And Methods: Two-hundred sixteen extracted non-carious human third molars were selected for the study. Single-Bond Universal (SU) and All-Bond Universal (AU), Adper Easy One (Eo) Self-Etch adhesive and Adper Single-Bond 2 (Sb) etch-and-rinse adhesive were applied to a flat dentin surface using three methods (1): dentin adhesives were applied as recommended by the manufacturers; (2): two consecutive coats of dentin adhesives were applied before photo-polymerization; and (3): a single coat of adhesive was applied but with twice the manufacturers recommended application time.