Objective: To evaluate the effect of pre-procedural antiseptic mouthwashes on dentin bond strength of different adhesive systems.
Methods: Flat occlusal dentin surfaces from 120 extracted human molars were randomly divided into four groups according to mouthwashes (0.12% chlorhexidine = CHX, 1% hydrogen peroxide = HP, 0.2% povidone-iodine = PI, and no mouthwash/control) and three subgroups of adhesives used (Clearfil SE Bond; CSE, Single Bond Universal = SBU in etch-and-rinse (ER) or self-etch (SE) modes) (n = 8). Composite resin was built up, and all bonded teeth were stored in 37°C distilled water for 24 h. Stick-shaped specimens were prepared and subjected to microtensile bond strength (µTBS) test. Failure mode analysis was determined using a light microscope. A resin-dentin interface was observed using scanning electron microscopy (SEM, n = 2). Elemental analysis in the PI group was further examined by SEM with energy-dispersive X-ray spectroscopy. The µTBS data were statistically analyzed by two-way analysis of variance (ANOVA) and Duncan’s multiple comparison (P < 0.05).
Results: Rinsing with PI followed by SBU-SE demonstrated significantly higher µTBS than the control group (P < 0.05). Rinsing with HP showed significantly lower bond strength for CSE (P < 0.05). However, the effect of adhesive systems was not observed for all mouthwashes used (P > 0.05). SEM/EDX revealed the iodine deposition in the underlying dentin, where the highest amount of iodine was found for SBU-SE.
Conclusion: CHX and PI can be recommended as pre-procedural antiseptic mouthwashes since they show no negative impact on µTBS for all tested adhesives. The dentin bond strength of CSE is hampered in the HP mouthwash group, and this should be a concern for the use of self-etching adhesive afterward.