Bonding of resin-based sealers to root dentin.

This study compared the microshear bond strength of three resin-based sealers to root dentin and assessed whether sealer cements behave differently in thin and thick films. Extracted maxillary premolars were sectioned buccolingually, and 45 root halves were randomly allocated for microshear bond testing with the three resin sealers in thin and thick films. The microshear bond strength was then calculated in MPa. Failure modes were examined under light and scanning electron microscopy. Data were analyzed by using analysis of variance, with significance set at p < 0.05. Overall, the epoxy resin-based sealers had the highest microshear bond strength to root dentin compared with urethane dimethacrylate-based sealers (p < 0.001). Bond strengths for the thick sealer group were significantly higher than the thin sealer group (p < 0.001) and may reflect different patterns of behavior when the sealer is present as a thin layer.