Effect of chemical and Er:YAG laser treatment on bond strength of root canal resin-based sealers.

Different treatments of dentin walls, as laser irradiation, prior to obturation can influence the adhesion ability of endodontic sealers. Therefore, the objective of this study was to compare in vitro the shear bond strength of four resin-based sealers to dentin treated with citric acid solution or erbium: yttrium, aluminum, garnet (Er:YAG) irradiation. A total of 240 slices with 1.6 mm of thickness were cut using middle third of 84 teeth. Each slice was widened using a #45 taper.06 rotary K3 instrument. The sample was divided into groups according to dentin pretreatment (15 % citric acid or Er:YAG laser) and sealer used (AH Plus, Acroseal, EndoREZ, or RealSeal). Shear bond strength was measured using a universal materials testing machine. As results, significant differences were found when comparing sealers between all groups (p < 0.05) by Kruskal-Wallis test, regardless of the pretreatment used. Comparing pretreatments, 15 % citric acid solution had better outcomes than Er:YAG laser, with significant differences in all groups, except for Acroseal groups (p < 0.05). It was concluded that RealSeal and 15 % citric acid solution achieved the best results regarding the sealer and pretreatment used, respectively.