Influence of Drying Techniques on Dentin Bond Strength: A Comparative Study of Three Endodontic Sealers with Single-Cone Obturation.

Background: The moisture condition of the root canal can significantly influence the bond strength of endodontic sealers, which is critical to the long-term success of root canal therapy. While the single-cone obturation technique is widely used, the effect of different canal drying protocols on the adhesion of various sealers remains unclear. Aim: This study aimed to evaluate the effect of two drying protocols, paper points and 95% alcohol, on the push-out bond strength of three sealers: AH Plus, GuttaFlow 2, and RealSeal SE, when used with the single-cone technique. Materials and Methods: Sixty extracted maxillary central incisors were decoronated and instrumented, then divided into two main groups based on drying protocol. Each group was further divided into three subgroups according to sealer type. Push-out bond strength tests were performed at the coronal, middle, and apical levels. Failure modes were examined, and data were analyzed using two-way ANOVA. Results: Both the drying method and canal region significantly affected bond strength (p<0.001). Although the sealer type alone was not a significant factor, a significant interaction existed among sealer type, drying method, and canal level. Alcohol drying resulted in higher bond strengths across all sealers. GuttaFlow 2 showed the highest bond strength in the alcohol group, while RealSeal SE performed best in the paper point group. Apical sections exhibited the highest bond strengths overall. Cohesive failures were more common with alcohol drying, whereas adhesive failures predominated with paper point drying. Conclusions: Drying protocol has a significant impact on sealer adhesion. Alcohol (95%) drying enhances bond strength and may improve clinical outcomes, particularly when used with GuttaFlow 2.