Effect of Post-Endodontic Cleaning Protocols on Sealer Bond Strength and Tubule Penetration

Background: It was aimed to evaluate the effect of different cavity cleaning techniques on the bond strength and dentinal tubule penetration of an epoxy resin-based root canal sealer in sealer-contaminated cavities. Methods: Thirty-five extracted mandibular premolars were prepared and obturated with AH Plus sealer labeled with 0.1% rhodamine B. The teeth were randomly divided into 5 groups according to the post-obturation cleaning technique: (1) no cleaning, (2) dry cotton pellet, (3) 70% ethanol, (4) ethanol + air polishing with sodium bicarbonate, and (5) air abrasion with aluminum oxide. The coronal 1 mm sections of the roots were obtained to assess push-out bond strength and sealer penetration using confocal laser scanning microscopy. Results: No statistically significant difference was found among the groups in terms of bond strength (P = .655) and dentinal tubule penetration (P = .122). However, higher bond strength values were observed in the air polishing group. Conclusions: None of the evaluated cavity cleaning protocols demonstrated a statistically significant advantage over the others regarding dentinal tubule penetration and push-out bond strength. However, air polishing showed a trend toward higher bond strength values. The trend toward improved bond strength with air polishing suggests that this method may enhance sealer adhesion to dentin and contribute to a more durable coronal seal in clinical practice.