(PO81) A Facile Method for Rejuvenating the Bonding Efficacy of Root Canal Sealer-Smeared Dentin

Abstract: To evaluate the efficacy of glycine powder air-polishing in cleaning root canal sealer-smeared dentin, dentin surfaces were contaminated with a smear of either AH Plus (Dentsply Sirona, an epoxy resin-based sealer) or iRoot SP (Innovative BioCreamix Inc, a tricalcium silicate-based sealer). The contaminated surfaces were then cleaned using saline scrubbing, 75% ethanol scrubbing, or air-polishing with glycine powder. The control group consisted of uncontaminated dentin surfaces. The cleanliness of the pulpal floor dentin was examined using scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX). The effectiveness of the three cleaning protocols was assessed by testing the tensile bond strength of a self-etching adhesive to the decontaminated dentin. Resin infiltration into the dentinal tubules was identified using confocal laser scanning microscopy (CLSM). Morphological examination and elemental analysis showed that glycine powder air-polishing was more effective in removing the two types of sealers from the dentin. Tensile bond strength of adhesive-bonded dentin was significantly reduced when either sealer was scrubbed with saline or ethanol. However, air-polishing actually restored the adhesive strength of the sealer-smeared dentin to the level of the control. Longer and denser resin tags were identified with CLSM when sealers were removed with air-polishing. Air-polishing with glycine powder proved effective in cleaning sealer-smeared dentin, as demonstrated by the restored tensile bond strength of a self-etching adhesive to the decontaminated dentin.