Evaluation of canal patency and cleanliness following retreatment of bioceramic sealer-obturated root canals using three different irrigant activation protocols.

This study evaluated the effectiveness of three different irrigant activation techniques in cleaning and establishing patency during retreatment of root canals obturated with gutta-percha and bioceramic sealer. 60 extracted premolars with oval-shaped canals were instrumented and obturated with gutta-percha and EndosequenceBC sealer using the 'warm hydraulic condensation' technique. The teeth were retreated using Protaper Universal Retreatment and XP-Endo Shaper system and divided into four groups according to the irrigant activation protocol used: control, passive ultrasonic irrigation (PUI), Endovac irrigation (EVI) and XP-Endo Finisher R (XPFR). Apical patency was achieved in all the samples of the XPFR group (100%), which showed a significantly higher success rate compared with the control (73.3%) and EVI groups (73.3%) (p < 0.05). The scanning electron microscopic evaluation revealed significantly cleaner middle and apical third root canals in the PUI and XPFR groups compared with the control group (p < 0.05). These findings suggest that XPFR effectively cleans and establishes patency in root canals filled with bioceramic sealers.