(PR32) Retreatability of Calcium Silicate-based Root Canal Sealer with Chloroform and Eucalyptol Oil in the Curved Root Canals

Abstract: The aim was to evaluate the efficacy of chloroform (CF) and eucalyptol oil (EO) in removing single gutta-percha cones and calcium silicate-based root canal sealer from curved root canals. Forty-four extracted human molars were scanned using cone beam-computed tomography. 113 canals were traced to measure their curvature using Planmeca Romexis®. The curved canals were evenly distributed into four groups. Canals were instrumented 2 mm short from the working length to size 30/0.04. Apical patency was confirmed with a #10 Flexofile® 1 mm past the anatomical apex. Single-cone obturation with Endosequence® BC Sealer™ was completed and stored at 37°C in 100% humidity using Hanks’ balanced salt solution for one month. Retreatments were implemented to regain patency using ProTaper Gold® files S2/S1 (PTG) with CF, PTG with EO, XP-3D shaper™ file (XP3D) with CF, and XP3D with EO. The inability to achieve patency within twenty minutes was recorded as a failure. ANOVA Likelihood-Ratio test was used to compare the rates of gaining patency and mock chair-times. Patency was reestablished in 107 canals (patency rate > 92.6% in all groups). CF had an effect on decreasing the chair-time when used with PTG as compared to CF with XP3D, whereas EO did not (p < 0.05). There was no statistical significance in the ability to regain patency among different types of rotary files or solutions. A combination of PTG with CF for retreatment demonstrated statistically better time-efficiency compared to other combinations in the study.