(PO41) Evaluation of the Efficacy of Four Different Solvents on a Calcium Silicate-based Sealer During Endodontic Retreatment: An Ex vivo Study

Abstract: This study evaluated the efficacy of four different solvents on a calcium silicate-based sealer (CSS). Eighty-three extracted teeth with a single straight root were decoronated to achieve a standardized root length. Following access, patency was achieved with a #15 K-file, and the canals were instrumented to an apical size 35/.04, intentionally 2 mm short of the working length, using rotary files. The canals were obturated using a single-cone technique with CSS (Brasseler) and gutta-percha. Radiographs confirmed that the apical 2 mm was filled with sealer. The roots were stored in HBSS for seven days at 37°C and 100% humidity. Sixty-one samples were randomly divided into four groups: acetate buffer, pH 4 (AH4); 17% EDTA (EDTA); EDTA buffer, pH 10 (EH10); and deionized water (DW). The teeth were retreated by removing the cones without solvent and attempting to regain patency with a #10 K-file using 0.1 mL of the respective solvent for each group, refreshing it every three minutes. The time needed to achieve patency and the volume of the solvent used were recorded. The inability to achieve patency within 15 minutes was recorded as a failure. ANOVA was used to analyze the patency rates, times, and volumes (p < .05). The patency rates were: AH4 33.3%, EDTA 45.5%, EH10 66.7%, and DW 36.3%. There were no significant differences in patency rate, time, and volumes among the four groups. None of the test solvents were significantly more effective in regaining patency than deionized water; however, EH10 showed potential as a solvent and merits further exploration.