(PR008) Effectiveness of a Novel Solvent for Removing Calcium Silicate-based Root Canal Sealer: An Ex Vivo Study

Objective(s): The use of calcium silicate-based root canal sealers (CSS) is becoming prevalent in endodontic treatment. However, in retreatment no solvent has yet proven effective for CSS removal. This study aimed to evaluate the effectiveness of a novel EDTA-based solvent on CSS removal.

Methods: Extracted human teeth were collected and decoronated and 79 roots with a single canal were endodontically treated. After achieving apical patency with a #10 K-file, the canals were instrumented to size 30/.04 2mm short of the apex and obturated using a single gutta-percha cone and BC Sealer HiFlow. After storage in HBSS at 37^oC for 18 days, the samples were randomly divided into 4 groups: pH 10 buffered EDTA (EH10); 17% EDTA (EDTA); deionized water (DW); and a control group with no solvent. The samples were then retreated using ProTaper retreatment files (600r/min and 2.0N cm) and patency was regained with #15 and #20 K-files using 0.5 mL of the respective solvent in each group. The success rate of regaining patency and the time to achieve patency were recorded. Data were analyzed using one-way ANOVA and Tukey post-hoc tests (p < 0.05).

Results: Patency success rates of EH10, EDTA, DW and control were 63%, 45%, 30%, 20%, respectively. The difference between EH10 and the control group was statistically significant (p=0.043). There were no significant differences in time to achieve patency across all groups.

Conclusion: EH10 showed the highest patency rate and may be an effective solvent for retreating cases filled with CSS. Further study is warranted to determine its clinical efficacy.