Effect of different obturating techniques and sealers on the removal of filling materials during endodontic retreatment

Background: Adequate removal of previous root filling materials is an important objective during endodontic retreatment. Aim: This study was aimed to evaluate the influence of obturation quality and sealer type on the removal of root filling materials during endodontic retreatment using micro-computed tomography (μ-CT). Materials and Methods: Ninety extracted mandibular premolars were randomly assigned to two groups (n = 45) based on the type of sealer (AH Plus and BioRoot RCS) and three sub-groups based on the obturating technique used, i.e., cold lateral condensation, warm vertical compaction, and thermoplasticized injectable techniques. Specimens were scanned using μ-CT before and after retreatment to assess the amount of filling material, and time taken for removal was recorded. Statistical Analysis: Data were analyzed using two-way analysis of variance and Tukey's multiple post hoc test at 5% significance level. Results: Filling debris percentage and retreatment time were not significantly affected by the type of sealer (P ≥ 0.05). The percentage of remaining filling material was higher in teeth obturated with thermoplasticized technique (P < 0.05). Significantly more filling material debris was observed in apical third (P < 0.05). Conclusions: The type of obturating technique used for initial root canal treatment has influenced the amount of remaining filling material and retreatment time. Retreatability of the BioRoot RCS sealer was similar to the AH Plus sealer.