Evaluation of irrigation techniques in the removal of root canal filling material: Micro-CT and SEM study

Background/Aim: This study aimed to compare the different irrigation activation methods in retreatment of oval-shaped root canals. Material and Methods: Forty distal canals from mandibular molars were filled. After the removal of filling material, specimens were assigned to four groups as follows; control, passive ultrasonic irrigation (PUI), self-adjusting file (SAF), and XP-endo Finisher (XPF). The amount of residual filling material was assessed by micro-computed tomography (micro-CT) and root canal walls were examined by using scanning electrom microscopy (SEM). Data were analyzed using the Kruskal-Wallis and Dunn test. Results: None of the activation techniques removed root canal remnants completely. The amount of filling material significantly decreased in all activation techniques compared to the control group (p<0.05). There was no significant difference between the PUI, SAF, and XPF groups in the micro-CT analysis (p>0.05). SEM evaluation showed higher scores in the apical region in all groups (p<0.05). Conclusions: The use of activation methods reduces the amount of residual filling material.