Assessment of Apical Extrusion using Rotary and Reciprocating Systems during Root Canal Retreatment.

AIM: The objective of this study was to assess apical extrusion after filling material removal using two systems, one rotary and one reciprocating. MATERIALS AND METHODS: A total of 34 extracted mandibular premolars with single roots were selected and, posteriorly, prepared and filled. Following material aging for 60 days, teeth were divided into two groups, according to the method used to remove root filling material: group I, ProTaper(R) Universal Retreatment instruments plus refining with the Hero 642(R) sequence and group II, WaveOne(R) instruments. The teeth were fixed in an apparatus designed to collect the extruded material during removal procedure. Data on the amount of debris extruded (mg/weight) were analyzed using the Student's t test with a significance level of 5%. RESULTS: No significant differences were found between the groups with regard to the amount of material extruded during root canal retreatment. CONCLUSION: The present findings suggest that the extrusion of debris during apical root canal retreatment does not depend on the instrument design or the protocol employed. CLINICAL SIGNIFICANCE: Regardless of root canal clearance techniques, debris extrusion eventually occurs during endodontic retreatment and may be related to postoperative pain.