Comparison of the amount of apically extruded debris during retreatment using different nickel-titanium systems and hand instruments in teeth with wide apices

Objective: The purpose of this study was to compare the apically extruded debris during endodontic retreatment of teeth with open apices using hand instruments and rotary instruments with continuous rotation and reciprocation. Methodology: Forty-five single-rooted maxillary incisors and canines were used. The root tips were dissected and #1 Gates Glidden burs were allowed to protrude 1 mm beyond the apex. After root canal shaping and filling using AH Plus and gutta-percha, the teeth were randomly divided into 3 groups (n=15). Removal of filling was performed as follows: Group 1: ProTaper Universal-Retreatment files using continuous rotation + ProTaper Universal files Group 2: K-type hand files Group 3: Reciproc files using the reciprocating motion. The extruded debris was collected in glass vials. The weight of the collecting vials was measured before and after instrumentation using a microbalance and the difference was recorded as the amount of extruded debris. The data were statistically analysed using Kruskall Wallis and Bonferroni corrected Mann Whitney U test. Results: Statistical analysis showed that the amount of extrusion was significantly less in rotary systems compared to hand instruments and reciprocating systems (p<0.05). On the other hand, the amount of extrusion in the reciprocating group was significantly lower compared to hand instruments (p<0.05) Conclusion: The amount of extrusion in Ni-Ti instruments using a continuous rotation was significantly lower compared to hand instruments and Ni-Ti instruments using a reciprocating motion in teeth with