Purpose: This in vitro study assessed the amount of debris extruded apically after preparation with different techniques.
Methods: Sixty healthy, extracted, human mandibular incisors were randomly divided into 3 groups: Group A - hand crown-down technique; Group B - crown-down technique with engine-driven rotary reciprocating instruments; Group C - Protaper: engine-driven continuous rotary instrumentation. The roots were immersed in 2.3 mL of distilled water. After preparation, the water in each tube was filtered to collect solid material extruded, and the filters were weighed using a precision scale. Data were analyzed by Kolmogorov-Smirnov and Kruskal-Wallis tests at the 0.05 level of significance.
Results: The statistical analysis showed that group C had significantly higher values of debris than groups A and B.
Conclusion: The instrumentation using a continuous rotary technique, Protaper, produced greater apical extrusion than the hand and engine-driven crown-down techniques. The direction of instrumentation, whether cervical-apical or apical-cervical, seems to be a more important factor influencing apical extrusion than whether the instrumentation was performed by hand or was engine-driven.