Introduction: To compare the apical extrusion of debris produced during root obturating material removal from severely curved root canals using either Reciproc (REC) or ProTaper Next (PTN) systems. Methods and Materials: Twenty-six mesial canals of lower molars were instrumented, filled and allocated into two groups (n=13). Micro-computed tomographic images were performed to determine the root canal configuration (Vertucci’s type IV) and initial volume of obturation. One Eppendorf tube was assigned per canal and weighed (10-4g) before and after removal of the obturating material. The difference between the initial and final weights was calculated and statistically evaluated. Results: Apical extrusion of debris was confirmed in all samples, and the mean amount of apical extrusion was similar between both groups (0.061±0.014 g in PTN vs. 0.065±0.016 g in REC samples) (P<0.05). Conclusion: Both systems caused apical extrusion of debris with no differences between PTN and REC systems.