Aim: compared the effect of continuous rotation and optimum torque reverse on the amount of apically extruded debris using EdgeFile X7 and Endostar E3 Azure files. Materials and Methods: Forty extracted mandibular premolars with single straight canals were chosen. Canals were divided into two equal groups (n=20) according to kinematics; Group (I): continuous rotation, Group (II): optimum torque reverse. Each group was further subdivided into two equal subgroups (n=10) according to the type of rotary file system employed in root canal preparation: Sub-group A: Endostar E3 Azure files, Sub-group B: EdgeFile X7.
Canals were prepared and extruded debris from each sample was collected in pre-weighted Eppendorf tubes and dried. The weight of debris was assessed by an analytical microbalance. Data were statistically analyzed by two-way ANOVA test. Results: According to motion kinematic; with continuous rotation EdgeFile X7 had higher value than Endostar E3 Azur while with Optimum torque reverse motion, Endostar E3 Azur had higher value with no statistically significant differences. According to file used, EdgeFile X7 showed higher significant value with continuous rotation than with optimum torque reverse. While Endostar E3 Azur showed a higher value with continuous rotation than with optimum torque reverse with no statistically significant difference. In comparing file motion in relation to the file type used; continuous rotation has a significant higher mean value than optimum torque reverse. Conclusion: kinematics has an impact on the amount of extruded debris regarding the type of rotary files used.