Endomotor integration, file kinematics impact on apical debris extrusion in severely curved canals

Aim: This study aimed to quantify and compare the apically extruded debris during root canal instrumentation of severely curved canals using rotary and reciprocating file systems with integrated and nonintegrated endomotors. Methods: Sixty freshly extracted single canal maxillary and mandibular teeth with severe curvature (>20°) were decoronated and standardized to an 18 mm root length. Teeth were equally divided into four groups ( n = 15) based on the type of endomotor (integrated or nonintegrated) and file kinematics (rotary or reciprocating). Root canals were instrumented using ProTaper Gold F2 and WaveOne Gold Primary files, following a crown-down technique. Debris was collected using a modified Myers and Montgomery model and quantified by preand postinstrumentation vial weight differences after incubating samples at 70°C for 5 days. The one-way analysis of variance test was used with P < 0.05. Results: All groups exhibited some debris extrusion (maximum 0.3469 ± 0.0335 in the nonintegrated rotary group and minimum 0.3155 ± 0.0626 in the integrated reciprocation group). Integrated endomotor groups extruded significantly less debris. Furthermore, rotary motion resulted in greater debris extrusion than reciprocating motion ( P > 0.05). Conclusion: The findings suggest that integrated endomotors and reciprocating file systems are advantageous in minimizing apical debris extrusion in severely curved canals. The study highlights the importance of endomotor design and kinematic motion in influencing debris extrusion.