INTRODUCTION: During root canal preparation; irrigants, dentin chips, pulp tissue and microorganisms may be extruded into the periradicular tissues which may cause postoperative pain and complications. OBJECTIVES: The aim of this study was to compare the amount of apically extruded debris in mesio-buccal canals of 30 extracted human mandibular molars instrumented with One-Shape file after preparing a proper glide path using G-files, ProGlider and K-files. MATERIALS AND METHOD: This study was conducted on the mesio-buccal roots of 30 human mandibular molars with curvature of 20 to 35 degrees. All specimens were divided into three groups according to the type of instrument used for glide path management. Group (1): manual instrumentation with K-files (#10, 15), Group (2): G-files: (G1: #0.12mm, G2: #0.17mm), and Group (3): ProGlider: single use rotary file. All teeth were instrumented using One-Shape file. Debris extruded apically from the teeth were collected into pre-weighed Eppendorf tubes. Three consecutive weights were obtained for each tube and the mean value was obtained. The weight of extruded debris was calculated as the difference between the pre and post instrumentation weights of the tubes. RESULTS: The highest amount of debris was found in the k-file group while the lowest amount with ProGlider group with significant differences between them. Moreover, significant difference was found between ProGlider and G -file while there was no significance between G-file and K -file groups. CONCLUSIONS: All techniques showed debris extrusion, although the use of NiTi rotary instruments may be rather beneficial.