Assessment of apical deviation of root canals after debridement with the Hybrid, ProTaper and PathFile systems

Aim: To assess the occurrence of apical transportation of mesio-vestibular canals of mandibular molars using two rotary techniques and one hybrid technique during shaping and cleaning. Materials and Methods: Forty-five human mandibular molars with a degree of mesial canal/root curvature of 20° to 55° were selected, which were included in acrylic resin blocks and randomly separated into three groups. Group 1-Fifteen teeth were debrided using the ProTaper rotary technique; Group 2-Fifteen teeth were debrided using the Manual Hybrid and ProTaper rotary technique; Group 3-Fifteen teeth were debrided using the PathFile-ProTaper technique. Apical deviation was assessed by the radiographic platform method that enables obtaining superimposed images of the first and last instrument used in root canal preparation in the same radiograph. Apical transportation was measured in millimeters with the aid of the Adobe Photoshop CS4 software. Results: The mean deviation for Group 1 was 0.03 mm, for Group 2, 0.1 mm and for Group 3, 0.08 mm. Statistical analysis (Kruskal-Wallis test) of the results demonstrated that there was no statistically significant difference among the samples ( P >0.05) with regard to the apical deviation. Conclusion: The techniques provided minimum apical deviation.