ABSTRACT
The success of root canal therapy requires effective cleaning and shaping of canals. The present study was conducted to compare canal transportation and centric ability of CM and WO file system. Methods: The present study was conducted on 40 recently extracted mandibular premolars of both genders. The teeth were randomly divided into 2 groups. In group I, teeth were prepared using HyFlex CM files up to 25/0.4 and in group II, teeth were prepared using WO files up to 25/0.8.The amount of canal transportation was evaluated by measuring the shortest distance from the edge of uninstrumented canal to the periphery of the root (mesial and distal) and then comparing this with the same measurements obtained from the instrumented images. The mean centering ratio indicates the ability of the instrument to stay centered in the canal. Results: Canal transportation was small in group I as compared to group II at 3mm, 9mm and 12 mm. The difference was significant (P< 0.05). The mean centric ratio in group I was 0.394 at 3 mm, 0.311 at 9 mm and 0.459 at 12 mm. In group II, it was 0.514 at 3 mm, 0.501 at 9 mm and 0.782 at 12 mm. The difference was significant (P< 0.05). Conclusion: Canal preparation with HyFlex CM file system showed lesser transportation and better centering ability than WO file system.