Canal transportation and centering ability of HyFlex CM and TruNatomy rotary file systems in moderately curved root canals using CBCT: An in vitro study

ABSTRACT Aim: The objective of this study was to evaluate and compare canal transportation (CT) and centering ability (CA) in the curved canals prepared using HyFlex CM (HCM) and TruNatomy (TN) rotary file systems with the help of cone-beam computed tomography (CBCT). Materials and Methods: Forty extracted single-rooted mandibular premolars with 10°–30° of curvature were selected and divided into two groups. In Group 1, the canals were prepared with HCM files (Coltene Whaledent) and in Group 2 the canals were prepared with TN Prime rotary files (Dentsply Sirona). Pre- and postinstrumentation scans were performed at the same position using CBCT to evaluate CT and CA at three levels 3 mm, 6 mm, and 9 mm from the apex and were compared using CBCT software (On Demand 3D software). Statistical Analysis Used: The two groups were statistically analyzed with Mann–Whitney U -test. Results: There was no significant difference among the tested groups regarding the canal centering ratio ( P > 0.05). At 6- and 9-mm levels, there was no significant difference in CT among the two groups ( P > 0.05). However, at 3 mm from apex, there was a statistically significant difference ( P = 0.006) with TN files exhibiting lesser CT. Conclusion: Both the file systems respected the canal anatomy, although in the apical third, TN files exhibited better results. Hence, this file system can be considered for instrumentation of canals with moderate apical curvatures. In regard to CA, no significant differences were found among the file systems.