Comparative evaluation of nickel titanium rotary instruments on canal transportation and centering ability in curved canals by using cone beam computed tomography: An in vitro study

Abstract

The aim of this study was to compare canal transportation and centering ability of different nickle titanium systems using Cone beam computed tomography in curved canals. Ninety mandibular molars with angle of curvature ranging from 10°– 40° were randomly allocated into six experimental groups containing 15 teeth in each group. Preinstrumentation scans were taken with CBCT with constant exposure parameters before and after instrumentation. Six grouped specimens were instrumented with Wave One, Twisted File, Hyflex CM, K3XF, ProTaper Next, NeoNiTi file respectively. Post instrumentation the specimens were scanned by CBCT to obtain postoperative images. The amount of root canal transportation and centering ability of the instrument were determined. Statistical analysis on collected data was performed using One way analysis of ANOVA, and post-hoc Tukey test (p<0.0.5). K3XF group showed significantly higher transportation values in the apical third (2mm) than TF group (p=0.01) and Hyflex CM group (p=0.03). The coronal transportation values are higher than the apical values but with no significant difference between them (p>0.05). There was no significant difference in centering ratio values between the six groups (p>0.05) at any of the level.: All the file systems can be safely used, showing satisfactory preservation to the original canal shape with preference of TF files.