Comparative evaluation of canal transportation and centering ability between 4% and 6% rotary files using cone beam computed tomography — An invitro study

Aim of the study was to evaluate the canal transportation and centering ability of 4% and 6% rotary systems by cone beam computed tomography (CBCT).: Sixty permanent mandibular first molar mesio-buccal canals were chosen and divided into two groups (n=30) according to the bio mechanical preparation method used: Vortex blue and XP Endo Shaper. Following after placed on a customized wax sheet substrate, the samples were scanned using CBCT and then subjected to instrumentation according to the group selected. Then post instrumentation CBCT was taken. Slices from the axial slice were obtained at 3 mm, 6 mm, and 9 mm from the root apex, corresponding to the apical, middle, and coronal thirds, respectively, from both exposures. The results showed that there were no statistically significant differences in canal centering and transportation between both the groups. However vortex blue group showed less transportation and less amount of untouched dentin. It was concluded that " 6% taper group though having higher taper showed better centering ability and less amount ofuntouched dentin and 4% taper file group thoughan adaptive core technology showed more transportation because of its non-uniform expansion to thermal changes.