Endodontic instruments, while performing, is expected to remain centered in root canal to prevent apical transportation. Hence assessment of centering ability of newer rotary NiTi file systems becomes essential for effective cleaning & shaping. Aims and objectives: Comparative CBCT evaluation of apical transportation and centering ability of Protaper Next, Hyflex CM and Twisted file. Material and Method: Total of 24 extracted maxillary first molars were collected, randomly and equally divided

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... to three following groups-Gr A, Gr B, Gr C (n=8). Every tooth was embedded into the wax block maintaining the groups and pre instrumentation CBCT was done. After that the MB canals were instrumented by Protaper-Next in Gr A, Hyflex CM in Gr B and Twisted file In Gr C respectively and irrigated by 2.5%NaOCl and 17%EDTA during and after preparation. Then teeth were subsequently re-embedded into the wax block maintaining the groups and post instrumentation CBCT was done. The pre and the post procedural scan images were analyzed and compared for the changes. Result: Mesio-distally TF files showed least apical transportation with highest centering ability and bucco- lingually HCM showed the same observation. In both directions PTN showed apical highest transportation and lowest centering ability. Conclusion: Canal transportation and centering ability of instruments in curved canals when compared then it was revealed that mesio-distally Twisted files and bucco-lingually Hyflex CM file exhibited better centering and minimum or nil transportation.