Assessment of mechanical root canal preparation with centric reciprocating or eccentric rotary kinematics: a micro-computed tomography study.

Abstract Introduction The aim of this study was to compare, using micro-computed tomography, the preparation of mesial canals of mandibular molars with the Reciproc and XP-endo Shaper systems, evaluating changes in dentin and canal volume, the percentage of untouched walls, the volume of accumulated hard tissue debris and root canal deviation in the apical third. Methods Twenty-four mandibular molars with two mesial root canals and a single foramen were anatomically paired and divided into two experimental groups (n=12) according to the system used. The specimens were scanned before and after preparation with a SkyScan 1176 microtomograph (Bruker-microCT, Kontich, Belgium) at a resolution of 17.42 μm. The resulting data were statistically compared at a significance level of 5% using Student's t-test and the Mann-Whitney test. Results A significant difference was observed in untouched surface area for the total canal and for the cervical and middle thirds, with the lowest untouched surface area in the XP-endo Shaper group (P 0.05). Conclusion The XP-endo Shaper touched more walls and left less accumulated hard tissue debris in the root canal system than did the Reciproc system.