Microcomputed tomographic evaluation of 6 NiTi files on the pericervical dentin and the smallest dentin thickness zones in mesial root canals of mandibular molars: An in vitro study

Objectives: The aim of this study was to evaluate six files on the pericervical dentin (PCD) and the smallest dentin thickness zones (SDTZ) in mesial root canals of mandibular molars. Materials: and Methods Sixty mesial roots with 2 canals were scanned before and after instrumentation with WaveOne Gold (WG), Reciproc Blue (RB), TRUShape (TS), XP-endo Shaper (XP), iRace (IR), and TruNatomy (TN). Surface, volume, structure thickness, SMI, and centroids were evaluated at the PCD, and the changes in the SDTZ were quantified. The data obtained werecompared using Wilcoxon and ANOVA with a 5% significance level. Results: : XP and TN were similar in all the parameters (P >.05) at the PCD, but TN showed significant differences from WG, RB, TS, and IR (P <.05), while XP showed significant differences from WG (P <.05) in volume, surface, and structure thickness. Regarding the changes in the SDTZ, the amount of dentin removed was similar between the groups in both canals at the middle 1/3, at the cervical 1/3 for MB canals, and in ML canals for RB, TS, XP, IR, and TN (P>.05). The action of WG was significantly different from that of XP and TN in the cervical 1/3 of the ML canal (P <.05). Conclusions: XP and TN maintained better the anatomy, with minor changes at the PCD and SDTZ, while WG produced the largest changes. Centering at the PCD was maintained with all the files, and their performances were safe without risk of perforation. Clinical Relevance The choice of endodontic files is a relevant factor in the conservative performance of root canal treatments. Trial Registration: No clinical trials were indicated in this study