Dimensional and cross-sectional compatibility of contemporary nickel–titanium files and their corresponding gutta-percha cones: A micro-computed tomography study

This study aimed to evaluate the dimensional and sectional compatibility between contemporary nickel–titanium (NiTi) root canal instruments and their corresponding gutta-percha (GP) cones with variable tapers, and to assess their compliance with ISO and ADA standards using micro-computed tomography (Micro-CT). Four NiTi file systems (ProTaper Next X2, HyFlex EDM OneFile, Reciproc Blue R25, and WaveOne Gold Primary) were analyzed. Their compatibility with corresponding GP cones was assessed based on diameter and taper measurements at 1 mm intervals (D1 to D16). Measurements were performed using Micro-CT imaging, and data were analyzed using descriptive statistics, independent t-tests, and one-way ANOVA with Bonferroni post hoc tests (p<0.05). Compliance with International Organization for Standardization (ISO) and American Dental Association (ADA) standards was also assessed. The findings reveal significant dimensional discrepancies between files and GP cones, with GP cones generally exhibiting larger diameters. Reciprocating systems (WaveOne Gold and Reciproc Blue R25) demonstrated superior compatibility with GP cones compared to rotary systems (ProTaper Next and HyFlex EDM OneFile). GP cones adhered more closely to ISO and ADA standards than files. Significant mismatches were identified between NiTi instruments and their corresponding GP cones. Reciprocating systems showed better dimensional compatibility than rotary systems. These results highlight the need for careful evaluation of material pairing to ensure optimal clinical performance.