Comparative evaluation of the shaping ability of rotary systems of varying metallurgy in curved canals and its analysis using cone-beam computed tomography: An in vitro study

Abstract

Background: This study compared the shaping ability of four nickel-titanium rotary file systems of varying metallurgy along curved canals. Aim: The aim of the present study is to compare the shaping ability of rotary systems of varying metallurgy in curved canals and its analysis using cone-beam computed tomography (CBCT). Materials and Methods: Forty mesiobuccal canals of mandibular first molars with an angle of curvature ranging from 20° to 40° were divided according to the instrument used in canal preparation into four groups of 10 samples each: Hyflex CM (Group I), Vortex Blue (Group II), Flexicon (Group III), and K3XF (Group IV). All samples were instrumented according to the manufacturer's guidelines and prepared to size 30, 0.06-taper master apical file. Canals were scanned and evaluated using an NNT CBCT unit before and after preparation at different levels from the apex. The data were subjected to statistical analysis. Statistical Analysis: The intergroup comparison in terms of canal transportation and the time taken for canal preparation was done by the one-way analysis of variance (ANOVA) test with Bonferroni post hoc test. The intragroup comparison in terms of canal transportation was done by the repeated measures ANOVA test with the post hoc Bonferroni test. For the canal-centering ability, the Kruskal–Wallis test with Mann–Whitney U-test was used for the intergroup comparison and the intragroup comparison was done by Friedman's test with Wilcoxon signed-rank test. Results: Hyflex CM and Vortex Blue files showed significantly least canal transportation and highest canal-centering ability values as compared to Flexicon and K3XF file systems. Conclusion: The metallurgy and file design of Hyflex CM and Vortex Blue file systems resulted in superior shaping ability, with the instruments remaining more centered in the canal than Flexicon and K3XF.