Shaping ability of 4 different single-file systems in simulated S-shaped canals

Introduction: The aim of this study was to compare the shaping ability of 4 different single-file systems in simulated S-shaped canals. Methods: Sixty-four S-shaped canals in resin blocks were prepared to an apical size of 25 using Reciproc (VDW, Munich, Germany), Wave- One (Dentsply Maillefer, Ballaigues, Switzerland), One- Shape (Micro Méga, Besançon, France), and F360 (Komet Brasseler, Lemgo, Germany) (n = 16 canals/ group) systems. Composite images were made from the superimposition of pre- and postinstrumentation images. The amount of resin removed by each system was measured by using a digital template and image analysis software. Canal aberrations and the preparation time were also recorded. The data were statistically analyzed by using analysis of variance, Tukey, and chi-square tests. Results: Canals prepared with the F360 and One- Shape systems were better centered compared with the Reciproc and WaveOne systems. Reciproc and WaveOne files removed significantly greater amounts of resin from the inner side of both curvatures (P < .05). Instrumentation with OneShape and Reciproc files was significantly faster compared with WaveOne and F360 files (P < .05). No instrument fractured during canal preparation. Conclusions: Under the conditions of this study, all single-file instruments were safe to use and were able to prepare the canals efficiently. However, single-file systems that are less tapered seem to be more favorable when preparing S-shaped canals.