Shaping Ability of 4 Different Single-file Systems in Simulated S-shaped Canals

• We evaluated the shaping ability of 4 single-file systems in simulated S-shaped canals.
• Files that are less tapered seem to be more favorable.
• OneShape and Reciproc were shown to be faster than WaveOne and F360.
• WaveOne and Reciproc should be used with care in canals with severe curvature.

IntroductionThe aim of this study was to compare the shaping ability of 4 different single-file systems in simulated S-shaped canals.MethodsSixty-four S-shaped canals in resin blocks were prepared to an apical size of 25 using Reciproc (VDW, Munich, Germany), WaveOne (Dentsply Maillefer, Ballaigues, Switzerland), OneShape (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.ResultsCanals prepared with the F360 and OneShape 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.ConclusionsUnder 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.