Centering ability of a new nickel-titanium rotary instruments with a peculiar flat-side design: an in vitro study

AIM: The aim of the present study was to investigate the role of the flat design compared with a non-flat designed instrument on the centering ability in a simulated root canal system. MATERIALS AND METHODS: Two file systems were chosen: the F-One (Fanta Dental, Shanghai, China) and a prototype with the same design but without the flat-side design. A total of 50 simulated L-shaped root canals in resin blocks were shaped with a new instrument each. Pre- and postcanal preparation images were captured and superimposed to measure and compare the canal transportation and evaluate the centering ability of each file. The t test was performed and the level of significance was set at p < 0.05. RESULTS: Prototype files removed significantly less resin from the inner and the outer parts of the canal and showed significantly higher mean transportation values. CONCLUSION: It can be concluded that the F-One file system demonstrated better shaping ability compared with the prototype file system in L-shaped resin-simulated canals. CLINICAL RELEVANCE: The present study showed the safety of the flat-side design, minimizing the risk of iatrogenic errors such as ledging, perforation, or zipping of the root canal.