Comparison of torque, force generation and canal shaping ability between manual and nickel-titanium glide path instruments in rotary and optimum glide path motion

This study aimed to analyze force/torque generation and canal volume changes of NiTi rotary glide path preparation using HyFlex EDM Glide Path File in comparison to manual stainless steel K-file instrumentation. Thirty extracted mandibular incisors with a minimally curved and narrow root canal were randomly divided into three groups (n = 10) according to the instrumentation kinematics: Optimum Glide Path motion (OGP) or continuous rotation (CR) with HyFlex EDM Glide Path Files using a custom-made automated-root-canal-preparation device and manual instrumentation with stainless steel K-files (SS) in watch-winding motion. Torqu e and force were monitored with a custom-made torque/force analyzing device. Canal volume changes and transportation values were measured on micro-computed tomographic images taken before and after the glide path preparation. The data were statistically evaluated using Kruskal–Wallis test and Mann –WhitneyU test with Bonferroni correction, with a significance level set at 5%. Maximum upward apical force, representing the screw-in force, was lower in groups OGP and CR compared with that in group SS (P <  0.05). Group CR showed the highest maximum clockwise torque value and canal volume changes, followed by groups OGP and SS (P <  0.05). Canal transportation values at 1 and 3 mm from the apex were not significantly different among groups. Within the limitations of this study, rotary glide path preparation generated smaller screw-in f...

Source: Odontology - September 9, 2019 Category: Dentistry Source Type: research