Shaping Ability of HyFlex EDM and ProTaper Next Rotary Instruments in Curved Root Canals: A Micro CT Study.
AIM The aim of this study is to evaluate and compare the shaping ability of HyFlex(tm) EDM (HFEDM) and ProTaper Next (PTN) rotary instruments in curved root canals by using micro computed tomography (micro CT) imaging. MATERIALS AND METHODS A total of 22 mandibular molar teeth having separate mesial canals with 20 to 30deg curvatures were randomly divided into two groups and instrumented with HFEDM (OneFile) or PTN (X1 and X2) Pre and post instrumentation micro CT scans were obtained. Mesiodistal canal transportation and centering ability were evaluated in four cross sections (2, 4, 6, and 8 mm from apex) Changes in canal volume and surface area were measured for a 10 mm standardized area of interest. Kolmogorov Smirnov and Shapiro Wilk tests were used to assess the normality and homogeneity. Independent and paired t tests and one way ANOVA were used to analyze data at the p 0.05 level. RESULTS Compared to PTN, HFEDM showed significantly less mesiodistal canal transportation and improved centering ability in cross section L6 (p 0.05) The instruments showed similar increases in volume and surface area of the canals, with minor insignificant differences. CONCLUSION HFEDM and PTN files were safe to use in curved canals and showed similar shaping ability, while respecting the original anatomies. HFEDM OneFile performed better at the vicinity of the danger zone in terms of mesiodistal canal transportation and centering ability.
The journal of contemporary dental practice