Comparative evaluation of dentinal crack formation after root canal preparation using ProTaper Next, OneShape, and Hyflex EDM.

Introduction: The purpose of this study was to compare the incidence of dentinal crack formation after root canal preparation using ProTaper Next, OneShape, and Hyflex electrodischarge machining (HEDM).
Materials and Methods: A total of 75 extracted mandibular premolars were selected. The root canals were instrumented using ProTaper Next, OneShape, and HEDM rotary files. All roots were horizontally sectioned at 3, 6, and 9 mm from apex with slow-speed saw under water cooling. The sections were observed under a stereomicroscope at ×25 to determine the absence or presence of crack. Data were analyzed using post hoc test and one-way ANOVA.
Results: ProTaper Next and HEDM produced significantly less cracks than OneShape.
Conclusion: Within the limitation of this in vitro study, it can be concluded that nickel-titanium instruments may cause cracks on the root surface. ProTaper Next and HEDM tend to produce less number of cracks as compared to OneShape.
Competing Interests: There are no conflicts of interest.