Introduction: Instrumentation may induce dentinal microcracks—precursors to vertical root fracture. Aim: To compare microcrack formation using ProTaper Universal, Twisted File Adaptive, and Blue NiTi EndoArch via micro-CT. Methods: 45 extracted mandibular molars decoronated, randomized to three instrument systems. Pre- and post-instrumentation micro-CT at 14 μm; blinded evaluation of coronal, middle and apical thirds. Results: Rotary instruments produced more microcracks than the adaptive motion system. Conclusion: Adaptive motion systems may reduce iatrogenic dentinal microcracks compared to conventional rotary systems.
Bodkhe et al. (Sun,) studied this question.