A Stereomicroscopic Evaluation of Root Dentin Defects Caused by Hand Files and Different NiTirotary Instruments - An In Vitro Study

To compare dentinal cracks caused by hand and rotary nickel titanium instruments using Hyflex ,Pro Taper and K3 sysrems after root canal preparation. Methodology: Eighty mandibular premolarswith single canalwere randomly divided into 4 groups and were mounted in acrylic tubes with simulated periodontal ligaments and the apex was exposed. The root canals were instrumented with different rotary files, namely (Protaper files, Hyflex CM files, K3 files) and K files short of apex. All specimens were kept moist throughout the procedure to prevent dehydration. All roots will be cut longitudinally in two halves and sections will be seen under stereomicroscope. Appearance of dentinal damage will be registered by pictures that will be taken digitally.All the data was statistically analyzed using one way chi square test. Conclusion: Hyflex CM rotary files caused more dentinal cracks thanprotaper and K3 Files. hand files caused least dentinal cracks.