Residual Microstrain in Root Dentin after Canal Instrumentation Measured with Digital Moiré Interferometry.

•This study evaluated the residual microstrain in root dentin after canal instrumentation.•Teeth were maintained in hydrated and non- hydrated environments.•The residual microstrain was evaluated using digital moiré interferometry.•The biomechanical response of root dentin to instrumentation was influenced by hydration.•Instrumentation did not increase the residual microstrain in hydrated root dentin.