Efficacy of Different Irrigant Activation Systems on Debris and Smear Layer Removal: A Scanning Electron Microscopy Evaluation.

Removal of debris and smear layer from the apical part of the root canal by syringe and needle irrigation alone may be significantly improved by using sonic or ultrasonic activation of the final irrigant. Endosonic activation was less effective in removal of smear layer from the apical part of the canals compared to the other two activation systems.