An Evaluation of the Effect of Pulsed Ultrasound on the Cleaning Efficacy of Passive Ultrasonic Irrigation

PUI with a pulsation pattern of 400 milliseconds on/400 milliseconds off and a duty cycle of 50% is more effective in removing dentin debris from a simulated apical oval extension in standardized root canals than continuous ultrasonic activation. Duty cycles of 13% and 88% showed no difference compared with continuous oscillation.