assalamualaikum wr wb.. good morning!! ----- ULTRASONIC PROTOCOLS SUBSCRIBE TO http://youtube.com/riosuryantoro ----- After the root canal has been shaped to the master apical file (irrespective of the preparation technique used), an ultrasonic tip is then introduced into the canal filled with irrigant, and this ultrasonic oscillating tip will activate the irrigant. As the root canal has already been shaped, the ultrasonic tip can move freely and the irrigant can penetrate more easily into the apical part of the root canal system. Irrigation of the root canal space is a fundamental aspect of root canal treatment. Techniques for acoustic and hydrodynamic activation of the irrigant have been developed, because syringe irrigation is not effective in the apical part of the root canal. It has been shown that acoustic streaming and cavitation contribute to the cleaning efficiency of root canal irrigation. Acoustic streaming can be defined as a rapid movement of fluid in a circular or vortex-like motion around a vibrating file. Cavitation can be defined as the creation of vapor bubbles or the expansion, contraction, and/or distortion of preexisting bubbles (so-called cavitation nuclei) in a liquid; the process is coupled to acoustic energy. ..... Jiang Lei Meng, Verhaagen Bram, Versluis Michele, Lucas W M. Evaluation of sonic device to activate Irrigate In the Root Canal. JoE. 2009. ..... thanks for watching! SUBSCRIBE TO http://youtube.com/riosuryantoro to get the latest notificatons ----- regards, Rio Suryantoro, drg., SpKG (endodontist / conservative dentistry enthusiast from Jakarta-Indonesia)