The aim of root canal irrigation is to clean out the root canal as much as possible. Root canal contains pulp tissues, microorganisms and smear layers. It's impossible to completely remove all these stuff from root canal because of root canal anatomy. If you use calcium hydroxide as interappointment medication, it might act as a contaminants in the root canal. Conventional needle irrigation has limitations in cleaning the root canal. Ultrasonic devices can help you with this irrigation by increasing the efficiency. You can save time, and maybe, they will increase a success rate of your root canal treatment.