Wiseman, et al.32 (2011) evaluated the efficacy of CH removal with sonic irrigation and ultrasonic irrigation in the mesial root canal of mandibular molars by using the same volume irrigant (6% NaOCl+14% EDTA) and same time interval. Authors found PUI repeated 3 times with 20 sec. intervals was more effective than sonic irrigation. This study’s results are similar to the findings of Wiseman, et al.32 (2011), who found PUI was superior to sonic irrigation, although a different duration and irrigation regime was applied.