International Arab Journal of Dentistry


The aim of this in vitro study was to evaluate the efficacy of passive ultrasonic irrigation used as adjunct during endodontic retreatment and its effect on the removal of obturation material from canal walls.Thirty-six extracted human single-rooted teeth were instrumented and obturated with gutta-percha and zinc oxide-eugenol- based sealer using the lateral condensation technique. Teeth were stored at 37ºC in a humid environment for four weeks. The removal of root canal filling was performed using ProTaper™ universal retreatment rotary files without solvent. Teeth were then divided into three groups of 12 specimens each based on the irrigation technique: group 1) syringe irrigation technique with 5.25% NaOCl solution applied as a final irrigation; group 2) passive ultrasonic irrigation technique using # 25 stainless steel files and ultrasonic activation for one minute; group 3) passive ultrasonic irrigation technique applied three times of one minute each. The teeth were longitudinally split in half and photographed. The amount of residual filling material was evaluated according to Hülsmann’s scoring system. Mann-Whitney U test revealed that the amount of residual filling material in group 3 was significantly lower than those of groups 1 and 2. PUI enhanced the removal of filling material from root canal walls during endodontic retreatment.