Effectiveness of Final Irrigant Protocols for Debris Removal from Simulated Canal Irregularities

•An association was observed among the debris scores and protocols that used passive ultrasonic irrigation (PUI).•In groups that used PUI, the frequency of scores 1 and 2 was higher than expected.•The frequency of score 4 was lower than expected in groups that used PUI.•No association was found among the scores of debris removal and the irrigants.

IntroductionThe aim of this in vitro study was to compare the effectiveness of saline, 2.5% sodium hypochlorite, and 2% chlorhexidine, with or without passive ultrasonic irrigation (PUI), in debris removal from simulated canal irregularities within prepared root canals.MethodsNinety bovine lateral incisors were randomly divided into 3 main groups (n = 30) based on the irrigant and prepared with hand files attached to an oscillating handpiece (NSK, Tokyo, Japan) up to a size #80 K-file. Next, the teeth were split longitudinally, and a standardized groove was prepared into the apical third and filled with dentin debris. After the halves were reassembled, they were placed in a muffle. Each main group was randomly subdivided into 2 groups (n = 14) and was treated with different final irrigation protocols. In the sodium hypochlorite/PUI, chlorhexidine/PUI, and saline/PUI groups, the solution was ultrasonically activated 3 times for 20 seconds. In the remaining groups, PUI was not performed. Specimens were scored for debris removal and analyzed under a scanning electron microscope.ResultsAn association was observed between the score of debris removal and protocols using PUI (P < .05). No association was observed between the scores of debris removal and the irrigants (P = .87).ConclusionsFinal irrigation protocols that used PUI were more effective in removing debris from simulated canal irregularities into the apical third than those that did not use it.