LAUSR

Introduction: The aim of this study was to investigate the effects of endodontic sealer types and ultrasound on smear layer removal after post space preparation. Methods: Thirty‐six bovine incisors were chemomechanically instrumented and randomly divided into 3 groups (n = 12) according to the endodontic sealer (AH Plus [Dentsply DeTrey, Konstanz, Germany], Apexit Plus [Ivoclar Vivadent AG, Schaan, Fürstentum Liechtenstein], or iRoot SP [Innovative Bioceramix, Vancouver, BC, Canada]) used during root canal obturation, and the groups were further subdivided randomly into 3 subgroups (n = 4) based on the post dowel irrigation systems (ultrasound, regular rinse, or control) used. The samples were examined under a scanning electron microscope and were scored for debris and tubule openings using a 3‐scale grading system. The Friedman test, Wilcoxon signed rank test, Kruskal‐Wallis analysis, and Mann‐Whitney U test were used to statistically analyze the results (&agr; = 0.05). Results: Samples in the AH Plus group were more easily debrided than those in the iRoot SP group (P < .05). The best tubule opening condition was presented in samples in the AH Plus group, whereas those in the iRoot SP group presented the worst (P < .05). The regular rinse and ultrasonic groups were similarly good at smear layer removal and tubule opening (P > .05) compared with the control group (P < .05). The samples using AH Plus in combination with ultrasound or syringe rinsing showed the best cleaning result among all of the subgroups (P < .05). Conclusions: AH Plus presented the easiest removal from the post space, whereas iRoot SP presented the most difficult removal. Ultrasound improved the cleaning efficacy of post dowels as did the regular rinse. HIGHLIGHTSWe were the first to appraise the effect of iRoot SP on post space smear layer removal.We compared the efficacy of different post dowel irrigation procedures.AH Plus was the easiest to be removed from the post space.iRoot SP could not be effectively removed no matter how the post space was irrigated.Ultrasonic irrigation provided the same level of cleaning efficacy as syringe rinsing did.