Effects of Endodontic Sealers and Irrigation Systems on Smear Layer Removal after Post Space Preparation.

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 (α = 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.