A Comparative Evaluation of Smear Layer Removal by Using Four Different Irrigation Solutions like Root Canal Irrigants: An In Vitro SEM Study

Background: The present study aimed to evaluate and compare the efficacy of 17% ethylenediaminetetraacetic acid (EDTA), 18% etidronic acid, 10% citric acid, and 7% maleic acid in the removal of smear layer at the apical third of the root canals.Materials and methods: Sixty single-rooted teeth were equally divided into four study groups (n = 15), according to the type of irrigant used (17% EDTA, 18% etidronic acid, 10% citric acid, and 7% maleic acid) to remove the smear layer effectively from apical third of root canal.In each group, respective irrigant was used with 5.25% of sodium hypochlorite during instrumentation.Each study sample was then sectioned longitudinally and removal of smear layer was observed using a scanning electron microscope (SEM) at 2000×.Results: A 7% maleic acid revealed better smear layer removal than all other three groups at apical third.A 10% citric acid was found to be more efficient than EDTA and etidronic acid.The intergroup comparison was performed using Mann-Whitney U test, and there was no significant difference between all the study groups, except maleic acid.Conclusion: The present study compared the effect of various irrigants as an adjunct with 5.25% of sodium hypochlorite for root canal irrigation during and after instrumentation.The use of irrigants aids in the removal of the smear layer from the root canals, thereby increasing the success rate of endodontic therapy.Clinical significance: This study supports the hypothesis that a thorough use of root canal irrigants can efficiently remove the smear layer which is the key for successful root canal treatment.The present study helps in choosing an appropriate irrigant that can ensure complete root canal debridement from all thirds, especially from the apical third of the root canal.