Comparative evaluation of efficacy of ethylenediaminetetraacetic acid, maleic acid, and dimercaptosuccinic acid against the combination of these with sodium hypochlorite for removal of smear layer: An in vitro scanning electron microscope study

CONTEXT: The effect of dimercaptosuccinic acid (DMSA) and maleic acid (MA) when used alone on smear layer has been evaluated with mixed results, but their effect when combined with sodium hypochlorite (NaOCl) has not been studied. AIM: To compare the effectiveness of ethylenediaminetetraacetic acid, MA, and DMSA against the combination of these with NaOCl in the removal of smear layer. SETTINGS AND DESIGN: n = 4pq/L(2) q = 1 − p p = Incident rate L = Allowable error METHODS: One hundred and forty extracted, anterior teeth were radiovisiographically assessed. Access preparation was done; apical patency was established. Cleaning and shaping was accomplished using step-back technique. The specimens were randomly allocated as per the final irrigation protocol. After final irrigation, teeth were prepared for scanning electron microscope analysis, and the middle and apical thirds of radicular dentin were evaluated at ×1000 for evaluation of severity of occlusion of dentinal tubules with smear layer. STATISTICAL ANALYSIS: The data were statistically analyzed using the Student's t-test and kappa test. RESULTS: For combined irrigation, 10% DMSA + NaOCl was significantly better than all other groups both in the middle third and the apical third. It was more effective in the middle third than at apical third. CONCLUSION: Ten percent DMSA in combination with NaOCl removes the smear layer more effectively at both the middle and apical third.