Effect of 5% Carbohydrate Derived-Fulvic Acid on Smear Layer Removal and Root Dentin Microhardness - An In Vitro study

Objective: To compare the ability of 5% carbohydrate derived-fulvic acid (CHD-FA) with 17% ethylenediamine tetraaceticacid (EDTA) on smear layer removal when used as a final irrigant, and to assess their effect on root dentin microhardness. Methods: A total of 56 single-rooted human mandibular premolars were decoronated to obtain standardized root length of 12 mm. Canal patency was established using 10 size K-file, working length was determined. Based on the irrigation regimen, samples were assigned into three groups; 17% EDTA, 5% CHD-FA and distilled water (control). The canals were instrumented with Protaper till F3 size. A standardized volume of 5 mL of each testing solution was used for 1 min. Roots were longitudinally split into two halves with one half of the samples for SEM analysis to evaluate the smear layer removal at coronal, middle, and apical thirds of root dentin. The other halves of the samples were subjected to Vickers microhardness testing. The data was statistically analyzed using Kruskal Wallis and Post Hoc test (P<0.05). Results: 5% CHD-FA and 17% EDTA showed significant smear layer removal at all levels compared to distilled water (P<0.05). In the apical third, 5% CHD-FA showed significantly increased smear layer removal than EDTA (P<0.05). Microhardness testing of apical third showed significantly lesser reduction in microhardness for CHD-FA than EDTA (P<0.05). Conclusion: 5% CHD-FA could be a promising final irrigant for smear layer removal with decreased microhardness reduction on root dentin compared to 17% EDTA.