Comparison of smear layer removal with the use of chitosan oligosaccharide, citric acid, and ethylenediaminetetraacetic acid in root canals of human lower pre-molars: Scanning electron microscope study

Purpose: The purpose of this study was to compare the efficacy of chitosan (CS)-derivative and its bind-ing to citric-acid with chelators traditionally used in clinical practice.
Methods: 50 lower pre-molars were decoronated, standardizing a length of 15 mm, subsequently were instrumented with telescopic technique up to diameter 40.02, irrigated with 5% sodium hypochlorite. The samples were divided according to the treatment of smear layer (SL) (n = 10). Group I: 5% CS-oligo-saccharide, Group II: 5% CS-oligosaccharide citrate, Group III: 10% citric acid, Group IV: 17% ethylenedi-aminetetraacetic-acid (EDTA), and Group V: distilled water. The samples were sectioned longitudinally, sputtered with gold, and observed with scanning electron microscope (SEM) under ×2000 and ×5000 magnifications. Data were analyzed using Kruskall-Wallis test followed by Mann-Whitney U test.
Results: In the apical third, CS-oligosaccharide citrate demonstrated better SL removal compared to the other groups (p < 0.05) but not with EDTA (p > 0.05). In the cervical and middle thirds, no differences were found (p > 0.05).
Conclusion: CS-oligosaccharide and CS-oligosaccharide citrate demonstrated similar chelating effect to citric acid and EDTA but were not superior.