Effects of chitosan oligosaccharide and calcium hypochlorite on dentinal biofilm and smear layer removal - SEM analysis.

Background: The complex structure and irregularities of root canal walls are liable for infection by several bacterial species. Thus, the use of irrigants and auxiliary chemical solutions associated with instrumentation is necessary for effective eradication of the biofilm as well as complete removal of the smear layer.

Aim: To evaluate the effects of calcium hypochlorite and chitosan oligosaccharide (COS) in disinfecting Enterococcus faecalis root canal biofilm and smear layer removal with minimal erosion.

Materials And Methods: A total of 70 mandibular premolars were decoronated at the cementoenamel junction. The samples were biomechanically prepared, sterilized in an autoclave, and incubated with E. faecalis (ATCC-29212) bacteria for 21 days. Cleaning and shaping were done till maximum apical file size of #45 K. Specimens were randomly divided into 4 groups: GROUP I: Control Group, GROUP II: 5% Sodium Hypochlorite (NaOCl) solution followed by 17% EDTA solution, GROUP III: 5% Calcium Hypochlorite [Ca(OCl)] solution followed by 17% EDTA solution and GROUP IV: 5% Ca(OCl) solution followed by 1% COS. The samples were subjected to microbial count followed by smear layer removal under scanning electron microscope (SEM) at coronal, middle and apical third.

Statistical Analysis Used: Kruskal-Wallis Test and post-hoc Scheffe's test.

Results: It was observed that Group IV showed the lowest amount of CFU count/mL and the highest amount of smear layer removal with a statistically significant difference (P < 0.05) when compared with the other three Groups.

Conclusion: 5% Ca(OCl) solution with 1% COS solution effectively removed the Enterococcus faecalis biofilm and smear layer from the root canals with minimal erosion.