Evaluation of the antibacterial effect of chitosan, cold atmospheric plasma and sodium hypochlorite on Enterococcus faecalis in mandibular second primary molars: An in vitro study

Background Persistent microbial infection is the primary cause of pulpectomy failure in primary teeth. Enterococcus faecalis is among the most resistant microorganisms associated with endodontic treatment failure. Conventional irrigants, such as sodium hypochlorite, are effective; however, their clinical use is associated with several limitations in pediatric dentistry, prompting the investigation of alternative agents such as chitosan and cold atmospheric plasma (CAP). This study aimed to evaluate and compare the antibacterial effects of chitosan, cold atmospheric plasma, and sodium hypochlorite against Enterococcus faecalis in mandibular second primary molars. Methods In this in vitro study 33 deciduous second molars with at least two-thirds of their root length were prepared by chemomechanical method. Enterococcus faecalis inoculum suspension was inoculated into the canals of each tooth and sampling was done to ensure biofilm formation. For disinfection of the canals, the teeth were divided into 3 groups: sodium hypochlorite, cold atmospheric plasma and chitosan. After applying disinfection methods, secondary sampling of the contents inside the canal was performed and the secondary CFU was counted, and finally the primary and secondary CFU levels were compared. The data were analyzed using one-way ANOVA statistical test, considering α = 0.05. Results The values ​​(mean ± standard deviation) of the primary and secondary CFU logarithms in the sodium hypochlorite (Hypo) group were (7.45 ± 0.08) and (5.89 ± 0.02), respectively, in the chitosan group (Chitosan) were (7.58 ± 0.04) and (5.89 ± 0.03), respectively, and in the cold atmospheric plasma (CAP) group were (7.56 ± 0.05) and (5.9 ± 0.03), respectively. The CFU level in the Hypo group was significantly lower than that of the Chitosan and CAP groups (p = 0.001 and p = 0.003, respectively). However, there was no statistically significant difference between the Chitosan and CAP groups (p = 0.641). Although statistically significant differences were observed among the groups, the mean percentage bacterial reduction did not differ significantly and was not considered clinically relevant. Conclusion There is no clinical difference in the antibacterial activity of chitosan, cold atmospheric plasma, and sodium hypochlorite on Enterococcus faecalis in mandibular second primary molars, These findings suggest that chitosan and cold atmospheric plasma may serve as potential alternatives to sodium hypochlorite for root canal disinfection in primary teeth. Keywords : Chitosan; cold atmospheric plasma; Enterococcus faecalis; sodium hypochlorite; primary teeth.