Background: Persistence of microbes is the main cause for root canal failure. Nanoparticles such as chitosan can prevent reinfection as chemo-mechanical preparation cannot abolish all the microbes. Aim: To investigate the antimicrobial efficacy of chitosan nanoparticles when they were combined with calcium hydroxide (CaOH 2 ) and 2% chlorhexidine digluconate against Enterococcus faecalis and Staphylococcus aureus . Materials and Methods: One hundred and forty single-rooted teeth were collected and root canal treatment was done. E. faecalis and S. aureus ( n = 70 each) were inoculated and incubated for 21 days at 37°C. The teeth were then divided into seven experimental groups ( n = 10 each) negative control, positive control, Ca (OH) 2 , chlorhexidine digluconate (2%), chitosan nanoparticles, Ca (OH) 2 plus chitosan nanoparticles, and chlorhexidine digluconate (2%) plus chitosan nanoparticles. The above-mentioned intracanal medicaments were then placed and incubated at 37°C for 7 days. Colony-forming units (CFUs) were estimated using the standard loop method. Scanning electron microscope was used to confirm the microbial penetration and distribution. Analysis of data was dealt with the one-way ANOVA ( P < 0.05) and pairwise comparison was done by Tukey’s post hoc procedure. Results: Chitosan nanoparticles samples exhibited fewer CFUs of all the experimental groups and Ca (OH) 2 exhibited highest number. Conclusion: All the four medicaments showed significant reduction in the bacterial count. Chitosan nanoparticles exhibited greatest antimicrobial efficacy against E. faecalis and S. aureus than other experimental groups.
Nallamilli et al. (Mon,) studied this question.