Antimicrobial efficacy of chitosan nanoparticles as intracanal medicament against Enterococcus faecalis and Staphylococcus aureus: An in vitro study

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 (Ca[OH] 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.