Combating Enterococcus faecalis and Candida albicans: The role of chitosan nanoparticle in intracanal therapy – An in vitro microbiological study

Abstract Context: Persistent endodontic infections caused by Enterococcus faecalis and Candida albicans often resist standard intracanal medicaments. Chitosan nanoparticles (CNPs), with their antimicrobial and drug-delivery potential, may improve disinfection efficacy. Aims: To evaluate and compare the antimicrobial efficacy of calcium hydroxide and chlorhexidine intracanal medicaments, with and without chitosan nanoparticle incorporation, against E. faecalis and C. albicans at different time intervals. Setting and Design: In vitro microbiological study. Materials and Methods: An eighty in vitro agar well-diffusion model was used to assess the antimicrobial efficacy of four formulations – calcium hydroxide (Ca[OH] 2 ), Ca (OH) 2 + CNPs, 2% chlorhexidine (CHX), and CHX + CNPs against E. faecalis and C. albicans at 3- and 7-day intervals. Statistical Analysis Used: Data were statistically analyzed using the one-way analysis of variance and Tukey’s post hoc test ( P < 0.05). Results: CNP incorporation significantly enhanced and prolonged antimicrobial activity. CHX + CNPs showed the largest inhibition zones (28.0 ± 1.9 mm vs. C. albicans , P = 0.042), while Ca (OH) 2 + CNPs exhibited a time-dependent increase (0 → 23.0 ± 2.1 mm vs. E. faecalis , P = 0.003). Conclusion: CNPs synergistically potentiate conventional medicaments via deeper diffusion, sustained release, and intrinsic antimicrobial action.