Improvement of the Antimicrobial and Antibiofilm Activity of AH Plus Sealer with Chitosan Nanoparticles and Arginine against Enterococcus faecalis and Candida albicans.

The success of endodontic treatments can be significantly impaired by persistent microbial pathogens, especially <i>Enterococcus</i> <i>faecalis</i> (<i>E</i>. <i>faecalis</i>) and <i>Candida</i> <i>albicans</i> (<i>C</i>. <i>albicans</i>). The aim of this study was to investigate how the incorporation of chitosan nanoparticles (CsNPs) and arginine (Arg) can enhance the antimicrobial and antibiofilm efficacy of AH Plus, a widely used epoxy resin-based root canal sealer. The CsNPs were synthesized by ionotropic gelation and assessed for their size, morphology, chemical structure, and cytotoxicity. The antimicrobial effectiveness of the modified sealers was evaluated against <i>E</i>. <i>faecalis</i> and <i>C</i>. <i>albicans</i> by determining the minimum inhibitory concentration, minimum bactericidal concentration, minimum fungicidal concentration, and agar diffusion method. Additionally, antibiofilm activity was assessed using a microtiter plate assay. Characterization of the CsNPs revealed an average size of 144 ± 12.8 nm by scanning electron microscopy and 182.4 nm by dynamic light scattering with a zeta capacitance of +49.2 mV. CsNPs maintained more than 68% cell viability at 625 μg/mL after 24 and 48 hours. Adding CsNPs and Arg significantly enhanced the impact of AH Plus sealer on antimicrobial and antibiofilm, especially at elevated additive concentrations. This study suggests that AH Plus sealers containing CsNPs and Arg may offer a promising approach to enhance endodontic treatment outcomes by efficiently combating resistant root canal infections.