Sonic and Ultrasonic Enhancement of Chitosan Nanoparticle Activity Against IntracanalBacteria: An In Vitro Study

Introduction: To compare the antimicrobial efficacy of CNPs with NaOCl, CHX, and EDTA when activated using sonic or ultrasonic techniques. Material and Methods: Sixty extracted single-rooted human teeth were prepared and inoculated with E. faecalis biofilms for 21 days. The samples were randomly assigned to six groups: I – NaOCl + sonic activation, II – CHX + sonic activation, III – EDTA + sonic activation, IV – CNP + sonic activation, V – CNP + ultrasonic activation, VI – saline + sonic activation (control). Microbial samples were collected before and after irrigation, and bacterial viability was assessed by colony-forming unit (CFU) counts. Results: All experimental groups significantly reduced CFUs compared to control (p < 0.05). NaOCl exhibited the greatest antibacterial effect, followed by CNP with ultrasonic activation. CNP with sonic activation demonstrated greater efficacy than EDTA and comparable performance to CHX. Ultrasonic activation enhanced the antimicrobial effect of CNPs compared to sonic activation. Conclusion: CNPs showed substantial antibacterial activity against E. faecalis, particularly when combined with ultrasonic activation. These results indicate that CNPs could serve as a safe and effective alternative to traditional irrigants, though further clinical studies are needed to confirm their in vivo performance.