Evaluation of Anti-Biofilm Property of Zirconium Oxide Nanoparticles on Streptococcus mutans and Enterococcus faecalis: An In Vitro Study

Introduction The prevalence of dental caries and endodontic infections caused by bacteria such as <i>Streptococcus mutans</i> and <i>Enterococcus faecalis</i> poses a significant challenge in root canal treatment. These pathogens exhibit significant resistance to antimicrobial treatments due to their ability to form biofilms, complex microbial communities encased in a self-produced extracellular polymeric substance (EPS). Despite advancements in treatment strategies, the failure rate remains high due to the difficulty in completely eradicating microbial populations within the complex root canal system. The increasing prevalence of antibiotic resistance has driven the need for novel antimicrobial agents and strategies to target biofilms. In this study, we evaluated the potential of zirconium oxide nanoparticles (ZrO₂ NPs) in eradicating biofilms formed by <i>S. mutans</i> and <i>E. faecalis</i>, two key pathogens involved in these infections. Materials and methods ZrO₂ NPs were characterized and evaluated for their antimicrobial properties against <i>E. faecalis</i> and <i>S. mutans</i> biofilms. The nanoparticles were characterized using scanning electron microscopy and energy-dispersive X-ray spectroscopy. Biofilm quantification was performed using a crystal violet staining assay. The minimum biofilm eradication concentrations of ZrO₂ NPs against the bacterial strains were determined. Results ZrO₂ NPs used in our study were found to have zirconium predominantly with no impurities. Also, the average particle size was less than 30 nm with a spherical shape arranged in clusters. These characterizations were performed considering the vital role of these properties in obtaining the desired antibacterial/anti-biofilm properties of nanoparticles. ZrO₂ NPs were capable of eradicating the biofilm formed by both <i>S. mutans</i> and <i>E. faecalis</i> at concentrations greater than 22.8 μg/mL. The results suggest that ZrO₂ NPs could be used as a novel approach for combating biofilm-related infections. Conclusion Our findings suggest that ZrO₂ NPs have the potential to be a promising antibiofilm agent in root canal treatment, offering a new approach to combat these persistent infections. Further research is warranted to explore the full potential of nanomaterials in improving treatment outcomes in endodontic infections.