Fluorine-Doped ZnO Nanoparticles: Structural Insights and Antibacterial Innovation in Orthodontic Resins

Objectives: This study aimed to develop a bioactive orthodontic composite resin incorporating fluorine-doped zinc oxide (F-ZnO) nanoparticles and to evaluate its mechanical, cytotoxic, biocompatibility and antimicrobial properties. Method: F-ZnO nanoparticles were synthesized using a chemical solution method and characterized through X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM). The nanoparticles were integrated into composite resins and evaluated for antimicrobial efficacy against S. mutans, mechanical strength, and cytotoxicity. Antibacterial activity was assessed using a zone of inhibition assay, while shear bond strength and biocompatibility were also analyzed. Findings: Composite resins containing F-ZnO nanoparticles exhibited significantly enhanced antibacterial properties compared to control resins (P < 0.05), with the inhibition zone reaching up to 10.0 ± 0.31 mm at higher nanoparticle concentrations. Structural characterization confirmed the successful doping of fluorine into ZnO, contributing to improved surface charge and bioactivity. Novelty: No research has been done on developing a bioactive orthodontic composite resin incorporating fluorine-doped zinc oxide (F-ZnO) nanoparticles in recent times. This novel composite resin shows potential for preventing dental caries during orthodontic treatments, representing a promising advance in biomaterial innovation. Keywords: Dental caries, F-ZnO nanoparticles, Resins, Antibacterial activity, X-ray diffraction