Int Orthod. 2026 Jul 27;24(4):101217. doi: 10.1016/j.ortho.2026.101217. Online ahead of print.
ABSTRACT
OBJECTIVE: To compare the surface morphology and time-dependent antimicrobial effectiveness of antibiotic-loaded silver and gold nanoparticle coatings, with or without polyethylene glycol, applied to anodized titanium orthodontic mini-implants.
METHODS: Twenty-eight Ti-6Al-4V mini-implants (ARROW) were divided into four groups: Ti-AgNP-PEG-CM (Group A), Ti-AgNP-CM (Group B), Ti-AuNP-PEG-CM (Group C), and Ti-AuNP-CM (Group D). After anodization and SILAR nanoparticle deposition, the surface morphology was examined by HR-SEM and atomic force microscopy (AFM), the chemical composition was analysed by Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR), and crystallographic phase characterisation was performed by X-ray diffraction (XRD). Antibacterial activity against Staphylococcus aureus and Enterococcus faecalis was quantitatively evaluated at 6, 24, 48, and 72hours using a standard colony-forming unit (CFU/mL) assay. A two-way repeated-measures ANOVA with Bonferroni correction was used for statistical analysis.
RESULTS: PEG-containing groups demonstrated lower surface roughness on AFM and more homogeneous surface morphology on SEM. XRD suggest crystalline fcc nanoparticle deposition in respective groups. ATR-FTIR spectra showed characteristic bands attributable to PEG (1070-1110cm-1) and clindamycin-related functional groups (600-3400cm-1) across the coated groups. Group C achieved the lowest average colony counts for both S. aureus. Coating over time showed a significant interaction (P<0.001).
CONCLUSIONS: Ti-AuNP-PEG-CM demonstrated the most effective antibacterial performance against both test organisms throughout the 72-hour evaluation period. Although direct drug-release kinetics were not measured in this study, PEG emerged as an important formulation factor across nanoparticle types. These findings support further in vivo evaluation of PEG-based nanocomposite coatings to reduce early peri-implant bacterial colonization.
PMID:42508092 | DOI:10.1016/j.ortho.2026.101217
