Evaluating antibacterial efficiency of orthodontic brackets coated with copper oxide, titanium dioxide and silver...

Orthodontic brackets create biofilm niches that promote enamel demineralization and white spot lesions, necessitating effective antibacterial coatings during fixed appliance therapy. Therefore, it is of interest to compare antibacterial activity against Streptococcus mutans and Lactobacillus acidophilus on 80 brackets coated with CuO-NPs, TiO₂-NPs or Ag-NPs versus uncoated controls (n=20/group) using sol-gel dip-coating. All nanoparticle coatings significantly outperformed controls (p<0.001); Ag-NPs showed superior reduction (94.2% S. mutans, 91.8% L. acidophilus), followed by CuO-NPs (87.6%/68.9%) and TiO₂-NPs (72.4%/68.9%). SEM/EDX confirmed uniform nanoparticle deposition on bracket surfaces. Thus, Ag-NP coating is the optimal strategy to minimize orthodontic biofilm formation and the risk of demineralization, advancing preventive orthodontics through targeted surface modification.