Evaluation of antibacterial efficacy and surface roughness of orthodontic brackets coated with silver–copper hybrid or zinc oxide nanoparticles: An in-vitro study

BACKGROUND/OBJECTIVES: Throughout the course of orthodontic treatment, preventive measures are crucial to lower the risk of plaque accumulation, subsequent decalcification, and the development of white-spot lesions. This study was done to assess antibacterial efficacy of orthodontic brackets covered with nanoparticles mixture with silver–copper oxide or zincoxide. METHODOLOGY: This in-vitro study includes three groups of 12 brackets each coated with coated with nanoparticles combined with silver–copper oxide hybrid or zincoxide, and an uncoated group as the control. Physical vapor deposition was used for the coating process. Using the colony-forming unit, the antibacterial efficacy was assessed against Lactobacillus acidophilus and Streptococcus mutans. The antibacterial activity of coated brackets was assessed at just after coating and four months later. The obtained data were statistically evaluated. RESULT: The L.acidophilus and S. mutans count was reduced most effectively by brackets coated with a blend of silver and copper oxide nanoparticles, followed by zinc oxide nanoparticles, and least effectively by control groups. When compared to an unprotected surface, the surface is smoothed out after being covered with nanoparticles. CONCLUSION: The strongest antibacterial activity was found in brackets coated with silver–copper oxide hybrid followed by zinc oxide nanoparticle combination and least with uncoated brackets. In order to prevent decalcification, orthodontic bracket antibacterial coating could be further evaluated in clinical settings.