| White spot lesions (WSLs) are one of the adverse effects of fixed orthodontic treatments. They are the primary sign of caries,
which means inhibiting this process by antibacterial agents will reverse the procedure. The current study tested the surface
modification of nickel-titanium (NiTi) wires with ZnO nanoparticles (NPs), as antimicrobial agents. As the morphology of
NPs is one of the most critical factors for their properties, the antibacterial properties of different morphologies of ZnO
nanostructures coated on the NiTi wire were investigated. For the preparation of ZnO nanostructures, five coating methods,
including chemical vapor deposition (CVD), chemical precipitation method, polymer composite coating, sol-gel synthesis, and
electrospinning process, were used. The antibacterial activity of NPs was assessed against Streptococcus mutans by the colony
counting method. The obtained results showed that all the samples had antibacterial effects. The antibacterial properties of
ZnO NPs were significantly improved when the specific surface area of particles increased, by the ZnO nanocrystals prepared
via the CVD coating method. |