Fabrication of Bioactive, Antibacterial TiO₂ Nanotube Surfaces, Coated with Magnetron Sputtered Ag Nanostructures for Dental Applications

We investigated whether a silver coating on an anodic oxidized titania (TiO₂) nanotube surface would be useful for preventing infections in dental implants. We used a magnetron sputtering process to deposit Ag nanoparticles onto a TiO₂ surface. We studied different sputtering input power densities and maintained other parameters constant. We used scanning electron microscopy, X-ray diffraction, and contact angle measurements to characterize the coated surfaces. Staphylococcus aureus was used to evaluate antibacterial activity. The X-ray diffraction analysis showed peaks that corresponded to metallic Ag, Ti, O, and biocompatible anatase phase TiO₂ on the examined surfaces. The contact angles of the Ag nanoparticle-loaded surfaces were significantly lower at 2.5 W/cm² input power under pulsed direct current mode compared to commercial, untreated Ti surfaces. In vitro antibacterial analysis indicated that a significantly reduced number of S. aureus were detected on an Ag nanoparticle-loaded TiO₂ nanotube surface compared to control untreated surfaces. No cytotoxicity was noted, except in the group treated with 5 W/cm² input power density, which was the highest input of power density we tested for the magnetron sputtering process. Overall, we concluded that it was feasible to create antibacterial Ag nanoparticle-loaded titanium nanotube surfaces with magnetron sputtering.