Phosphorus-and-Silver-Doped Crystalline Oxide Coatings for Titanium Implant Surfaces

Abstract

Bacteria-related infections remain a leading cause of dental implant failures. Despite the successful history of titanium implants, naturally forming oxides lack antibacterial properties. Crystalline oxides, modified through anodization processes, have shown photocatalytic-induced antibacterial properties when exposed to sufficient energy sources such as UVA light. Chemically doping these oxides with some metallic and non-metallic elements has been shown to enhance their photocatalytic activity (PCA). The present study’s objectives were to assess the relative UVA and violet-light-irradiated PCA levels, bacterial attachment levels, and pre-osteoblast early cell viability levels of phosphorus-doped and phosphorus-and-silver-doped anatase-phase oxides. Each oxide revealed similar surface topographies and surface porosity levels. However, the phosphorus-and-silver-doped oxides exhibited significantly higher PCA levels compared to the phosphorus-doped oxide counterpart after irradiation with 365 nm UVA (p < 0.0001) or 410 nm violet (p = 0.007 and 0.03) light. The phosphorus-doped oxides and phosphorus-and-silver-doped oxides revealed similar Staphylococcus aureus attachment levels after 60 min of UVA irradiation. The phosphorus-and-silver-doped oxides exhibited significantly increased 7-day cell viability compared to their phosphorus-doped oxide counterparts. Thus, it was concluded that the silver doping additions to the oxides show much promise for biomaterials applications and warrant further exploration.