Enhancing the blood response and antibacterial adhesion of titanium surface through oxygen plasma immersion ion implantation treatment

Titanium (Ti) is a biocompatible alloy widely used in dental implants, thanks to the protective Ti oxide film that forms spontaneously on the surface. Unfortunately, the film is bioinert and prone to the release of metal ions. In a previous study, we applied oxygen plasma immersion ion implantation (O-PIII) treatment to Ti surface to enhance the corrosion resistance and cell response of Ti. In this study, we examined the surface characteristics of the treated alloy, including roughness, hydrophilicity, and chemical composition. We investigated the blood response to the O-PIII-treated Ti surfaces, including the blood-clotting ability and platelet adhesion. We also investigated resistance of the treated alloy to the adhesion of oral bacteria, Streptococcus mutans, in terms of bacterial attachment and morphology. Our results demonstrate that O-PIII treatment did not have a significant effect on surface roughness or hydrophilicity. This treatment resulted in the formation of a Ti oxide film containing mainly TiO₂, Ti₂O₃, and TiO. The presence of surface Ti oxides (particularly TiO₂) positively influenced blood-clotting ability and platelet adhesion as well as resistance to bacterial adhesion. These effects were particularly evident when O-PIII treatment was applied at a higher voltage. Our results demonstrate that the proposed O-PIII treatment promotes blood-clotting and resistance to bacterial adhesion in dental implant applications.