Construction of a TiO₂/MoSe₂/CHI coating on dental implants for combating Streptococcus mutans infection

Infection and inflammation are the main causes resulting in the failure of dental implants. In this work, molybdenum diselenide (MoSe₂) was synthesized hydrothermally on the surface of porous TiO₂ coating prepared by micro-arc oxidation on titanium (Ti) implants to render the coating excellent in situ antibacterial activity under the irradiation of near-infrared (NIR) light. Chitosan (CHI) was adsorbed on the surface of MoSe₂ nanosheets by electrostatic bonding to improve the biocompatibility. The introduction of MoSe₂ significantly improved the photothermal and photodynamic ability of TiO₂ coating and made the implants possess excellent in vitro and in vivo antibacterial property against Streptococcus mutans (S. mutans) under the irradiation of 808 nm NIR light for 15 min because of the synergistic of hyperthermia and reactive oxygen species (ROS). The immobilization of CHI improved the hydrophilicity and biocompatibility of MoSe₂, and the hybrid coating (TiO₂/MoSe₂/CHI) promoted osseointegration even in the presence of infection in vivo under 808 nm light irradiation. The light - assisted antibacterial coating described here has large clinical potential in dental implants applications.