Led Replace Mercury Lamps For Ultraviolet Photofunctionalization On Titanium Surface

to compare the effectiveness of photofunctionalization technologies on titanium surface by using two different UVC light sources, mercury vapor (Hg-vapor, λ=254 nm) and light-emitting diode (LED, λ=275 nm) radiators By exposing sandblasted and acid-etched titanium discs aged for 4 weeks to two UV light sources with multiple radiant energy, the effect on osseointegration and bacteria and the relevant mechanism was investigated. Results revealed that irradiation on aged titanium surface decreased carbon atom concentration, changed surface from hydrophobic to hydrophilic, consumed oxygen, formed radicals, and altered surface potential. Moreover, compared with the aged titanium disc control group, irradiated groups had enhanced protein adsorption, changed protein structure, promoted in vitro biomineralization, and significantly enhanced human bone marrow mesenchymal stem cell functions. Also, in rat maxillae, irradiated groups had higher bone volume/tissue volume (BV/TV) and bone-implant contact (BIC) after 4 - week healing. In addition, UV-irradiated titanium surfaces inhibited facultative anaerobes such as Staphylococcus aureus and Escherichia coli but promoted anaerobes such as Porphyromonas gingivalis. It is worth noting that the surface carbon, hydrophilicity, protein adsorption, and cell and bacterial attachment all changed in a radiation energy-dependent manner, and UVC-LED radiator showed similar photofunctionalization results as Hg-vapor radiator at similar radiation energies. Therefore, combined with its no mercury, compact design, faster start-up time, and stable output, UVC-LED light source has the potential to be an alternative source of Hg-vapor for UV-photofunctionalization procedure.