To demonstrate that titanium implant surfaces as little as 4 weeks from production are contaminated by atmospheric hydrocarbons. This phenomenon, also known as biological ageing can be reversed by UVC irradiation technically known as photofunctionalization. To propose a new model from our experimental evidence to explain how the changes in chemical structure of the surface will affect the adsorption of amino acids on the titanium surface enhancing osteointegration. In our study XPS and AES were used to analyze the effects of UVC irradiation (photofunctionalization) in reversing biological ageing of titanium. SEM was used to analyze any possible effects on the topography of the surface. UVC irradiation was able to reverse biological ageing of titanium by greatly reducing the amount of carbon contamination present on the implant surface by up to 4 times, while the topography of the surface was not affected. UVC photon energy reduces surface H₂O and increases TiOH with many –OH groups being produced. These groups explain the super-hydrophilic effect from photofunctionalization when these groups come into contact with water. Photofunctionalization has proven to be a valid method to reduce the amount of hydrocarbon contamination on titanium dental implants and improve biological results. The chemisorption mechanisms of amino acids, in our study, are dictated by the chemical structure and electric state present on the surface, but only in the presence of an also favourable geometrical composition at the atomical level.

We present an X-ray absorption spectroscopy study on Fe-doped SrTiO₃ thin films grown by pulsed laser deposition. The Fe L_2,3 edge spectra are recorded for doping concentrations from 0–5% after several annealing steps at moderate temperatures. The Fe valence state is determined by comparison with an ilmenite reference sample and calculations according to the charge transfer multiplet model. We found clear evidence of Fe²⁺ and Fe³⁺ oxidation states independently of the doping concentration. The Fe²⁺ signal is enhanced at the surface and increases after annealing. The Fe²⁺ configuration is in contrast to the mixed Fe³⁺/Fe⁴⁺ valence state in bulk material and must be explained by the specific defect structure of the thin films due to the kinetically limited growth which induces a high concentration of oxygen vacancies.