Effects of UV-exposure of titanium-based dental implant materials

Abstract

This work has been carried out as a collaboration between Chalmers University of Technology and Nobel Biocare. The aim of this master thesis was to evaluate the photocatalytic activity and hydrophilic roperties of different titanium surfaces when they were exposed to UV radiation. It was also of interest to investigate the in uence of storing the materials in different media; air, ethanol and plastic bags. Further it has been explored if a custombuilt UV activation device built with LED lamps would be comparable to a commercially available UV lamp. Materials included in this study are machined titanium discs, titanium dioxide discs and TiUnite discs. The techniques that were used to evaluate the photocatalytic effect were degradation of methylene blue, contact angle measurement, and x-ray photoelectron spectroscopy, XPS. It can be concluded that the photocatalytic effect could be activated for both the TiUnite and TiO2 discs by exposing them to UV radiation. The machined surface showed a small photocatalytic effect that could only be observed in the experiments of degradation of methylene blue. Storage of the different discs in air and plastic increase the contact angle, where as storage in EtOH decrease the contact angle instead. The largest contact angle was observed when the discs were stored in plastic bags. The amount of carbon increased with storage time, on the TiUnite discs and the TiO2 discs, however these carbons could be removed by exposing the discs to UV light. The use of UV radiation to activate the photocatalytic activity of TiUnite and TiO2 surfaces was shown to be successful when the contact angle decreased and the methylene blue degraded in some cases after exposure. Exposing these surfaces to UV radiation could give rise to materials with improved properties, used in dental applications, that could potentially increase the success rate of dental implants.