The influence of blasting and sterilization on static and time-related wettability and surface-energy properties of titanium surfaces

Different studies have been focused on the interaction between the synthetic material/biological entities. Nevertheless it is not still understood how the different surfaces properties influence the biological response of the implants due to the lack of a thorough characterization. The aim of this work is to thoroughly characterize topographically and energetically the sterilized and polished or blasted titanium surfaces in order to elucidate, in further studies, their influence in surface/protein interactions. The ultimate goal is to define surface characteristics that optimize the biologic responses of implants. Focusing on the first events that occur when introducing an implant material, commercially pure Ti grit-blasted samples with different roughness and different sterilization procedures have been characterized in terms of the dynamic of surface wetting with water and different biological medium. Moreover, a complete and reliable characterization of roughness, wettability, chemical surface composition and surface energy of those materials has been done. The nature of the abrasive particles and the sterilization procedures are the main factors affecting the surface energy and the wettability of polished and blasted titanium surfaces. Steam autoclaving and ethylene oxide increase surface hydrophobicity, consequently the base-Lewis component of the surface energy is altered. Time-related contact angle results indicate that proteins adsorb on titanium surfaces and make them significantly more hydrophilic. Those results provide new insights into the complex relationships between the different parameters of titanium surfaces that govern their surface energy and their wettability behaviour.