The rise of the worldwide dental implant market constantly increases the concerns regarding the quality, efficiency and lifetime of dental implants. Titanium based materials have shown proven ability for application in this field, essentially due to their adequate mechanical properties, corrosion behavior and biocompatibility. However, and despite the high success rates associated with dental implants, failures still continue to occur. Among the problems affecting the performance of dental implants, one can find: lack of osteointegration, propensity for bacterial colonization and corrosion/tribocorrosion processes. All these aspects are highly dependent on the surface properties of the implant. Ideally, implant surfaces should simultaneously promote adhesion of osteoblasts and inhibit the colonization by unwanted microorganisms. Furthermore, it is also necessary to minimize combined actions between corrosion and wear (tribocorrosion) that can cause degradation of the implant surface and ultimately lead to its failure. This thesis presents an approach to develop multifunctional titanium oxide surfaces with excellent tribocorrosion performance, while promoting a bio-selective behavior between the adhesion of osteoblastic cells and the minimization of bacterial colonization. For that purpose, surface modification of titanium by Micro-Arc Oxidation was performed, allowing the formation of a thick, adherent and porous titanium oxide structure with incorporated bioactive elements such as calcium, phosphorous, magnesium and zinc. A detailed characterization of the surfaces provided important insights for the understanding of the mechanisms of film formation. Moreover, the results allowed the correlation between chemical/structural properties of the oxide, and their effect on biological and tribocorrosion mechanisms. The surfaces developed in this work presented excellent tribocorrosion resistance, good interactions with osteoblastic cells, and promising antimicrobial properties. |