Effects of surface treatments on the fatigue resistance of biocompatible metals

Metal implants are relatively effective but they still need significant improvements with respect to their capacity to secure rapid and long-lasting integration in tissues. To address these challenges, different strategies have been developed to directly affect the cellular events at the material-host tissue interface. Chemical treatments such as oxidative nanopatterning and anodization are very effective tools to endow medically relevant metals (in particular titanium and Ti6Al4V) with the ability to stimulate and guide cellular events. This remarkable capacity results from the creation of distinctive nanoporous surfaces. To date, only few studies focused on mechanical aspects to ensure that such chemical approaches do not weaken mechanical properties of treated metals. Nanoporous structures could in fact act as surface defects and/or stress-raisers responsible for initiating crack nucleation and lead to premature failure. To elucidate this aspect, we have assessed the effects of oxidative nanopatterning and anodization on the fatigue resistance of pure titanium and Ti6Al4V. In particular, we aimed at investigating the fatigue performance from both quantitative (i.e. S-N curves) and qualitative (i.e. morphological SEM analysis) perspectives. Results from our study highlight the importance of mechanical considerations in the development and evaluation of nanoscale surface treatments for metallic implants. (Read more)

Project in collaboration with Dr. A. Weck (uOttawa)

Titania nanotubes created on grade 2 titanium by anodization

© 2013 by Fabio Variola. All rights reserved