Jerome Chevalier, Ph.D.
University of Lyon, Villeurbanne, France
Dr. Jerome Chevalier is a Full Professor at the National Institute of Applied Sciences, in Lyon (INSA-Lyon), France. He is mainly recognized for his work on ceramics for healthcare applications, especially on zirconia as a biomaterial but also on the development of innovative glass-ceramics and calcium phosphate ceramics for bone substitute applications. His research interests are also related to the mechanical behavior laws of ceramics under different forms. He has been involved in a large number of European projects and has a strong involvement in partnerships with European companies. He has published more than 200 papers, holds 10 patents and has been cited more than 13000 times. Jérôme Chevalier has been member of the ‘Institut Universitaire de France’ (2010-2015) and awarded by the French CNRS with the ‘Innovation Medal’ (2015). Jérôme Chevalier is currently senior editor of the Journal of the European Ceramic Society. He is a fellow of the European Ceramic Society (2017) and a member of the World Academy of Ceramics (2018)
Zirconia exhibits the best mechanical properties of oxide ceramics: this is the consequence of phase transformation toughening, which increases its mechanical resistance compared to other inorganic materials. The high strength and toughness of zirconia is associated with excellent biocompatibility and bone-integration, which makes it an excellent candidate as a structural bio-ceramic. Moreover, zirconia is versatile, with properties depending on alloying elements, composition and phases content. It has been developed and clinically used for hip joint applications, dental restorations and implants, as well as innovative housings for neuro-stimulators.
If the key advantages of zirconia are recognized, zirconia is also the subject of specific attention and controversies among scientists, industrials and clinicians, concerning its long-term stability in-vivo. Due to this propensity to transform, zirconia can also be prone to aging and degradation under some conditions: this has been unfortunately verified in particular cases in vivo with critical consequences in some biomedical fields.
In this talk, we will thus briefly summarize the main interest of phase transformation on the strength of this peculiar material, but also its potential Achilles’ heel in relation to ‘Low-Temperature Degradation’, which stands to a progressive phase transformation of zirconia in presence of water or body fluids. We will then review the clinical outputs of the material for hip joint applications, which led to consider other systems such as alumina-zirconia composites, and for dental applications with a strong development this past decade for implants as an alternative to titanium and translucent dental restorations. Last, we will emphasize the current developments with novel zirconia compositions with an improved balance between mechanical properties and long-term stability.
Materials Science & Engineering Dept.