Director of MATEIS laboratory University of Lyonand Deputy Director of Research at INSA-Lyon in charge of Health and Bioengineering.
Chapter 1 “Biomaterial Ceramic”
Low temperature degradation as aging of zirconia – does it affect implant performances ?
Zirconia exhibits the best mechanical properties of oxide ceramics: this is the consequence of phase transformation toughening, which increases its mechanical resistance. The high strength and toughness of zirconia is associated to an excellent biocompatibility and bone-integration, which makes it an excellent candidate and a credible alternative to titanium. However, it 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 some critical consequences in some biomedical fields. The subject has been treated by a large number of papers, both in-vitro and in-vivo but confusion still exists on the potential impact of aging on implants, in terms of functional performances. In this talk, we will briefly summarize the main aspects of the so-called ‘Low Temperature Degradation’ of zirconia, which stands to a progressive phase transformation of zirconia in presence of water or body fluids. We will then review our current analysis of state-of-the-art dental implants, which shows that current processing technologies, when they are well-controlled, insure a sufficient resistance to aging for prolonged duration. In addition, we will show that simple protocols can allow to assess mechanical reliability and lifetime on a given zirconia dental implant product.
Jérôme Chevalier is 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 behaviour laws of ceramics under different forms. He has been involved in a large number of European projects and has coordinated recently the LONGLIFE project on ceramic dental implants. He shows a strong involvement in partnerships with European companies. He has published more than 200 papers, holds 10 patents and has been cited more than 10000 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 one of the editors of the Journal of the European Ceramic Society. He is fellow of the European Ceramic Society (2017) and member of the World Academy of Ceramics (2018).