Abstract: A bioactive glass is an excellent candidate as a graft for bone tissue regeneration. The insertions of atomic elements such as Zn, Sr and/or Mg, separately or simultaneously, present a high interest in the bone metabolism activity. They were introduced as trace elements at different contents in the glass matrix, according to their concentration in the bone matrix. Their effects consist on the modification of physico-chemical properties of bioactive glass after "in vitro" or "in vivo" experiments. Their role is consequently the improvement of the properties such as crystallographic structure, morphology and density of the apatite layer formation on the surfaces of biomaterials and the bone-bonding ability. In this work, bioactive glass in the ternary system (SiO2-CaO-Na2O-P2O5) was elaborated by an original method based on the melting process. Additions of these atomic elements have been made with different amounts of each introduced element in the glassy network.
In vitro experiments were achieved to evaluate the crystallographic structure, the morphology and the kinetic of chemical reactivity versus time of soaking in synthetic physiological solution (SBF). Cells adhesion and proliferation on the surfaces of biomaterials were investigated.
In vivo experiments were carried out on the femurs of rabbits to evaluate the biocompatibility, the physico-chemical properties and the kinetic of bioactivity and bioconsolidation in the interface bone-Implant. Several physicochemical and biological methods were employed to highlight the behavior of pure and doped bioactive glass.
Obtained results show different behavior. The ppresence of magnesium promotes the dissolution of silica network when the presence of strontium or zinc slows down this phenomenon. All doped bioactive glasses show the no toxic character of these biomaterials. However, the introduction of strontium enhances the cells proliferation of about 14.3 % compared to pure bioactive glass.
In vivo experiments demonstrate that 10% BG-Sr seem to be the best implant materials tested leading to beneficial effects in stabilization of the oxidative balance. These beneficial effects were confirmed by histological findings and correlated with the biocompatibility of cells grown. These biomaterials offer to surgeons more opportunities. Because of the variations of the kinetic of bioactivity, they can be adapted for patients according to different parameters such as the age, the gender, the location site and other physiological parameters.

Brief Biography of the Speaker:
Hassane Oudadesse graduated from the University Blaise Pascal of Clermont-Ferrand France. He obtained his PhD in 1989 and worked as associate Professor and obtained his HDR (Habilitation a Diriger des recherches) in 1998. Since 2001, he works in the University of Rennes 1 as Full Professor in the "Sciences Chimiques de Rennes", UMR CNRS 6226.
His works concern the conception, synthesis and physicochemical studies of new biomaterials for applications in orthopaedic surgery. Biocompatibility, kinetic of bioactivity, kinetic of bio consolidation in the interface bone-Implants, cells enhancement and other properties of biomaterials present the research filed of Professor Hassane Oudadesse.
He is author of more than 80 articles published in international journals and 50 international conferences.
Professor Hassane Oudadesse is a Head of the research unit on Biomaterials since 2001, Vice-President of University of Rennes 1, human resources since 2008, Director of Master 2 Solid State Chemistry and Materials since 2006. He was the President of the Chemical Department from 2002 to 2004 and the President of the specialists commission CNU 33 (Materials Chemistry) from 2003 to 2008.