The in vivo performance of an alkali-free bioactive glass for bone grafting, FastOs BG, assessed with an ovine model.

Although bioactive glasses are successfully used as bone substitutes, recent studies have revealed that the high alkali content in these glasses leads to fast in vivo degradation rates that may not match the rate of new bone ingrowth. This prompted us to design and develop novel bioactive glasses that are devoid of alkali but still demonstrate high bioactivity in vitro. This article describes the in vivo performance of an alkali-free bioactive glass with the following composition (Wt %): 13.03 MgO-33.98 CaO-13.37 P O -38.84 SiO -0.77 CaF (labelled as FastOs BG). An animal model was used to assess the in vivo performance of FastOs BG, using 45S5 Bioglass as control. The evaluation was performed through implantation of FastOs BG and 45S5 Bioglass , during one month, in femoral bone defects in sheep. Subcutaneous implantation of both glasses was also performed in order to assess tissue response through a standardized method. Histological and scanning electron microscopy assessment of retrieved subcutaneous and bone samples demonstrated that FastOs BG is biocompatible, osteoconductive, that it can be osteointegrated, and that it is more slowly resorbed than 45S5 Bioglass . These features suggest that FastOs BG is a potential candidate for bone grafting. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 30-38, 2017.