Exploring the use of silica sands and calcite from natural deposits to prepare bioactive glasses

Nowadays bioactive glasses represent one of the most successful bioceramics used for bone tissue restorations. In this work, three types of silica sands (White, Yellow and Gray Sands) and calcite from Cuban natural deposits were employed to synthesize glasses from the system SiO2–CaO–Na2O. The ions released from glasses were evaluated through in vitro tests in Tris-HCl and in simulated body fluids. All sands had purity around 99.2% of SiO2and contained traces (ppm) of Zr, Cr, Ba, Ce and Sr ions, while calcite raw material had traces of Sr, Cr, Zr, Ce and Zn. All glasses induced a pHchange in Tris-HCl from 7.4 to 9 after 24 h; they had similar ion-release behavior in the in vitro solutions tested and showed a significant bioactive performance after 5 h. This work illustrates the potentialities of the use of natural resources to develop medical products when recognized trademark materials are not available.