Bioactivity and mechanical properties of Na_2O centre dot CaO centre dot SiO_2 centre dot P_2O_5 modified glasses

摘要

The purpose of this work was to study the influence of B_2O_3 and Al_2O_3 additions on the bioactivity and mechanical properties (modulus of rupture; MOR) of eight glasses in the Na_2O centre dot CaO centre dot SiO_2 centre dot P_2O_5 system, so that a bioactive glass with the good mechanical properties compares to others is obtained. For investigating their bioactive capacity these glasses were soaked in a simulated body fluid (SBF) at different time intervals. The changes in surface structure were examined by scanning electron microscopy (SEM) and EDX line scan and X-ray microanalysis to determine the compositional profiles through the substrate up to the surface. In some glasses the presence of a rich calcium and phosphorous layer was observed that, according to other studies, correspond to the apatite layer growing in all glasses with B_2O_3/Al_2O_3 ratio between 0.5 and 0.55. For MOR determination of these glasses, the three point loading test was used.