In vitro bioactivity assessment of 70 (Wt.)%SiO2-30 (wt.)%CaO bioactive glasses in simulated body fluid

In the present study, the bioactivity assessment of 70 (wt.)%SiO2-30 (wt.)%CaO bioactive glass was conducted using various amount ratios of bioactive glass to SBF solution, which were 10, 5, 3.3, 2.5 and 2 mg/ml, respectively. When the bioactive glasses were soaked in SBF solutions for the first 6 h, due to the high concentration of PO43- in the original SBF solutions, hydroxyl apatite (HA) crystalline phase were formed on the surfaces of all the bioactive glasses, regardless of the amount ratio of glass to SBF solution. After 6 h of soaking, except for the SBF solution with the amount ratio of 2 mg/mol, the other four SBF solutions were supersaturated for calcite. When the soaking duration was prolonged to 1 day, calcite crystalline phases were formed on the surfaces of the bioactive glasses soaked in SBF solutions with amount ratios of 10, 5, 3.3 and 2.5 mg/ml, respectively. In contrast, with the amount ratio of 2 mg/ml, there is no calcite crystalline phase formed on the surface of the bioactive glasses. (C) 2005 Elsevier B.V. All rights reserved.