Dose-dependent behavior of bioactive glass dissolution.

The effect of glass dosage (0.001 g ml(-1) to 0.015 g ml(-1)) on the in vitro dynamic dissolution behavior of melt-derived 45S5 and sol-gel-derived 58S bioactive glasses, in simulated body fluid (SBF) at 37 degrees C, was evaluated. These glasses differ significantly in texture, especially the specific surface area and porosity, as a result of differences in manufacturing route. The concentrations of elements (Si, Ca, P, and Na) leached from the glasses into the dissolution medium, from 1 to 22 h, were evaluated with the use of induced coupled plasma analysis (ICP). The reacted powders were analyzed with the use of FTIR to observe the formation of a hydroxycarbonate apatite layer on the surface. The results show that the rate of HCA formation on both gel- and melt-derived bioactive glass powders in vitro depends on the concentration of the powders in solution. This result must be taken into account when carrying out in vitro cell-culture studies to simulate conditions in vivo and in experiments using extracts of the bioactive glass powders. Copyright 2001 John Wiley & Sons, Inc.