Fluoride-containing bioactive glasses: some aspects of reactivity in simulated body solutions

Bioactive glasses are used in medical field as bone regenerativematerials. They promote the growth of bone tissue on their surface, and establishinterconnections in order to form a continuum with the tissue. The bioactivity of thisclass of materials, immersed in a real or simulated biological medium, is monitored bythe ability to form at its surface a layer of Ca-phosphate, which ought to crystallizein the form of either hydroxy-apatite (HA) or hydroxy-carbonate-apatite (HCA).The present contribution deals with the activity/reactivity of some oxidic materials(to be possibly used as bio-active glasses) that: i) have been produced throughthe conventional melt-quench-grind method; ii) belong to the family of Hench’sBioglass (H-glass); iii) have been modified, in respect of H-glass composition, bythe introduction of variable amounts of Ca-fluoride. In assessing the bioactivity oftwo families of F-modified glasses, it is herewith shown that the use of some physico-chemical methods, typical of surface chemistry (e.g., surface area determination, IRand Raman vibrational spectroscopic analysis), gives indeed access to what happensat the interface between a complex oxidic material and the surrounding biologicalmedium.