Evaluation of modified fluorcanasite glass-ceramics for bone tissue augmentation

Three novel fluorcanasite glass-ceramics were produced by controlled heat-treatment of glasses. Glass I had the stoichiometric fluorcanasite composition, Ca5Na4K2Si12O30F4 Glass 2 had an increased calcium concentration and Glass 3 contained P2O5. These glasses were then heat-treated in a two stage heat-treatment process to form fluorcanasite glass-ceramics. X-ray diffraction patterns showed that fluorcanasite (JCPDS 13-553) and frankamenite (JCPDS 45-1398) were the major crystalline phases in these glass-ceramics. Scanning electron microscopy (SEM) images from the fracture surfaces of these glass-ceramics, confirmed the interlocking blade like structure of fluorcanasite crystals. Castability of Glass 2 and Glass 3 were evaluated using lost wax casting method and both these glasses showed a good castability. In vitro biocompatibility of Glass 1, Glass 2, Glass 3 and Glass-Ceramics, obtained from two-stage heat-treatment was evaluated using cultured rat osteosarcoma (ROS) cells. SEM showed that cells had colonized the surfaces of fluorcanasite glass-ceramics to a greater degree than their parent glasses. It was concluded that controlled crystallisation improved the biocompatibility of these materials.