Preparation and Characterization of Low Temperature Heat-Treated 45S5 Bioactive Glass-Ceramic Analogues

AbstractThe 45S5 Bioglassr and its sintered bioactive glass-ceramic (BGC) have been widely investigated as bone implants, mainly for its ability to bond to hard tissues. However, high temperature treatment is not enough to improve its poor mechanical properties, but compromise its biologically relevant performances. The innovative BGC compositions based on the thermally treated 45S5 Bioglassr were developed by decreasing the P2O5 quantity and adding B2O3 (0-6%) into the Na2O–2CaO–3SiO2- based bioactive glasses (BG). The thermally treated BGCs were fully characterized from the microstructural and mechanical points of view and compared to each other. Their bioactivity and bio-dissolutionwere established by means of in vitro soaking tests. The new B2O3-added 45S5 BG analogues, named NCS-xB, can be transformed to crystalline phase (Na2Ca2Si3O9)-based BGCs of high compactness and bioactivity at a relatively low temperature heat treatment (≤ 900ºC), since their bioactivity is preserved. Our experimental results suggest that the new 45S5 BGC analogues with optimized composition exhibit improved micro- structural and mechanical properties, and are beneficial for making specific products such as porous scaffolds or composites for bone defect repair.