Effect of ZrO2 addition on in-vitro bioactivity and mechanical properties of SiO2-Na2O-CaO-P2O5 bioactive glass-ceramic

Herein, a multicomponent bioactive glass (0Z, 46SiO2-30CaO-18Na2O-6P2O5, wt.%) is prepared via melting. ZrO2 is introduced into the bioglass using two different methods, and then three types of glass-ceramic bulks are manufactured using low-cost pressureless sintering. The effect of ZrO2 addition on the bioactivity and mechanical properties of the bioactive glass-ceramic is assessed. The results indicate that the main crystalline precipitate from the bioactive glass-ceramic is Na2Ca(Si2O6). The crystallisation ability of the 5Z glass-ceramic, bioactive glass-ceramic with ZrO2 added during melting at high temperature, is reduced because ZrO2 participated in the reconstruction of the glass network. Further, the ZrO2 addition led to a low rate of cation release when soaked in simulated body fluid, indicating a decreased bioactivity. At the same time, the 5Y bioactive glassceramic, prepared by mixing YSZ particles with 0Z using ball-milling, possesses not only the highest mechanical strength (about twice the strength of 0Z) but also a high bioactivity. This study presents a promising method for the production of excellent bioactive glass-ceramic and a candidate (5Y) for the clinical applications where load bearing is required.