Influence of Ta₂O₅ doping on mechanical and biological properties of silicate glass-ceramics

The mechanical properties of silicate glass-ceramics were evaluated based on the compressive strength tests. It was found that Ta₂O₅ addition improved densification, refinement of the microstructure and toughening of the bodies. The maximum compressive strength of the bodies with 1 mol% Ta₂O₅ was increased 3-fold (245.92 ±0.3 MPa) in comparison to undoped glass-ceramics which was measured to be 89.04 ±0.3 MPa, while for 3 mol% it became 4-fold (387.12 ±0.4 MPa) greater. The addition of Ta₂O₅ stabilized the system by controlling the biodegradation of the glass-ceramics. It effectively depressed the apatite formation as by addition of 3 mol% Ta₂O₅ no apatite layer was observed. It may be concluded from this study that mechanical and physical properties can be improved by the addition of Ta₂O₅, but at a cost of bioactivity. Still the optimized composition having Ta₂O₅ ⩽ 1 mol% may provide appropriate strength of biomaterials for high load bearing applications.