Investigating the effect of SiO₂-TiO₂-CaO-Na ₂O-ZnO bioactive glass doped hydroxyapatite: Characterisation and structural evaluation

The effects of increasing bioactive glass additions, SiO ₂-TiO₂-CaO-Na₂O-ZnO up to 25 wt% in increments of 5 wt%, on the physical and mechanical properties of hydroxyapatite (HA) sintered at 900, 1000, 1100 and 1200°C for 2 h was investigated. Increasing both the glass content and the temperature resulted in increased HA decomposition. This resulted in the formation of a number of bioactive phases. However the presence of the liquidus glass phase did not result in increased densification levels. At 1000 and 1100°C the additions of 5 wt% glass resulted in a decrease in density which never recovered with increasing glass content. At 1200°C a cyclic pattern resulted from increasing glass content. There was no direct relationship between strength and density with all samples experiencing no change or a decrease in strength with increasing glass content. Weibull statistics displayed no pattern with increasing glass content.