Improvements in phase stability and densification of β-tricalcium phosphate bioceramics by strontium-containing phosphate-based glass additive

beta-tricalcium phosphate (beta-TCP), which transforms to alpha-TCP at around 1125 degrees C, is characterized by poor sinterability. In this study, for the first time strontium containing phosphate-based glass (SPG) was used as a sintering additive for beta-TCP, which was sintered at 1250 degrees C. The results indicated that the SPG additive allowed for liquid state sintering of beta-TCP, thereby noticeably promoting the densification of beta-TCP bioceramics. In the sintering process SPG reacted with beta-TCP, and the metal ions from SPG were substituted for the calcium ions of beta-TCP. The SPG additive effectively inhibited the phase transformation of beta-TCP to alpha-TCP in the bioceramics. The compressive strength of porous beta-TCP bioceramics was markedly increased by introducing 10 wt% SPG. The SPG is considered as an effective sintering additive to improve the phase stability and mechanical strength of porous beta-TCP bioceramics.