Reinforcement of calcium phosphate cement by incorporating with high-strength β-tricalcium phosphate aggregates

Calcium phosphate cement (CPC) sets to form hydroxyapatite after implantation and has been used in orthopedic and dental procedures. However, the brittleness and low strength of CPC prohibit its use in many stress-bearing locations, and so the improvement of the compressive strength is one of the focuses of research on CPC. In this study, a novel way was used to improve the mechanical performance of CPC by dispersion of high-strength degradable β-tricalcium phosphate (β-TCP) granules sized between 200 μm and 450 μm in the cement as aggregates. Intimate bonding was formed between the aggregates and CPC matrix after hydration. The results showed that, by addition of 20 wt % the as-prepared β-TCP aggregates, the compressive strength of the calcium phosphate cement was increased by about 70%, while the paste of the CPC concrete still maintained injectable, and the heat release decreased obviously (about 25%) in the hydration process. The high strength or high rigidity of the β-TCP aggregates and good interfacial bonding between the aggregates and the CPC matrix seemed to contribute to the significant improvement in the mechanical performance.