The self-setting properties and in vitro bioactivity of tricalcium silicate

In this study, tricalcium silicate (Ca3SiO5), as a new promising injectable bioactive material, was employed to investigate its physical and chemical properties for an injectable bioactive cement filler. The workable Ca3SiO5 pastes with a liquid to powder (L/P) ratio of 0.8–1.2 ml g−1could be injected for 15–60 min (nozzle diameter 2.0 mm). The setting process yielded cellular structures with compressive strength of 6.4–20.2 MPa after 2–28 days. The in vitro bioactivity of Ca3SiO5 paste was investigated by soaking in simulated body fluid (SBF) for various periods. The result showed that the Ca3SiO5 paste could induce hydroxyapatite (HA) formation and dissolve slowly in SBF. The result of indirect cytotoxicity evaluation indicated that Ca3SiO5 paste had a stimulatory effect on cell growth in a certain concentration range. The exothermic process showed that Ca3SiO5 had lower heat evolution rate during the hydration as compared to calcium phosphate cement (CPC). Our results indicated that Ca3SiO5 paste was bioactive and dissolvable, and it is a progressive candidate for further investigation as injectable tissue repairing substitute.