Novel tricalcium silicate/monocalcium phosphate monohydrate composite bone cement

In this paper, we obtained a novel bone cement composed of tricalcium silicate (Ca3SO5; C3S) and monocalcium phosphate monohydrate (MCPM). The weight ratio of MCPM in the cement is 0, 10, 20, and 30%. The initial setting time was dramatically reduced from 90 min to 30 min as the content of MCPM reached 20%. The workable paste with a liquid/powder (L/P) ratio of 0.8 mL/g could be injected for 2-20 min (nozzle diameter 2.0 mm). The pH variation of the composite cement in simulated body environment was obviously lowered. The compressive strength of the composite cement after setting for 4-28 days was slightly lower than that of the tricalcium silicate paste. The in vitro bioactivity was investigated by soaking in simulated body fluid for 7 days. The result showed that the novel bone cement had good bioactivity and could degrade in tris-(hydroxymethyl)-aminomethane-hydrochloricacid (Tris-HCI) solution. Our result indicated that the Ca3SiO5/MCPM paste had good hydraulic properties, bioactivity, and degradability. The novel bone cement could be a potential candidate as bone substitute. (C) 2007 Wiley Periodicals, Inc.