Novel fast-setting chitosan/β-dicalcium silicate bone cements with high compressive strength and bioactivity

Novel rapid-setting root-canal filling and substitute materials consisting of chitosan oligosaccharide (COS) calcium silicate bone cements (CSCs) were developed. Sol–gel technique was used to prepare calcium silicate powders with different molar ratios of CaO/SiO2 ranging from 3:7 to 7:3. A hybrid cement was prepared using COS-containing calcium silicate powder in a solid phase and distilled water in liquid phase. Phase composition, morphology, and in vitro bioactivity of the hybrid cement were investigated after mixing with water, in addition to setting time and compressive strength (CS). The setting times for cements derived from powders with different Ca/Si ratios ranged from 13 to 51 min and were lower for cements with higher starting CaO content. CS values of CSCs ranged from 1.31 to 15.53 MPa, and these values were significantly different (P<0.05). The hybrid cement derived from the powders with CaO/SiO2=5:5 had setting times of 10, 14, 31, 49 min and CS values of 17.26, 25.02, 18.06, 16.63 MPa, respectively, when containing 2.5%, 5%, 7.5% and 10% COS. The results of in vitro biological experiments indicated that the hybrid cement containing 5% COS formed apatite in simulated body fluid (SBF) for different time points. It was concluded that the bioactivity of the 5% COS-containing CSCs makes it an attractive choice for root-canal filling and vertebroplasty.