Basic Properties of Carbonate Apatite Cement Consisting of Vaterite and Dicalcium Phosphate Anhydrous
The aim of the present study is to fabricate bone cement that could transform to carbonate apatite (CO3Ap) completely at body temperature. The powder phase of vaterite and dicalcium phosphate anhydrous (DCPA) was mixed with 0.8 mol/L of NaH2PO4, Na2HPO4, and Na3PO4 aqueous solution, respectively, with liquid to powder ratio (L/P ratio) of 0.45, 0.55, and 0.65. The paste was packed into split stainless steel mold, covered with the glass slide and kept at 37°C and 100% relative humidity for up to 96 hours (h). XRD analysis revealed that the cement became pure CO3Ap within 24 h for Na3PO4, 72 h for Na2HPO4, and 96 h for NaH2PO4, respectively. FT-IR results showed that all of the obtained specimens could be assigned to B-type CO3Ap. CHN analysis showed the carbonate content of the specimen were 10.4 ± 0.3% for NaH2PO4, 11.3 ± 0.7% for Na2HPO4, and 11.8 ± 0.4% for Na3PO4, respectively. Diametral tensile strength of the set CO3Ap cement was 1.95 ± 0.42 MPa for NaH2PO4, 2.53 ± 0.53 MPa for Na2HPO4, and 3.45 ± 1.53 MPa for Na3PO4, respectively. The set CO3Ap cement had low crystallinity similar to bone apatite since it was synthesized at body temperature. We concluded, therefore, that CO3Ap cement prepared from the present method has higher possibility to be used as an ideal bone replacement.
Kunio Ishikawa and Yukihide Iwamoto
A. Cahyanto et al., "Basic Properties of Carbonate Apatite Cement Consisting of Vaterite and Dicalcium Phosphate Anhydrous", Key Engineering Materials, Vols. 529-530, pp. 192-196, 2013