Zaman Chowdury Tanira, Takeuchi Akari, Matsuya Shigeki, Zaman Q H M Shawket, Ishikawa Kunio
Department of Biomaterials, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
Dent Mater J. 2008 Sep;27(5):710-5. doi: 10.4012/dmj.27.710.
B-type carbonate apatite (CO3Ap) block may be an ideal artificial bone substitute because it is closer in chemical composition to bone mineral. In the present study, the feasibility to fabricate CO3Ap blocks was investigated using compositional transformation, which was based on the dissolution-precipitation reaction of a gypsum-calcite composite with free-molding behavior. For the compositional change, or phosphorization, gypsum-calcite composites of varying CaCO3 contents were immersed in 1 mol/L (NH4)3PO4 aqueous solution at 100 degrees C for 24 hours. No macroscopic changes were found after the treatment, whereas microscopic change was observed at SEM level. X-ray diffraction, Fourier transform infrared spectroscopy and CHN analysis indicated that the composites were B-type CO3Ap containing approximately 6-7 wt% of CO3, a value similar to that of biological bone apatite. Diametral tensile strength of the CO3Ap block was approximately 1-3 MPa. Based on the results obtained, it was therefore concluded that gypsum-calcite was a good candidate for the fabrication of CO3Ap blocks, coupled with the advantage that the composite can be molded to any shape by virtue of the setting property of gypsum.
B型碳酸磷灰石（CO3Ap）块可能是一种理想的人工骨替代物，因为其化学成分与骨矿物质更为接近。在本研究中，利用基于石膏-方解石复合材料溶解-沉淀反应的成分转变来研究制备CO3Ap块的可行性，该复合材料具有自由成型特性。对于成分变化或磷酸化，将不同CaCO3含量的石膏-方解石复合材料在100℃下浸泡于1mol/L的(NH4)3PO4水溶液中24小时。处理后未发现宏观变化，而在扫描电子显微镜（SEM）水平观察到微观变化。X射线衍射、傅里叶变换红外光谱和CHN分析表明，复合材料为含有约6-7wt% CO3的B型CO3Ap，该值与生物骨磷灰石的值相似。CO3Ap块的径向拉伸强度约为1-3MPa。基于所获得的结果，因此得出结论，石膏-方解石是制备CO3Ap块的良好候选材料，同时该复合材料凭借石膏的凝固特性可被模制成任何形状。
