Hesaraki Saeed, Sharifi Davood
Ceramic Department, Materials and Energy Research Center, Tehran, Iran.
Biomed Mater Eng. 2007;17(1):29-38.
Calcium phosphate cements (CPCs) are biocompatible and osteoconductive materials used in dental, craniofacial and orthopaedic applications. One of the most important advantages of these materials is their replacement with bone followed by resorption. Already several attempts have been made to improve the resorption behaviour of calcium phosphate cements by increasing the porosity of the material. In this investigation a mixture of NaHCO(3) and citric acid monohydrate was added to the apatite cement component as an effervescent additive for producing interconnected macropores into the cement matrix. Mercury intrusion porosimetry was employed to determine pore volume and pore size distribution in the calcium phosphate cement (CPC) samples. Results showed that addition of only 10 wt % of the effervescent additive (based on the cement powder) to the CPC components lead to producing about 20 V % macropores (with the size of 10 to 1000 mum) into the cement structure. The setting time was measured in an incubator at 37 degrees C and decreased from 40 min for additive-free CPC to about 14 min for CPC containing effervescent additive. Other properties of the CPCs such as compressive strength, phase composition, microstructure morphology and dissolution behavior were evaluated after immersing them in a simulated body fluid solution. The results showed that the rate of formation of poor crystalline apatite phase have been improved by production of macroporosity into the cement matrix.
磷酸钙骨水泥（CPCs）是用于牙科、颅面和骨科应用的生物相容性和骨传导性材料。这些材料最重要的优点之一是它们会被骨替代并随后被吸收。已经进行了几次尝试，通过增加材料的孔隙率来改善磷酸钙骨水泥的吸收行为。在本研究中，将碳酸氢钠和一水柠檬酸的混合物作为泡腾添加剂添加到磷灰石骨水泥组分中，以在水泥基质中产生相互连通的大孔。采用压汞法测定磷酸钙骨水泥（CPC）样品的孔体积和孔径分布。结果表明，仅向CPC组分中添加10 wt%的泡腾添加剂（基于水泥粉末）就会在水泥结构中产生约20 V%的大孔（尺寸为10至1000μm）。在37℃的培养箱中测量凝固时间，其从不含添加剂的CPC的40分钟降至含泡腾添加剂的CPC的约14分钟。将CPCs浸入模拟体液溶液后，评估了它们的其他性能，如抗压强度、相组成、微观结构形态和溶解行为。结果表明，通过在水泥基质中产生大孔隙率，改善了结晶性差的磷灰石相的形成速率。
