Matsuya S, Matsuya Y, Ohta M
Department of Dental Materials Engineering, Kyushu University, Fukuoka, Japan.
Dent Mater J. 1999 Jun;18(2):155-66. doi: 10.4012/dmj.18.155.
We prepared a new glass ionomer cement using bioactive CaO-P2O5-SiO2(-MgO) glass and investigated its setting process using FT-IR and MAS NMR analyses. The compressive strengths of the cements depended on the glass composition and a maximum strength of 33.3 +/- 4.7 MPa was obtained using cement with the glass composition of MgO:4.6, CaO:44.9, SiO2:34.2 and P2O5:16.3% in weight. FT-IR analysis showed that the COOH group in the polyacrylic acid decreased and carboxylate ion (COO-Ca2+) increased after the setting reaction. A broad signal appeared around -82 ppm in 29Si MAS-NMR spectra of the glass and a new signal corresponding to hydrated silica gel formation appeared around -102 and -111 ppm after setting. This suggests that Ca2+ was released from the glass powder to form carboxylate salt and that a degree of polymerization in the silicate network increased. The setting mechanism of the cement was found to be essentially the same as in conventional glass ionomer cement.
我们使用生物活性CaO-P2O5-SiO2（-MgO）玻璃制备了一种新型玻璃离子水门汀，并通过傅里叶变换红外光谱（FT-IR）和魔角旋转核磁共振（MAS NMR）分析研究了其凝固过程。水门汀的抗压强度取决于玻璃成分，使用MgO:4.6、CaO:44.9、SiO2:34.2和P2O5:16.3%（重量）玻璃成分的水门汀可获得33.3±4.7MPa的最大强度。FT-IR分析表明，凝固反应后聚丙烯酸中的COOH基团减少，羧酸根离子（COO-Ca2+）增加。在玻璃的29Si MAS-NMR谱中，-82ppm附近出现一个宽信号，凝固后在-102ppm和-111ppm附近出现一个对应于水合硅胶形成的新信号。这表明Ca2+从玻璃粉末中释放出来形成羧酸盐，并且硅酸盐网络中的聚合度增加。发现该水门汀的凝固机制与传统玻璃离子水门汀基本相同。
