Fathi Hawa, Johnson Anthony, van Noort Richard, Ward Jennie M, Brook Ian M
Department of Adult Dental Care, School of Clinical Dentistry, University of Sheffield, Claremont Crescent, Sheffield S10 2TA, UK.
Dent Mater. 2005 Jun;21(6):551-6. doi: 10.1016/j.dental.2004.07.018.
To assess the effect of varying CaF(2) on the chemical solubility of apatite-mullite glass-ceramic (G-C) materials in both the glassy and crystallized states.
Apatite-mullite forming glasses used in this study are ionomer cement derivatives based on the general formula (4.5SiO(2)-3Al(2)O(3)-1.5P(2)O(5)-3CaO-XCaF(2)). Six glass formulations were produced where X=0.5, 1, 1.5, 2, 2.5 and 3, and called HG1-6, respectively. Batches were melted in covered silliminite crucibles in a furnace overnight at 1050 degrees C, then at 1450 degrees C for 2h, before quenching in water. The six glass compositions were analyzed using differential thermal analysis (DTA), X-ray diffraction (XRD) and X-ray fluorescence spectrometry (XRF). Thirty discs (2mm thick and 12 mm diameter) were produced per glass using the lost wax casting technique. Ten were left as cast and 10 heat treated to either apatite or apatite-mullite. Solubility testing was carried out according to International Standard BS EN ISO 6872 1999 and the mass difference in solubility calculated as mug/cm(2). A lithium disilicate G-C system was used as a control material.
All compositions formed glasses and on heat treatment could form apatite and apatite-mullite. The as-cast glass samples were the most soluble followed by the apatite samples. The apatite-mullite G-C was significantly less soluble than the other two phases (p<0.05) for all six compositions. The control material was significantly less soluble than all the HG glass-ceramic compositions for every phase (p<0.05). Decreasing the CaF(2) content (3-0.5 mol%) led to a decrease in solubility, without affecting the ability of the material to form apatite and apatite-mullite phases.
Increasing the CaF(2) content increases the chemical solubility for the glass, apatite G-C and apatite-mullite G-C phases. The solubility values obtained show that all the compositions, as cast and heat treated would be suitable for use as core ceramics.
评估不同含量的CaF₂对磷灰石-莫来石微晶玻璃（G-C）材料在玻璃态和晶化态下化学溶解度的影响。
本研究中使用的形成磷灰石-莫来石的玻璃是基于通式（4.5SiO₂-3Al₂O₃-1.5P₂O₅-3CaO-XCaF₂）的离聚物水泥衍生物。制备了六种玻璃配方，其中X = 0.5、1、1.5、2、2.5和3，分别称为HG1-6。将批次物料在覆盖的硅线石坩埚中于炉中在1050℃下熔化过夜，然后在1450℃下保持2小时，之后在水中淬火。使用差示热分析（DTA）、X射线衍射（XRD）和X射线荧光光谱法（XRF）对这六种玻璃成分进行分析。使用失蜡铸造技术为每种玻璃制备30个圆盘（2mm厚，12mm直径）。10个保持铸态，10个进行热处理以形成磷灰石或磷灰石-莫来石。根据国际标准BS EN ISO 6872 1999进行溶解度测试，并将溶解度的质量差计算为μg/cm²。使用二硅酸锂G-C系统作为对照材料。
所有成分都形成了玻璃，并且在热处理后可以形成磷灰石和磷灰石-莫来石。铸态玻璃样品的溶解度最高，其次是磷灰石样品。对于所有六种成分，磷灰石-莫来石G-C的溶解度明显低于其他两个相（p<0.05）。对照材料在每个相中都明显比所有HG微晶玻璃成分的溶解度低（p<0.05）。降低CaF₂含量（3-0.5mol%）会导致溶解度降低，而不影响材料形成磷灰石和磷灰石-莫来石相的能力。
增加CaF₂含量会增加玻璃、磷灰石G-C和磷灰石-莫来石G-C相的化学溶解度。所获得的溶解度值表明，所有铸态和热处理后的成分都适合用作核陶瓷。
