Biomaterials Chemistry Group, School of Science, University of Greenwich Medway Campus, Chatham, Kent ME4 4TB, United Kingdom.
J Biomater Appl. 2009 Nov;24(4):293-308. doi: 10.1177/0885328209344441. Epub 2009 Sep 8.
The role of aluminum in glass-ionomers and resin-modified glass-ionomers for dentistry is reviewed. Aluminum is included in the glass component of these materials in the form of Al(2)O(3) to confer basicity on the glass and enable the glass to take part in the acid-base setting reactions. Results of studies of these reactions by FTIR and magic-angle spinning (MAS)-NMR spectroscopy are reported and the role of aluminum is discussed in detail. Aluminum has been shown to be present in the glasses in predominantly 4-coordination, as well as 5- and 6-coordination, and during setting a proportion of this is converted to 6-coordinate species within the matrix of the cement. Despite this, mature cements may contain detectable amounts of both 4- and 5-coordinate aluminum. Aluminum has been found to be leached from glass-ionomer cements, with greater amounts being released under acidic conditions. It may be associated with fluoride, with which it is known to complex strongly. Aluminum that enters the body via the gastro-intestinal tract is mainly excreted, and only about 1% ingested aluminum crosses the gut wall. Calculation shows that, if a glass-ionomer filling dissolved completely over 5 years, it would add only an extra 0.5% of the recommended maximum intake of aluminum to an adult patient. This leads to the conclusion that the release of aluminum from either type of glass-ionomer cement in the mouth poses a negligible health hazard.
本文综述了铝在玻璃离子体和树脂改性玻璃离子体牙科材料中的作用。铝以 Al(2)O(3)的形式存在于这些材料的玻璃成分中，以赋予玻璃碱性，并使玻璃能够参与酸碱固化反应。通过傅里叶变换红外光谱（FTIR）和魔角旋转（MAS）-NMR 光谱研究这些反应的结果，并详细讨论了铝的作用。研究表明，铝主要以 4 配位形式存在于玻璃中，也存在 5 配位和 6 配位形式，在固化过程中，一部分铝会转化为基质中的 6 配位物种。尽管如此，成熟的水泥中可能仍含有可检测数量的 4 配位和 5 配位铝。已发现铝从玻璃离子体水泥中浸出，在酸性条件下释放量更大。它可能与氟化物有关，已知两者强烈络合。通过胃肠道进入人体的铝主要被排泄掉，只有约 1%的摄入铝会穿过肠壁。计算表明，如果玻璃离子体填充完全溶解在 5 年内，它只会给成年患者额外增加 0.5%的建议最大铝摄入量。这得出的结论是，口腔中任何一种玻璃离子体水泥释放的铝都不会对健康造成可忽略的危害。
