Elshahawy Waleed, Watanabe Ikuya, Koike Mari
Department of Biomaterials Science, Baylor College of Dentistry, Texas A&M Health Science Center, 3302 Gaston Ave., Dallas, TX 75246, USA.
Dent Mater. 2009 Aug;25(8):976-81. doi: 10.1016/j.dental.2009.02.004. Epub 2009 Mar 20.
Elemental release is important because it plays a significant role in material biocompatibility. The aim of this study was to investigate the release of metal ions from four fixed prosthodontic materials.
Specimens were prepared using the conventional lost wax technique for gold and nickel-chromium (Ni-Cr) alloys, and by cutting blocks and bar for CAD-CAM ceramic and stainless-steel (St-St) alloy, respectively. All specimens were polished (600grit SiC paper), and ultrasonically cleaned with ethanol for 5min. After they were immersed in 0.9% sodium chloride (NaCl) and 1% lactic acid, and were kept at 37 degrees C for 7 days, the elemental release (mug/cm(2)) from each material was analyzed by using inductively coupled plasma mass spectroscopy. The rate (n=5) was statistically analyzed by ANOVA/Tukey test (p<0.05). Two immersion blank solutions were used as a negative control group.
Higher elemental release (mean+/-S.D.) of all elements from all materials was evident into the lactic acid solution except for Ag. In the gold alloy, there was significant difference (p<0.05) between Zn and other released elements in the NaCl solution, and it also revealed significant difference between Pd or Ag and Cu which detection value was more than Zn (but no statistical difference) into lactic acid solution. The Ni was significantly more released from Ni-Cr alloy than the other elements into both NaCl and lactic acid solutions. The same was observed for Fe released from St-St alloy. There was more significant release of K than Al from CAD-CAM ceramic in only NaCl solution.
Transient exposure of tested materials to an acidic environment is likely to significantly increase the elemental release from them. The significant higher release of Ni from Ni-Cr alloy, and Zn, Cu from gold alloy was evident.
元素释放很重要，因为它在材料生物相容性方面起着重要作用。本研究的目的是调查四种固定义齿修复材料中金属离子的释放情况。
采用传统失蜡法分别制备金合金和镍铬（Ni-Cr）合金标本，通过切割块体和棒材分别制备计算机辅助设计与制造（CAD-CAM）陶瓷和不锈钢（St-St）合金标本。所有标本均用（600目碳化硅砂纸）抛光，并用乙醇超声清洗5分钟。将它们浸泡在0.9%氯化钠（NaCl）和1%乳酸中，在37℃下保存7天，然后使用电感耦合等离子体质谱法分析每种材料的元素释放量（微克/平方厘米）。对速率（n=5）进行方差分析/ Tukey检验统计分析（p<0.05）。使用两种浸泡空白溶液作为阴性对照组。
除银外，所有材料中所有元素在乳酸溶液中的元素释放量（平均值±标准差）均较高。在金合金中，锌与氯化钠溶液中其他释放元素之间存在显著差异（p<0.05），在乳酸溶液中，钯或银与检测值高于锌的铜之间也存在显著差异（但无统计学差异）。在氯化钠和乳酸溶液中，镍从Ni-Cr合金中的释放量均显著高于其他元素。从St-St合金中释放的铁也观察到同样的情况。仅在氯化钠溶液中，CAD-CAM陶瓷中钾的释放量比铝的释放量更显著。
测试材料短暂暴露于酸性环境可能会显著增加其元素释放量。Ni-Cr合金中镍的释放量显著更高，金合金中锌和铜的释放量也很明显。
