Tjäderhane L, Hietala E L, Larmas M
Institute of Dentistry, University of Oulu, Finland.
J Dent Res. 1995 Nov;74(11):1770-4. doi: 10.1177/00220345950740110901.
We recently demonstrated the advantages of back-scattered electron images (COMPO) in the visualization of dentinal caries, and the relationship of the change in the dentin fluorescence pattern in caries lesions. However, the exact nature of these changes is not known. In this paper, the nature of the changes in the areas with reduced mineral content in COMPO images was investigated. We examined the relation of changes in mineral elements and the appearance of soft carious and sound dentin in COMPO images using a scanning electron microscope (SEM) equipped with an electron probe microanalyzer (EPMA). Rat molars with small dentinal caries lesions just under the DEJ were chosen for the study. The Ca, P, Na, Mg, Zn, F, and total contents were determined by EPMA from five different dentin sites, and the Ca/P and Mg/Ca ratios were calculated. Generally, the lowest contents were found in caries lesions and highest in mantle dentin, with the exceptions of Mg and Zn. The Ca/P ratio was lowest in mantle dentin and highest in carious dentin. The results confirm that the change in fluorescence in the dentinal caries lesion is correlated with the very initial changes in mineral content, and that EPMA used in combination with COMPO images is a useful tool for determining small changes in mineral elements in the carious and adjacent areas of dentin.
我们最近证明了背散射电子图像（COMPO）在牙本质龋可视化方面的优势，以及龋损中牙本质荧光模式变化之间的关系。然而，这些变化的确切性质尚不清楚。在本文中，我们研究了COMPO图像中矿物质含量降低区域变化的性质。我们使用配备电子探针微分析仪（EPMA）的扫描电子显微镜（SEM），研究了COMPO图像中矿质元素变化与软龋和完好牙本质外观之间的关系。本研究选用了在牙本质-釉质界（DEJ）下方有小的牙本质龋损的大鼠磨牙。通过EPMA测定了五个不同牙本质部位的钙、磷、钠、镁、锌、氟和总含量，并计算了钙/磷和镁/钙比值。一般来说，龋损中的含量最低，罩牙本质中的含量最高，但镁和锌除外。钙/磷比值在罩牙本质中最低，在龋坏牙本质中最高。结果证实，牙本质龋损中荧光的变化与矿物质含量的最初变化相关，并且EPMA与COMPO图像结合使用是确定龋坏牙本质及相邻区域矿质元素微小变化的有用工具。
