Center for Medical Image Science and Visualisation (CMIV), University Hospital Linköping, Linköping University, 58185 Linköping, Sweden.
Eur J Radiol. 2011 Nov;80(2):432-40. doi: 10.1016/j.ejrad.2010.06.012. Epub 2010 Jul 7.
The aim of this study was to evaluate the use of high resolution CT to radiologically define teeth filling material properties in terms of Hounsfield units after high temperature exposure.
122 human molars with 10 different filling materials at defined filling diameters were examined. The teeth were CT scanned both before and after the exposure to different temperatures. After image reconstruction, the teeth and filling materials were analyzed regarding their morphology and Hounsfield units (HU) using an extended HU scale.
The majority of filling materials diminished in size at temperatures≥400 °C. HU values were stable for all materials up till 200 °C, and only slightly changed up to 600 °C. Cerec, Dyract and dentin showed only minor changes in HU at all temperatures. The other materials, inclusive enamel, showed specific patterns, either increasing or decreasing in HU with increasing temperatures over 600 °C.
Over 600 °C the filling materials show specific patterns that can be used to discriminate filling materials. Ultra high resolution CT may improve the identification processes in fire victims. Existing 3D visualization presets for the dentition can be used until 600 °C and have to be optimized for bodies exposed to higher temperatures.
本研究旨在评估高温暴露后使用高分辨率 CT 根据亨氏单位值来对牙齿填充材料特性进行影像学定义。
对 122 颗具有 10 种不同填充材料的人磨牙进行了研究，填充直径均相同。将这些牙齿分别在暴露于不同温度之前和之后进行 CT 扫描。在图像重建后，使用扩展的 HU 范围分析牙齿和填充材料的形态和亨氏单位（HU）。
在≥400°C 的温度下，大多数填充材料的尺寸减小。所有材料的 HU 值在 200°C 之前保持稳定，在 600°C 之前仅略有变化。Cerec、Dyract 和牙本质在所有温度下的 HU 值变化都很小。其他材料，包括牙釉质，在超过 600°C 的温度下，随着温度的升高，HU 值呈现出特定的增加或减少模式。
在 600°C 以上，填充材料会显示出特定的模式，可以用来区分填充材料。超高分辨率 CT 可能会提高在火灾受害者中的识别过程。现有的牙齿 3D 可视化预设可以在 600°C 以下使用，但必须针对暴露于更高温度的尸体进行优化。
