Huysmans M C, Hintze H, Wenzel A
TRIKON: Institute for Dental Clinical Research, Department of Cariology and Endodontology, University of Nijmegen, The Netherlands.
Eur J Oral Sci. 1997 Feb;105(1):15-20. doi: 10.1111/j.1600-0722.1997.tb00175.x.
The aim of this study was to determine the in vitro diagnostic performance for approximal caries and occlusal dentine caries diagnosis of the Digora system for digital radiography in relation to the exposure time. Radiographs were made of 220 extracted human posterior teeth and cuspids at exposure time levels of 3%, 6%, 10%, 20%, and 78% of the exposure time needed for E-speed film (image sets I, II, III, IV, and V, respectively). The image sets were put in random order (III, I, IV, II, V) and assessed independently by 3 observers using a 5-point confidence scale. True caries status was determined histologically after sectioning of the teeth. Evaluated parameters were: interexaminer kappa, sensitivity, specificity, Dz3/4 (the distance of one operating point to the diagonal in the ROC domain) and area under the ROC curve. The Spearman correlation coefficients between the parameters and both exposure time and order of viewing of the sets were calculated. For approximal surfaces, the ranges of mean parameter values were: sensitivity 26-33%, specificity 93-95%, Dz3/4 0.63-0.84, area 0.61-0.69. For occlusal surfaces, the ranges were: sensitivity 52-60%, specificity 91-95%, Dz3/4 1.03-1.34, area 0.79-0.87. Out of 24 pairwise comparisons between sets V and I, 5 were significant. Out of 24 comparisons between set V and II, only 2 were significant. It was concluded that diagnostic performance is unlikely to be impaired for an exposure time as short as 6% of E-speed film exposure. When reducing the exposure time to 3% of E-speed film exposure, caries diagnosis may be impaired.
本研究的目的是确定Digora数字射线摄影系统在不同曝光时间下对邻面龋和咬合面牙本质龋的体外诊断性能。对220颗拔除的人类后牙和尖牙进行射线摄影，曝光时间分别为E速胶片所需曝光时间的3%、6%、10%、20%和78%（分别为图像集I、II、III、IV和V）。图像集按随机顺序排列（III、I、IV、II、V），由3名观察者使用5分置信度量表独立评估。牙齿切片后通过组织学确定真实龋病状态。评估参数包括：检查者间kappa值、敏感性、特异性、Dz3/4（ROC域中一个操作点到对角线的距离）和ROC曲线下面积。计算参数与曝光时间和图像集观看顺序之间的Spearman相关系数。对于邻面，平均参数值范围为：敏感性26 - 33%，特异性93 - 95%，Dz3/4 0.63 - 0.84，面积0.61 - 0.69。对于咬合面，范围为：敏感性52 - 60%，特异性91 - 95%，Dz3/4 1.03 - 1.34，面积0.79 - 0.87。在图像集V和I之间的24对比较中，有5对具有显著性差异。在图像集V和II之间的24次比较中，只有2次具有显著性差异。研究得出结论，对于低至E速胶片曝光时间6%的曝光，诊断性能不太可能受到损害。当将曝光时间减少到E速胶片曝光时间的3%时，龋病诊断可能会受到损害。
