Department of Oral Radiology, Faculty of Dentistry, Qazvin University of Medical Sciences, Qazvin, Iran.
Dent Traumatol. 2012 Dec;28(6):478-82. doi: 10.1111/j.1600-9657.2012.01120.x. Epub 2012 Feb 20.
Root fracture diagnosis is a clinical difficulty that in most cases can only be detected through radiography. The objective of this study was to compare the diagnostic accuracy of two types of digitally enhanced images (reverse-contrast and colorization) with original digital radiographies in detecting experimental root fractures. Two hundred extracted single-rooted human teeth were endodontically instrumented and then divided in two groups, one control group and one test group, including fractured teeth. Vertical root fractures were experimentally made in the fractured group. The digital image of each tooth was taken, using the paralleling technique. There were three groups of images: (i) original, (ii) reverse contrast, and (iii) colorized. Three experienced dental specialists examined the images with no prior knowledge of the distribution of the root fractures. Two-way analysis of variance was used to assess the differences in accuracy, sensitivity, and specificity of each technique in detecting root fractures. Cohen's kappa coefficients were calculated to investigate the degree of interobserver agreement. The accuracy, sensitivity, and specificity of original images were 67.4%, 66.7%, and 68%, respectively; these amounts were 61.5%, 61%, and 65.5% in reverse contrast images and 66.4%, 70.7%, and 62% in colorized digital radiography. The original images had the best inter observer kappa coefficients (between 0.45 and 0.55). The results showed that the accuracy of original images is better than reverse contrast and colorized images. Use of reverse-contrast and colorization digital images in root fracture detection should be regarded as an adjunct to other diagnostic methods not as a highly critical diagnostic aid.
根折的诊断是一个临床难点，在大多数情况下只能通过放射线检查来发现。本研究的目的是比较两种数字增强图像（反转对比和彩色化）与原始数字化射线照相在检测实验性根折中的诊断准确性。将 200 颗离体单根人牙进行根管器械预备，然后分为对照组和实验组，其中实验组包括有折裂的牙齿。在实验组中制作垂直根折。使用平行技术对每颗牙齿的数字图像进行拍摄。有三组图像：（i）原始图像，（ii）反转对比图像，和（iii）彩色化图像。三位有经验的牙科专家在不知道根折分布的情况下检查图像。使用双向方差分析评估每种技术检测根折的准确性、敏感性和特异性的差异。计算 Cohen's kappa 系数以评估观察者间一致性的程度。原始图像的准确性、敏感性和特异性分别为 67.4%、66.7%和 68%；反转对比图像分别为 61.5%、61%和 65.5%；彩色化数字射线照相分别为 66.4%、70.7%和 62%。原始图像具有最佳的观察者间kappa 系数（在 0.45 到 0.55 之间）。结果表明，原始图像的准确性优于反转对比和彩色化图像。在根折检测中使用反转对比和彩色化数字图像应被视为其他诊断方法的辅助手段，而不是高度关键的诊断辅助手段。
