Dental Research Centre, Tehran University of Medical Sciences, Tehran, Iran.
Int Endod J. 2012 Nov;45(11):1004-9. doi: 10.1111/j.1365-2591.2012.02062.x. Epub 2012 May 2.
To compare the accuracy of digital radiography (DR), multidetector computed tomography (MDCT) and cone beam computed tomography (CBCT) in detecting vertical root fractures (VRF) in the absence and presence of gutta-percha root filling.
The root canals of 100 extracted human single-rooted teeth were prepared and randomly divided into four groups: two experimental groups with artificially fractured root and two intact groups as controls. In one experimental and one control group, a size 40, 0.04 taper gutta-percha cone was inserted in the root canals. Then DR, MDCT and CBCT were performed and the images evaluated. Statistical analyses of sensitivity, specificity and accuracy of each imaging technique in the presence and absence of gutta-percha were calculated and compared.
In the absence of gutta-percha, the specificity of DR, MDCT and CBCT was similar. CBCT was the most accurate and sensitive imaging technique (P < 0 .05). In the presence of gutta-percha, the accuracy of MDCT was higher than the other imaging techniques (P < 0.05). The sensitivity of CBCT and MDCT was significantly higher than that of DR (P < 0.05), whereas CBCT was the least specific technique.
Under the conditions of this ex vivo study, CBCT was the most sensitive imaging technique in detecting vertical root fracture. The presence of gutta-percha reduced the accuracy, sensitivity and specificity of CBCT but not MDCT. The sensitivity of DR was reduced in the presence of gutta-percha. The use of MDCT as an alternative technique may be recommended when VRF are suspected in root filled teeth. However, as the radiation dose of MDCT is higher than CBCT, the technique could be considered at variance with the principles of ALARA.
比较数字射线照相术（DR）、多排螺旋 CT（MDCT）和锥形束 CT（CBCT）在有无牙胶根管充填的情况下检测垂直根折（VRF）的准确性。
将 100 颗离体人单根牙的根管制备后随机分为四组：两组实验组的根有折裂，两组对照组的根完整。实验组和对照组之一的根管内插入 40 号、0.04 锥度牙胶尖。然后进行 DR、MDCT 和 CBCT 检查并评估图像。计算并比较每种成像技术在有无牙胶的情况下的敏感性、特异性和准确性的统计分析。
在没有牙胶的情况下，DR、MDCT 和 CBCT 的特异性相似。CBCT 是最准确和敏感的成像技术（P < 0.05）。有牙胶存在的情况下，MDCT 的准确性高于其他成像技术（P < 0.05）。CBCT 和 MDCT 的敏感性明显高于 DR（P < 0.05），而 CBCT 的特异性最低。
在本离体研究条件下，CBCT 是检测垂直根折最敏感的成像技术。牙胶的存在降低了 CBCT 的准确性、敏感性和特异性，但不影响 MDCT。DR 的敏感性在有牙胶存在的情况下降低。当怀疑有根充牙发生 VRF 时，建议使用 MDCT 作为替代技术。然而，由于 MDCT 的辐射剂量高于 CBCT，因此该技术可能与 ALARA 原则相违背。
