Objective

Ex-vivo evaluation of the detectability of vertical root fractures (VRFs) using digital subtraction radiography (DSR) and conventional digital periapical radiography (CDPR); investigation of the effect of root canal filling, x-ray angulation, and thickness of the VRF in the diagnostic accuracy.

Materials and methods

Sixty root canals were mechanically prepared and radiographed either with a gutta-percha root canal filling or without, at 0^o and ± 10^o. VRFs were introduced with a universal testing machine. The width and angulation of the fracture line with the radiographic beam were calculated. DSR was performed comparing radiographs obtained prior to and after the VRF induction. Five examiners evaluated the resultant images and analysis was performed using receiver operator characteristic (ROC) statistics and binary logistic regression tests.

Results

No significant differences in sensitivity, specificity, and the areas under the ROC curves (AUC) between the CDPR and DSR were detected (p > 0.05), except for root canal filled teeth where the AUC for DSR was higher (p < 0.05). Using DSR, a VRF was 1.3 times more likely to be diagnosed [95% confidence intervals (CI): 1.045–1.59; p = 0.018]. A correct diagnosis was 2.399 times more likely to occur in non-filled teeth regardless of the radiographic technique (95% CI 1.940–2.965; p = 0). The regression coefficients were positive for width and negative for angle.

Conclusions

DSR showed a better diagnostic accuracy of VRFs compared with CDPR, in single root canal filled teeth. The angulation, the width, and the presence of a root canal filling affected the diagnostic potential.

Clinical relevance

DSR is a cost- and time-effective imaging technique that could contribute in early diagnosis of VRFs.

中文翻译：

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数字减影射线照相术在垂直根部骨折的检测中：对根管充盈，骨折方向和宽度变量的准确性评估。一项离体研究。

目的

使用数字减影X线摄影（DSR）和常规数字根尖X线摄影（CDPR）进行离体评估垂直根部骨折（VRF）的可检测性；研究根管充盈，X射线成角度和VRF厚度对诊断准确性的影响。

材料和方法

机械制备60条根管，并在0 ^o和±10 ^o处用牙胶-percha根管充填或不加胶乳进行放射照相。VRF随通用测试机一起推出。计算了放射线在骨折线上的宽度和角度。通过比较在VRF诱导之前和之后获得的射线照片进行DSR。五名检查员评估了所得图像，并使用接收者操作员特征（ROC）统计数据和二进制逻辑回归测试进行了分析。

结果

 除根管充填的牙齿的DSR的AUC较高（p  <0.05）外，CDPR和DSR之间的敏感性，特异性和ROC曲线下面积（AUC）均未检测到显着差异（p > 0.05）。使用DSR，诊断出VRF的可能性高1.3倍[95％置信区间（CI）：1.045–1.59；p  ＝ 0.018]。不管采用哪种射线照相技术，正确的诊断结果都是未填充的牙齿发生率高2.399倍（95％CI 1.940–2.965；p  = 0）。回归系数的宽度为正，角度为负。

结论

与CDPR相比，DSR在单根管充盈的牙齿中显示出更好的VRF诊断准确性。角度，宽度和根管充盈影响了诊断潜力。

临床相关性

DSR是一种节省成本和时间的成像技术，可有助于VRF的早期诊断。