This study was aimed to evaluate the diagnostic accuracy of cone beam computed tomography (CBCT) in detecting noncavitated approximal caries at different exposure parameters and to assess the impact of artifacts generated by amalgam restorations in an in vitro study. Seventy-eight approximal surfaces of extracted teeth were prepared with intentionally created noncavitated approximal caries of different depths; then, thirteen teeth with class 2 amalgam restorations were replaced with one tooth with normal surfaces in each block. CBCT volumes for all teeth were acquired using a Planmeca Promax 3D Mid imaging unit before and after placement of amalgam teeth, with different exposure parameters at low and high definition, both applying and omitting the Metal Artifact Reduction algorithm. The lesions were classified into four groups with regard to lesion extension. All teeth underwent histological analysis as gold standard. The histological examination showed that the distribution of lesions was as follows: 39.8% sound, enamel lesions of less and more than half the enamel thickness each 17.8%, and 24.6% dentin lesions. The detection sensitivity was found to be 0.972%, and specificity was found to be 0.937% for the detection of noncavitated approximal initial enamel and dentin caries. The highest diagnostic accuracy was found when using operating parameters of 90 kV_p, 8 mA, and high resolution (75 μm) with nonamalgam teeth; all modes showed statistically significant higher AUCs than mode 2 (80 kV_p, 7 mA, and 75 μm). However, for teeth with amalgam restorations, the highest accuracy was obtained at low resolution (200 μm) with the other parameters kept the same. It could be concluded that increasing the peak voltage and current improves diagnostic accuracy for the detection of noncavitated approximal caries. Moreover, diagnostic accuracy was found to be higher upon using high spatial resolution when diagnosing caries without adjacent amalgam restorations. There is a statistically significant difference with and without amalgam with respect to all modes.

中文翻译：

---

汞齐修复和操作参数对使用锥形束计算机断层扫描进行龋齿检测诊断准确性的影响：一项体外研究

本研究旨在评估锥形束计算机断层扫描 (CBCT) 在不同暴露参数下检测非空洞近似龋的诊断​​准确性，并评估体外研究中汞合金修复体产生的伪影的影响。78 个拔牙近端面制备了有意制造的不同深度的非空洞近端龋齿；然后，在每个块中用一颗具有正常表面的牙齿替换了具有 2 级汞合金修复体的 13 颗牙齿。使用普兰梅卡 Promax 3D Mid 成像单元在放置汞合金牙齿之前和之后获取所有牙齿的 CBCT 体积，在低清晰度和高清晰度下使用不同的曝光参数，应用和省略金属伪影减少算法。病变根据病变范围分为四组。所有牙齿都进行了组织学分析作为金标准。组织学检查显示病变分布如下：39.8%健全，釉质厚度小于或超过一半的釉质病变各17.8%，牙本质病变24.6%。检测灵敏度为 0.972%，检测非空洞的近似初始牙釉质和牙本质龋的特异性为 0.937%。使用 90 kV 的操作参数时发现诊断准确度最高 检测灵敏度为 0.972%，检测非空洞的近似初始牙釉质和牙本质龋的特异性为 0.937%。使用 90 kV 的操作参数时发现诊断准确度最高 检测灵敏度为 0.972%，检测非空洞的近似初始牙釉质和牙本质龋的特异性为 0.937%。使用 90 kV 的操作参数时发现诊断准确度最高_p , 8 mA 和高分辨率 (75  μ m) 与九汞合金齿；所有模式均显示出统计学上显着高于模式 2（80 kV _p、7 mA 和 75  μ m）的AUC 。然而，对于使用汞合金修复的牙齿，在其他参数保持不变的情况下，在低分辨率 (200 μ m)下获得了最高的精度 。可以得出结论，增加峰值电压和电流可提高检测非空洞近似龋的诊断​​准确性。此外，在没有相邻汞合金修复体的情况下诊断龋齿时，使用高空间分辨率的诊断准确性更高。对于所有模式，使用和不使用汞合金都有统计学上的显着差异。