Abstract：
OBJECTIVE: This study aimed to assess the accuracy of ultra-low dose (ULD) cone-beam computed tomography (CBCT) for detection of proximal caries.
METHODS: This in vitro study evaluated 104 molar and premolar teeth. The teeth were mounted in dry skulls and underwent CBCT with four protocols of high-resolution (HR), normal (NORM), ULD-HR, and ULD-NORM; 78 CBCT images were scored by three observers for presence and penetration depth of caries twice with a 2-week interval using a 5-point Likert scale. The teeth were then sectioned and observed under a stereomicroscope (gold standard). The four protocols were compared with each other and with the gold standard. The receiver operating characteristic (ROC) curve was drawn, and the area under the curve (AUC) was calculated and compared by the Chi-square test (alpha = 0.05).
RESULTS: The interobserver agreement ranged from 0.5233 to 0.6034 for ULD-NORM, 0.5380 to 0.6279 for NORM, 0.5856 to 0.6300 for ULD-HR, and 0.6614 to 0.7707 for HR images. The intra-observer agreement ranged from 0.6027 to 0.8812 for ULD-HR, 0.7083 to 0.7556 for HR, 0.6076 to 0.9452 for ULD-NORM, and 0.7012 to 0.9221 for NORM images. Comparison of AUC revealed no significant difference between NORM and ULD-NORM (P > 0.05), or HR and ULD-HR (P > 0.05). The highest AUC belonged to HR (0.8529) and the lowest to NORM (0.7774).
CONCLUSIONS: Considering the significant reduction in radiation dose in ULD CBCT and its acceptable diagnostic accuracy for detection of proximal caries, this protocol may be used for detection of proximal carious lesions and assessment of their depth.
METHODS: This in vitro study evaluated 104 molar and premolar teeth. The teeth were mounted in dry skulls and underwent CBCT with four protocols of high-resolution (HR), normal (NORM), ULD-HR, and ULD-NORM; 78 CBCT images were scored by three observers for presence and penetration depth of caries twice with a 2-week interval using a 5-point Likert scale. The teeth were then sectioned and observed under a stereomicroscope (gold standard). The four protocols were compared with each other and with the gold standard. The receiver operating characteristic (ROC) curve was drawn, and the area under the curve (AUC) was calculated and compared by the Chi-square test (alpha = 0.05).
RESULTS: The interobserver agreement ranged from 0.5233 to 0.6034 for ULD-NORM, 0.5380 to 0.6279 for NORM, 0.5856 to 0.6300 for ULD-HR, and 0.6614 to 0.7707 for HR images. The intra-observer agreement ranged from 0.6027 to 0.8812 for ULD-HR, 0.7083 to 0.7556 for HR, 0.6076 to 0.9452 for ULD-NORM, and 0.7012 to 0.9221 for NORM images. Comparison of AUC revealed no significant difference between NORM and ULD-NORM (P > 0.05), or HR and ULD-HR (P > 0.05). The highest AUC belonged to HR (0.8529) and the lowest to NORM (0.7774).
CONCLUSIONS: Considering the significant reduction in radiation dose in ULD CBCT and its acceptable diagnostic accuracy for detection of proximal caries, this protocol may be used for detection of proximal carious lesions and assessment of their depth.
摘要：
目的：本研究旨在评估超低剂量（ULD）锥形束计算机断层扫描（CBCT）检测近端龋齿的准确性。
方法：这项体外研究评估了104颗磨牙和前磨牙。将牙齿安装在干燥的头骨中，并采用四种高分辨率（HR）方案进行CBCT，正常（NORM），ULD-HR,和ULD-NORM；三位观察者使用5分Likert量表对78张CBCT图像进行两次两次龋齿的存在和穿透深度评分，间隔2周。然后将牙齿切片并在立体显微镜(金标准)下观察。将四个方案相互比较，并与黄金标准进行比较。绘制受试者工作特性(ROC)曲线,计算曲线下面积（AUC），并通过卡方检验（α=0.05）进行比较。
结果：对于ULD-NORM，观察者之间的协议范围为0.5233至0.6034，0.5380到0.6279的NORM，0.5856至0.6300对于ULD-HR，和0.6614到0.7707的HR图像。ULD-HR的观察者内部协议范围为0.6027至0.8812，HR为0.7083至0.7556，ULD-NORM为0.6076至0.9452，和0.7012到0.9221的NORM图像。AUC比较显示NORM和ULD-NORM之间没有显着差异（P>0.05），或HR和ULD-HR(P>0.05)。最高的AUC属于HR（0.8529），最低的属于NORM（0.7774）。
结论：考虑到ULDCBCT中辐射剂量的显着降低及其对检测近端龋齿的可接受诊断准确性，该方案可用于检测近端龋损并评估其深度.
方法：这项体外研究评估了104颗磨牙和前磨牙。将牙齿安装在干燥的头骨中，并采用四种高分辨率（HR）方案进行CBCT，正常（NORM），ULD-HR,和ULD-NORM；三位观察者使用5分Likert量表对78张CBCT图像进行两次两次龋齿的存在和穿透深度评分，间隔2周。然后将牙齿切片并在立体显微镜(金标准)下观察。将四个方案相互比较，并与黄金标准进行比较。绘制受试者工作特性(ROC)曲线,计算曲线下面积（AUC），并通过卡方检验（α=0.05）进行比较。
结果：对于ULD-NORM，观察者之间的协议范围为0.5233至0.6034，0.5380到0.6279的NORM，0.5856至0.6300对于ULD-HR，和0.6614到0.7707的HR图像。ULD-HR的观察者内部协议范围为0.6027至0.8812，HR为0.7083至0.7556，ULD-NORM为0.6076至0.9452，和0.7012到0.9221的NORM图像。AUC比较显示NORM和ULD-NORM之间没有显着差异（P>0.05），或HR和ULD-HR(P>0.05)。最高的AUC属于HR（0.8529），最低的属于NORM（0.7774）。
结论：考虑到ULDCBCT中辐射剂量的显着降低及其对检测近端龋齿的可接受诊断准确性，该方案可用于检测近端龋损并评估其深度.
