Dose optimisation has been revisited in the literature due to the frequent use of cone beam computed tomography (CBCT). Although the reduction of the field-of-view (FOV) size has shown to be an effective strategy, this indirectly increases the negative effect from the exomass. The aim of this study was to evaluate the diagnostic accuracy of an optimised CBCT protocol in the detection of simulated vertical root fracture (VRF) in the presence of metal in the exomass and/or inside the FOV. Twenty teeth were endodontically instrumented and VRF was induced in half of them. All teeth were individually placed in a human mandible covered with a soft tissue equivalent material, metallic materials were placed at different dispositions in the exomass and/or endomass, and CBCT scans were obtained at two dose protocols: standard and optimised. Five radiologists evaluated the images and indicated the presence of VRF using a 5-point scale. Area under the ROC curve (AUC), sensitivity, and specificity were calculated and compared using ANOVA (α = 0.05). Overall, AUC, sensitivity, and specificity did not differ significantly (p > 0.05) between the dose protocols. In conclusion, optimised dose protocols should be considered in the detection of simulated VRF irrespective of the occurrence of artefacts from metallic materials in the exomass and/or inside the FOV.

由于锥形束计算机断层扫描 (CBCT) 的频繁使用，文献中重新讨论了剂量优化。尽管减小视野 (FOV) 大小已被证明是一种有效的策略，但这间接增加了外质量的负面影响。本研究的目的是评估优化的 CBCT 协议在检测模拟垂直根折 (VRF) 时的诊断准确性，该方案在外体和/或 FOV 内部存在金属。对 20 颗牙齿进行了牙髓治疗，其中一半进行了 VRF 诱导。所有牙齿都单独放置在覆盖有软组织等效材料的人类下颌骨中，金属材料放置在外肿块和/或内肿块中的不同位置，并以两种剂量方案获得 CBCT 扫描：标准和优化。五位放射科医生评估了图像，并使用 5 分制表示存在 VRF。ROC 曲线下面积 (AUC)、敏感性和特异性使用方差分析 (α = 0.05) 计算和比较。总体而言，不同剂量方案之间的 AUC、敏感性和特异性没有显着差异（p > 0.05）。总之，在检测模拟 VRF 时应考虑优化剂量方案，而不管外体和/或 FOV 内部是否出现金属材料的人工制品。