Department of Dental Materials and Prosthodontics, Ribeirão Preto School of Dentistry, University of São Paulo, 14040-904, São Paulo, Brazil.
Department of Dentistry and Oral Health, Aarhus University, 8000 Aarhus, Denmark.
Dentomaxillofac Radiol. 2024 Apr 29;53(4):233-239. doi: 10.1093/dmfr/twae008.
This study evaluated the effect of metal artefact reduction (MAR) level and tube current on the assessment of dental implant positioning relative to the mandibular canal (MC) through cone-beam computed tomography (CBCT).
Titanium dental implants were placed in dried mandibles at 0.5-mm superior to the MC (group 1/n = 8) and 0.5-mm inside the MC with perforation of the cortex (group 2/n = 10). CBCT scans were obtained with different levels of MAR (off, medium, and high) and 2 tube currents (4 and 8 mA). Four examiners analysed the images and scored the contact between the implant and the MC using a 5-point scale. Sensitivity, specificity, area under receiver operating characteristic curve (ROC), and frequency of scores were calculated. Data were compared with analysis of variance 2-way and Tukey's test and scores with Chi-square test.
Specificity and area under ROC curve decreased significantly when MAR level was high compared with MAR-medium and MAR-off. The frequency of score 3 (inconclusive) was the highest, and scores 1 and 5 (definitely no contact and definitely contact, respectively) were the lowest with MAR-high, regardless of the tube current. When MAR was off, there were higher frequencies of scores 1 and 5.
The level of MAR influences the assessment of the relationship between the dental implant and the MC. MAR-high led to lower diagnostic accuracy compared with MAR-medium and off.
This article shows that high level of MAR can interfere in the diagnostic of dental implant positioning relative to the MC, decreasing its accuracy.
本研究通过锥形束计算机断层扫描（CBCT）评估金属伪影降低（MAR）水平和管电流对评估种植体相对于下颌管（MC）位置的影响。
将钛牙种植体放置在 MC 上方 0.5mm（第 1 组，n=8）和 MC 内 0.5mm 处（第 2 组，n=10），种植体穿透皮质。使用不同 MAR 水平（关闭、中、高）和 2 个管电流（4 和 8mA）获取 CBCT 扫描。4 名检查者使用 5 分制评估图像，并评估种植体与 MC 之间的接触情况。计算灵敏度、特异性、受试者工作特征曲线（ROC）下面积和评分频率。采用方差分析 2 路和 Tukey 检验进行数据比较，采用卡方检验进行评分比较。
与 MAR 中相比，MAR 高时特异性和 ROC 曲线下面积显著降低。MAR 高时，评分 3（不确定）的频率最高，评分 1 和 5（无接触和肯定接触）的频率最低，无论管电流如何。当 MAR 关闭时，评分 1 和 5 的频率更高。
MAR 水平会影响评估种植体与 MC 之间的关系。与 MAR 中相比，MAR 高会降低诊断准确性。
本文表明，高 MAR 水平会干扰种植体相对于 MC 位置的诊断，降低其准确性。
