Kuusisto N, Vallittu P K, Lassila L V J, Huumonen S
1 Department of Oral Pathology and Radiology, Institute of Dentistry, University of Turku, Turku, Finland.
Dentomaxillofac Radiol. 2015;44(2):20140157. doi: 10.1259/dmfr.20140157. Epub 2014 Oct 6.
The aim was to compare the intensity of artefacts in CBCT images caused by different percentages of radio-opacifying material in composite simulation models of implants. Titanium and zirconia models of implants were used as a reference for the evaluation of the intensity of artefacts.
Seven different percentages of radio-opacifying BaAlSiO2 fillers were added to composite resin to fabricate seven step wedges and simulation models of implants. Titanium and zirconia simulation models of implants were also fabricated. Aluminium step wedge was used as a reference for the measurement of grey values in intraoral radiographs. Step wedges were exposed with a Planmeca Intra X-ray machine (Planmeca Oy, Helsinki, Finland). All composite, titanium and zirconia simulation models of implants were exposed with a SCANORA(®) 3D dental X-ray machine (Soredex, Tuusula, Finland). Images and grey values were analysed with ImageJ software (National Institutes of Health, Bethesda, MD). To demonstrate possible artefacts between all the simulation models of implants, the images were also visually compared with each other using ImageJ software.
Artefacts were clearly present in CBCT images caused by titanium and zirconia and when the composite material consisted at least 20% BaAlSiO2. The intensity of artefacts increased when the radio-opacity of the composite material increased.
Materials containing less radio-opacity produce less pronounced artefacts. The cut-off point for artefacts is at 20% radio-opaque filling material in composite material.
本研究旨在比较种植体复合模拟模型中不同百分比的射线阻射材料在锥形束计算机断层扫描（CBCT）图像中产生的伪影强度。以钛和氧化锆种植体模型作为评估伪影强度的参考。
向复合树脂中添加七种不同百分比的射线阻射性BaAlSiO2填料，制作七个阶梯楔形物和种植体模拟模型。还制作了钛和氧化锆种植体模拟模型。铝阶梯楔形物用作口腔内X线片灰度值测量的参考。使用普兰梅卡Intra X射线机（芬兰赫尔辛基普兰梅卡公司）对阶梯楔形物进行曝光。所有复合、钛和氧化锆种植体模拟模型均使用SCANORA(®) 3D牙科X射线机（芬兰图苏拉索雷德克斯公司）进行曝光。使用ImageJ软件（美国国立卫生研究院，马里兰州贝塞斯达）分析图像和灰度值。为了展示所有种植体模拟模型之间可能存在的伪影，还使用ImageJ软件对图像进行了相互视觉比较。
钛和氧化锆以及当复合材料中至少含有20% BaAlSiO2时，CBCT图像中明显存在伪影。随着复合材料射线阻射性的增加，伪影强度增加。
射线阻射性较低的材料产生的伪影不那么明显。复合材料中射线阻射性填充材料的截止点为20%。
