Gaêta-Araujo Hugo, Oliveira-Santos Nicolly, de Oliveira Reis Larissa, Nascimento Eduarda Helena Leandro, Oliveira-Santos Christiano
Oral Radiology Section, School of Dentistry, Federal University of Alfenas (UNIFAL-MG), Rua Gabriel Monteiro da Silva, 700, Alfenas, MG, 37130-000, Brazil.
Department of Oral Diagnosis, Piracicaba Dental School, University of Campinas (UNICAMP), Piracicaba, SP, Brazil.
Oral Radiol. 2023 Jan;39(1):53-58. doi: 10.1007/s11282-022-00599-x. Epub 2022 Feb 26.
To evaluate whether the automatic exposure compensation in the presence of high-density materials can affect the measurement of alveolar bone level.
Thirty regions of seven dry skulls and six mandibles were radiographed with and without a high-density material, using two digital radiographic technologies: photostimulable phosphor plate (PSP, Digora Optime) and sensor (CMOS, Digora Toto), totaling 120 images. The distances from the cement-enamel junction to the alveolar bone crest were measured using cone-beam computed tomography (CBCT) images to represent the reference standard. The same measurements of alveolar bone level and the average of the pixel values of the image were evaluated on the radiographs. Paired t test compared the average pixel values and alveolar bone-level measurements between images with and without high-density material. One-way analysis of variance compared the difference between radiographic and CBCT measurements (α = 0.05).
The high-density material reduced the pixel values in PSP (p = 0.002) and CMOS (p < 0.001) technologies, demonstrating the AEC functioning in both technologies. There was no difference in bone-level measurements between the images without and with the high-density material for both technologies (p ≥ 0.091), or between the tomographic and radiographic measurements (p ≥ 0.319).
In the presence of high-density material, the automatic exposure compensation reduces the average pixel values of the images (i.e., images get darker), but does not influence the radiographic measurements of alveolar bone level.
评估在存在高密度材料的情况下自动曝光补偿是否会影响牙槽骨水平的测量。
使用两种数字放射成像技术，即光激励荧光板（PSP，Digora Optime）和传感器（CMOS，Digora Toto），对七个干燥颅骨和六个下颌骨的30个区域进行有或没有高密度材料的X线摄影，共获得120张图像。使用锥形束计算机断层扫描（CBCT）图像测量从牙骨质-釉质界到牙槽嵴顶的距离，以此作为参考标准。在X线片上评估牙槽骨水平的相同测量值以及图像像素值的平均值。配对t检验比较有无高密度材料的图像之间的平均像素值和牙槽骨水平测量值。单因素方差分析比较放射成像测量值与CBCT测量值之间的差异（α = 0.05）。
高密度材料降低了PSP（p = 0.002）和CMOS（p < 0.001）技术中的像素值，表明两种技术中的自动曝光补偿均起作用。对于两种技术，有无高密度材料的图像之间的骨水平测量值没有差异（p≥0.091），断层扫描测量值与放射成像测量值之间也没有差异（p≥0.319）。
在存在高密度材料的情况下，自动曝光补偿会降低图像的平均像素值（即图像变暗），但不会影响牙槽骨水平的放射成像测量。
