Oliveira Matheus Lima, Vieira Marcela Lacerda, Cruz Adriana Dibo, Bóscolo Frab Norberto, DE Almeida Solange Maria
Department of Oral Diagnosis, Piracicaba Dental School, UNICAMP - University of Campinas, Campinas, SP, Brazil.
Braz Dent J. 2012;23(6):703-6. doi: 10.1590/s0103-64402012000600013.
The aim of this study was to assess the applicability of gray scale inversion in performing digital linear endodontic measurements. Standardized digital images were taken of 40 extracted human permanent single-rooted teeth with K-files size 15 placed at different lengths in the root canal, using the CDR Wireless(®) digital system. All images were treated with Positive, a digital tool that inverts the grayscale value. Eight radiologists measured the distance between the lower limit of the rubber stop and the tip of the file on both original and positive images. After 15 days, they repeated this procedure in 50% of the image samples. The intra- and inter-examiner agreement was analyzed by intraclass correlation test, and the comparison between the two image groups and the actual lengths by the Student's t-test (α=0.05). Intra- and inter-examiner evaluation showed high reproducibility (r>0.95) of both original and positive images. No statistically significant differences (p>0.05) were found between measurements performed on original and positive images, but both differed significantly from the actual lengths (p<0.05). Gray scale inversion has low applicability in measuring endodontic files, since it did not improve the accuracy of measurements.
本研究的目的是评估灰度反转在进行数字化根管长度测量中的适用性。使用CDR Wireless(®)数字系统，对40颗拔除的人类恒牙单根牙拍摄标准化数字图像，根管内放置不同长度的15号K锉。所有图像均使用Positive进行处理，Positive是一种可反转灰度值的数字工具。八位放射科医生在原始图像和经过处理的图像上测量橡胶止动器下限与锉尖之间的距离。15天后，他们在50%的图像样本中重复此操作。通过组内相关检验分析检查者内和检查者间的一致性，并通过学生t检验（α = 0.05）比较两组图像与实际长度之间的差异。检查者内和检查者间评估显示原始图像和经过处理的图像均具有高重复性（r > 0.95）。在原始图像和经过处理的图像上进行的测量之间未发现统计学上的显著差异（p > 0.05），但两者与实际长度均有显著差异（p < 0.05）。灰度反转在测量根管锉方面适用性较低，因为它并未提高测量的准确性。
