Le Michael H, Darling Cynthia L, Fried Daniel
Department of Preventive and Restorative Dental Sciences, University of California, San Francisco, San Francisco, California 94143-0758, USA.
Lasers Surg Med. 2010 Jan;42(1):62-8. doi: 10.1002/lsm.20862.
Several studies have demonstrated that polarization sensitive optical coherence tomography (PS-OCT) can be used to nondestructively measure the severity of subsurface demineralization in enamel and dentin, track lesion progression over time and measure remineralization. The purpose of this study was to develop methods for the automated assessment of the depth and severity of demineralization in PS-OCT scans.
Subsurface caries-like lesions of increasing depth and severity were produced in adjoining windows on 10 bovine enamel samples via exposure to demineralization for periods of 1-4 days. PS-OCT scans were acquired for each sample and analyzed using various methods to calculate the lesion depth and severity. Edge detection algorithms were most successful for measurement of the lesion depth for improved assessment of lesion severity.
Edge-finding algorithms were able to detect significant differences (P<0.05) in the lesion depth and severity between each of the periods of demineralization and sound enamel. The lesion depth and mineral loss were also measured with polarized light microscopy and transverse microradiography after sectioning the teeth for comparison.
This study demonstrates that the depth and severity of early lesions can be calculated automatically for rapid analysis of PS-OCT images.
多项研究表明，偏振敏感光学相干断层扫描（PS-OCT）可用于无损测量牙釉质和牙本质中表面下脱矿的严重程度，追踪病变随时间的进展情况以及测量再矿化程度。本研究的目的是开发用于自动评估PS-OCT扫描中脱矿深度和严重程度的方法。
通过将10个牛牙釉质样本暴露于脱矿环境1 - 4天，在相邻窗口产生深度和严重程度不断增加的类似龋齿的表面下病变。对每个样本进行PS-OCT扫描，并使用各种方法进行分析以计算病变深度和严重程度。边缘检测算法在测量病变深度方面最为成功，有助于更好地评估病变严重程度。
边缘检测算法能够检测出脱矿各阶段与健康牙釉质之间在病变深度和严重程度上的显著差异（P<0.05）。在将牙齿切片后，还使用偏光显微镜和横向显微放射摄影测量了病变深度和矿物质流失情况以作比较。
本研究表明，可以自动计算早期病变的深度和严重程度，以便快速分析PS-OCT图像。
