自研全光纤光学相干计算机断层摄影术灵敏检测早期牙釉质龋

Detection of early enamel caries with a new self-developed all-fiber-OCT system

目的探索新型生物组织高分辨率成像技术——光学相干计算机断层摄影术(OCT)用于龋病早期诊断。方法选用化学酸蚀法在离体人恒牙釉质光滑面制备0、12、24、48、72、96、120h不同时间的早期脱矿人工龋模型,采用自行研发的口腔全光纤OCT(AF-OCT)进行离体人恒牙早期牙釉质人工龋的体外检测,并与同一牙齿样本的显微数码摄影、扫描电子显微镜和偏振光显微镜的检测结果进行比较,检验AF-OCT体外检测早期龋变的效能。结果AF-OCT可早期准确检测到脱矿12h以内的牙釉质表面组织学水平的改变,开窗区釉质表面脱矿深度与脱矿时间成正比。与3种常用体内外检测手段相比,AF-OCT可早于显微数码摄影观察到牙釉质表面的形貌改变,与扫描电子显微镜和偏振光显微镜检测结果高度相关。结论自研AF-OCT可早期、精确、无创地检测出脱矿12h以内的早期牙釉质表面人工龋变,并可实现量化测定和分析,获得的龋变深度量化测量数据与偏振光显微镜下组织学测量结果高度相关。

Objective To explore the new imaging technique of biological tissue-optical coherence tomography（OCT） for early diagnosis of dental caries. Methods A 2 mm × 3 mm experimental window in adamant slippery surfaces of permanent teeth was prepared, demineralized the enamel surface within the windows area to creat early stage of artificial caries mould, by aciding the window surface 0, 12, 24, 48, 72, 96, 120 hours with an pH 4.5 etching liquid in vitro. Detected the demineralized changes on the experimental window surface by a dental all-fiber-OCT（AF4）CT） system, which were new self developed and compared the test results with clinical digital photomicrography（DPM）, scanning electron microscope（SEM） and polarimicroscopy（PMS） on the same experimental window of same teeth sample, checkouted the sensitivity and efficacy of AF-OCT for early quantitative detection of artificial caries in vitro. Results The AF-OCT system accurately detected enamel demineralization as early as in 12 hours aciding stage, the results obtained by SEM was earlier than that by DPM with similar finding; The demineralized depth presented positive correlation to the aciding hours. It was shown that quantitative detection data by OCT had high correlation to those by PMS. Conclusion The self-developed AF-OCT system could accurately detect early artificial dental caries within 12 hours without invasion and can be achieved detection and analysis. The determination data of demineralized depth by AF-OCT have shown a high degree of correlation with those by PMS.