光学相干断层成像技术及其在窝沟龋检测中的应用

Optical coherence tomography and its application in the detection of occlusal caries

窝沟龋的早期发现和及时诊疗仍是口腔临床亟待解决的问题。光学相干断层成像技术(OCT)是一种新型非侵入性、高分辨率的光学诊断技术,可提供早期龋损的形态学和深度信息,且受釉质钙化不全及着色等因素影响较小。由于窝沟脱矿区域孔隙度增加,所以OCT利用低相干干涉原理在微孔中形成增强的微界面引起反射和多重散射,检测窝沟不同深度层面对入射低相干光的反射或背向散射信号,生成窝沟早期釉质龋及牙本质龋的二维或三维图像,通过计算集成反射率等进行龋损程度的量化分析,在窝沟龋诊断、抗龋治疗效果评估和辅助选择性清除脱矿牙体组织等方面具有良好的应用前景。本文着重就常规OCT、偏振敏感OCT、扫频OCT和交叉偏振OCT以及窝沟龋OCT成像与量化分析、OCT的窝沟龋诊断效能和OCT对窝沟龋疗效监测等研究进展作一综述。

The early detection and diagnosis of caries in pits and fissures remain major problems in clinical dentistry. Optical coherence tomography（OCT） is an emerging, non-invasive, high-resolution, optical diagnostic technique. This approach can provide information on morphology and depth of early caries without the interference of enamel hypocalcification and stain. As the porosity of demineralized dental tissue increases, micro-interfaces within the micropores augment reflection and multiple scattering. Based on low-coherence interferometry, OCT can detect the reflected or backscattered signals to the incident beam at various vertical extents. OCT can also generate 2D/3D images of early enamel caries and dentine caries on the occlusal surface, and quantify lesion severity by calculating the integrated reflectivity. OCT is a promising prospect for the diagnosis of occlusal caries, anti-caries efficacy estimation, and assistance in the selective removal of demineralized tooth tissue by laser. This review focuses mainly on different types of OCT, namely, the conventional, polarization-sensitive, swept-source, and cross-polarization OCT. This review also highlights the abovementioned OCT applications in imaging and quantitative analysis, diagnostic efficiency, and therapeutic monitoring of occlusal caries.