Significance: It is not sufficient to detect caries lesions on tooth surfaces; it is also necessary to measure the activity of the lesions to determine if intervention is needed. Changes in the reflectivity of lesion areas during dehydration with forced air at short wavelength infrared (SWIR) wavelengths can be used to assess lesion activity since these changes represent the evaporation dynamics of water from the lesion. Aim: The aim of this study is to develop new optical methods for assessing lesion activity on tooth surfaces utilizing the strong water absorption band near 1950-nm. Approach: The time-resolved reflectivity of 20 active and arrested caries lesions on the surfaces of human extracted teeth was monitored at 1300 to 2000 nm using broadband light sources and an extended range InGaAs camera during drying with air. Results: Multiple parameters representing the rate of change of the lesion reflectivity correlated with the presence of a highly mineralized outer surface zone indicative of lesion arrest measured with x-ray microtomography (microCT). Performance at 1950-nm was higher than for other wavelengths. Conclusions: This study demonstrates that SWIR imaging near 1950-nm has great potential for the assessment of lesion activity.

中文翻译：

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用于龋病诊断的 1950 nm 吸水带附近的动态 SWIR 成像

意义：仅检测牙齿表面的龋齿病变是不够的；还需要测量病变的活动性以确定是否需要干预。在短波红外 (SWIR) 波长强制空气脱水期间病变区域反射率的变化可用于评估病变活动，因为这些变化代表水从病变中的蒸发动力学。目的：本研究的目的是开发新的光学方法，利用 1950 nm 附近的强吸水带评估牙齿表面的病变活动。方法：在空气干燥过程中，使用宽带光源和扩展范围的 InGaAs 相机在 1300 至 2000 nm 范围内监测人类拔牙表面 20 个活动和停止的龋齿病变的时间分辨反射率。结果：代表病变反射率变化率的多个参数与高度矿化外表面区域的存在相关，该区域指示用 X 射线显微断层扫描 (microCT) 测量的病变停滞。1950 nm 处的性能高于其他波长。结论：本研究表明，1950 nm 附近的 SWIR 成像具有评估病变活动的巨大潜力。