Optical diagnosis method for dental pulp viability based on the blood oxygen saturation using short wavelength LED

牙髓活力的评估是牙科治疗的重要诊断步骤。由于血管供应是评估牙髓活力的最准确的决定因素，我们开发了525 nm LED的透射式血流图(TLP)系统来检测牙髓组织的微循环变化。在这项研究中，我们主要关注牙髓血氧水平(SO2)作为牙髓活力的补充信息与牙髓炎症的关系，并试图通过体外研究建立基础理论。将充氧和除氧后的人血循环通过提取的人上门牙，以模拟牙齿体积图。为了计算SO2，用峰值发射波长分别为470 nm、525 nm和590 nm的三个发光二极管测量了脉冲波的幅度(V&lt；p-p&gt；)和透射光强度(Vt)。结果表明，由470和590 nm、525和590 nm计算的φ比值(ln(V&lt；p-p&gt；/Vt))与实际SO2呈线性关系。

Assessment for the dental pulp vitality is a crucial diagnostic procedure for the dental treatment. As the vascular supply is the most accurate determinant for assessing pulp vitality, we have developed the Transmitted-light Plethysmography(TLP) system with 525nm LED to detect microcirculatory changes in the pulp tissues. In this study, we focused on the pulpal blood oxygen levels(SO_2) as additional information for pulp viability in relation to pulpal inflammation, and attempted to establish the basic theory by in vitro study. The oxygenated and deoxygenated human blood was circulated through the extracted human upper incisors to simulate the tooth plethysmogram. For computation of SO_2, the amplitudes of pulse waves(V_<p-p>) and transmitted light intensity(V_t) were measured using three LEDs with peak emission wavelength at 470nm, 525nm and 590nm. Results indicated ratio ofφ(ln(V_<p-p>/V_t)) computed by 470 and 590nm, 525 and 590nm showed linear relationship with actual SO_2.