Wada Ikumi, Shimada Yasushi, Ikeda Masaomi, Sadr Alireza, Nakashima Syozi, Tagami Junji, Sumi Yasunori
Department of Cariology and Operative Dentistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan.
Clinical Oral Science, Department of Oral Health Care Sciences, Faculty of Dentistry, Tokyo Medical and Dental University, Tokyo, Japan.
J Biophotonics. 2015 Oct;8(10):846-54. doi: 10.1002/jbio.201400113. Epub 2014 Dec 11.
Non-carious cervical lesions (NCCLs) involve various forms of tooth loss with different etiologies. This study aimed to utilize swept-source optical coherence tomography (SS-OCT) at 1300 nm wavelength range in vitro and in vivo to evaluate and clarify the mechanism of NCCLs. In the in vitro phase, a dentin attenuation coefficient (μt ) derived from the SS-OCT signal at NCCL was compared with mineral loss obtained from transverse microradiography (TMR) to determine a μt threshold to discriminate demineralization of cervical dentin in vivo. In the clinical study, 242 buccal surfaces were investigated in 35 subjects. Presence and dimensions of NCCLs, cervical cracking and the degree of demineralization at the exposed cervical dentin were determined using SS-OCT. Dentin demineralization was observed in 69% of NCCLs. SS-OCT results confirm that dentin mineral loss and occlusal attrition were associated with larger NCCLs, and can be considered as an etiological factor in formation and progress of these lesions. (A) We determined the attenuation coeffcient (μt ) threshold of SS-OCT signal for the detection of demineralization (1.21) from in vitro study. DEM: demineralized dentin, sound: sound dentin. (B) Using the μt threshold, we observed NCCLs in vivo to detect the demineralization in cervical dentin. SS-OCT scanning was performed along the red line. (C) SS-OCT image obtained along the red line in B. In SS-OCT, brightness of dentin beneath the NCCL was increased (arrow) compared with intact zone. The cervical dentin was slightly demineralized (μt : 1.25). e: enamel, d: dentin, g: gingiva.
非龋性颈部病变（NCCLs）涉及多种不同病因导致的牙齿缺失形式。本研究旨在利用波长范围为1300nm的扫频光学相干断层扫描（SS-OCT）技术，在体外和体内评估并阐明NCCLs的发病机制。在体外阶段，将NCCL处SS-OCT信号得出的牙本质衰减系数（μt）与横向显微放射照相（TMR）获得的矿物质流失进行比较，以确定一个μt阈值，用于区分体内颈部牙本质的脱矿情况。在临床研究中，对35名受试者的242个颊面进行了调查。使用SS-OCT确定NCCLs的存在和尺寸、颈部裂纹以及暴露的颈部牙本质的脱矿程度。在69%的NCCLs中观察到牙本质脱矿。SS-OCT结果证实，牙本质矿物质流失和咬合磨损与较大的NCCLs相关，可被视为这些病变形成和发展的一个病因。（A）我们从体外研究中确定了用于检测脱矿的SS-OCT信号衰减系数（μt）阈值（1.21）。DEM：脱矿牙本质，sound：健康牙本质。（B）使用μt阈值，我们在体内观察NCCLs以检测颈部牙本质的脱矿情况。沿红线进行SS-OCT扫描。（C）沿B中红线获得的SS-OCT图像。在SS-OCT中，与完整区域相比，NCCL下方牙本质的亮度增加（箭头）。颈部牙本质轻度脱矿（μt：1.25）。e：釉质，d：牙本质，g：牙龈。
