1. Department of Cariology and Operative Dentistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan;2. 81‐3‐5803‐548381‐3‐5803‐0195;3. Clinical Oral Science, Department of Oral Health Care Sciences, Faculty of Dentistry, Tokyo Medical and Dental University, Tokyo, Japan;4. International Exchange Center, Tokyo Medical and Dental University, Tokyo, Japan;5. Division of Oral and Dental Surgery, Department of Advanced Medicine, National Hospital for Geriatric Medicine, National Center for Geriatrics and Gerontology, Obu, Aichi, Japan
Abstract:
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.
