Microstructural characterization of non-carious cervical lesions by en face optical coherence tomography

Non-carious cervical lesions (NCCL) are defned as the loss of tooth substance at the cemento-enamel junction. They are attributed to abrasion, erosion and/or eccentric occlusal overload. In order to evaluate the importance of occlusal factors in the etiology of NCCL, we investigated extracted frontal teeth by en face optical coherence tomography (eFOCT). Materials and methods. 35 frontal teeth, derived from patients with active bruxism and eccentric occlusal interferences, presented early NCCL on the labial surfaces. The other 5 frontal teeth had a normal crown morphology and were not exposed to occlusal overload before extraction. The dental samples were investigated using eFOCT operated in B-scan and C-scan mode. The eFOCT employs a low coherence source at 1300 nm. Results. Frontal teeth with normal crown morphology had a homogeneous microstructure of the cervical hard tissues on eFOCT images. The eFOCT investigation revealed a characteristic pattern of cracks in the area of NCCL of occlusal overloaded frontal teeth. Conclusions. eFOCT is an imaging technique that effectively identifes the microstructural effects of occlusal overload on the cervical hard tissues of frontal teeth.