Objective To investigate the association of the dental wedge-shaped defect（non- carious cervical lesion）with its abrasion in Chinese 1 839 premolars. Methods To observe the morphology of non-carious cervical lesions and the situation of abrasion on the occlusal surface. The depth and width of cervical lesions were measured. Results Wedge-shaped defect was found in 644 premolars and the incidence was 35.02%. There was significant difference in incidence of lesion among different kinds of premolars（P
