Wedge defect is often diagnosed as a clinical defect between the tooth and the gum, and in most cases it cannot heal itself. Wedge-shaped defects occur mainly in the cervical region of the tooth and are a symptom of the loss of enamel and dentin close to the gingival area. The structure at the enamel-dentin boundary of the cervical part of the tooth is inherently weak and easily worn away, and if there is a bad habit of vigorous lateral brushing, it can make the wedge-shaped defect more likely to appear. In addition to the above reasons, dental hard tissue stress fatigue, acidic oral environment and other reasons can lead to the emergence of wedge-shaped defects, or even more serious. When wedge-shaped defects appear, the first and most important thing is to correct the bad brushing habits and change from horizontal to vertical brushing. In addition, it is recommended that wedge-shaped defects should be actively repaired, and if the defect causes pulpitis or periapical inflammation, root canal nerve treatment is required before crown set restoration.