Symptoms of dental defects are related to the scope and extent of the defects and the number of defects in the dentition, as follows: 1. Dental and pulp symptoms: if the dental defects are shallow, the symptoms are not obvious; if the dental defects involve dentin or pulp, pulp irritation can occur, and even pulp inflammation, pulp necrosis and periapical lesions; 2. Periodontal symptoms: if the defects occur in the neighboring surfaces of the dentition, they can damage the normal teeth and cause food impaction, which in turn may cause inflammation of local periodontal tissues and even tilt and displacement of neighboring teeth, resulting in abnormal occlusal relationships. 2, periodontal symptoms: if the defect occurs in the adjacent surface of the tooth, it can destroy the normal teeth’s adjacency, lead to food blockage, and then cause inflammation of the local periodontal tissues, and even tilt and shift of the adjacent teeth, resulting in abnormal occlusal relationship. If the defect occurs in the axial surface, it can damage the normal axial surface and lead to inflammation of the gingiva; 3. Occlusal symptoms: If the defect is large in size, it will not only affect the chewing efficiency, but also form the bad habit of chewing on the side, which will lead to the occurrence of the disorder of the oro-mandibular system in a serious case; 4. If the defect occurs in the anterior teeth, it can affect the appearance and pronunciation of the patient, and even affect the patient’s psychological state.