A tooth with percussion pain indicates the possibility of the following problems: 1. The affected tooth has the manifestation of periapical inflammation, which needs to be determined by taking x-rays. Periapical periodontitis occurs because the tooth has chronic pulpitis, which is not treated in a timely manner, and the inflammation invades outside the periapical area, resulting in resorption of the alveolar bone outside the periapical area and the formation of an abscess or granuloma in the apical area. At this time, if no treatment is carried out, the tooth will loosen and there is a risk that it needs to be extracted. 2, the tooth may have a hidden fracture, this situation is mainly when the patient can recall when recalling that he or she has bitten a hard object, the affected tooth is likely to have been in pain once before, at this time, it can be determined by CBCT whether the affected tooth can be retained. 3, occlusal trauma, the upper and lower bite because of the imbalance in the occlusal relationship, resulting in a certain tooth under excessive force Excessive bite trauma occurs, and the balance in the mouth can be adjusted through jaw adjustment.