Whether or not a longitudinal fracture of the second molar can be repaired depends on the extent of the fracture. If the crack is small, it can be restored. If the tooth is so severely cracked that it has no value for preservation, it can be restored after extraction. Small cracks or defects that do not involve the pulp of the tooth can be repaired by carefully removing the cracks and filling them directly to repair the shape of the tooth; if the cracks are deeper or the pulp is injured, crown restoration can be carried out after endodontic treatment; for longitudinal cracks that have no value for retention, surgical removal can be carried out as early as possible, and implantation can be carried out to restore the tooth. After the second molar tooth is cracked, it can not be restored to its full form by itself, so it should be treated as soon as possible under the guidance of a professional doctor. In daily life, maintain good oral hygiene, reduce the intake of carbonated beverages, avoid tooth decay and caries, and prevent cracked teeth.