The innermost toothache is caused by the following reasons: 1, pericoronal abscess. During the process of tooth eruption, blind pocket is produced, and the long-term embedded food in the blind pocket is easy to produce acid and pus, which will produce the phenomenon of tooth pain. 2, tooth decay. In general, deep caries will have the pain of food embedment, so it will also produce the phenomenon of toothache. 3.Pulpitis. When deep caries develops to pulpitis, there will be severe pain, with spontaneous pain, night pain, and it will be accompanied with half of the face pain. 4.Periapical abscess. When the tooth decay is serious, it may produce periapical abscess of the tooth, which will produce a jumping pain. 5.Tooth splitting. When the tooth is split, it will produce chewing pain, or it is easy to have abscess, it should be examined by specific film and specific examination in the mouth to determine the cause of tooth pain, and make specific treatment according to the cause of tooth pain. If it is a wisdom tooth, you can choose to extract it, and if it is another tooth, you can choose to restore it. If the split pulp is beyond repair, you can choose to extract the tooth and then observe it for about three months before restoring it.