The flesh inside the tooth cavity is mainly divided into 3 kinds of cases, as follows: 1. The tooth cavity mainly occurs in the place where two teeth are adjacent to each other, that is, the caries occurs in the adjacent jaw surface, and the patient does not consult the doctor in time, which causes the gum at the connection of the cavity to grow into the cavity. At this time, the affected tooth may have larger and deeper cavity, but the symptom of nerve pain has not yet occurred, and the tooth can be filled after removing the gingival growth; 2, the affected tooth mostly has larger cavity, and the cavity has involved the dental nerve, and the larger perforated nerve hole can be detected, which is formed by the dental nerve growth protruding from the cavity, and there is pain and bleeding on probing, which mostly occurs in the young affected tooth, and there are symptoms of not daring to bite with the affected tooth or having pain and bleeding on biting, but The bottom of the pulp cavity of the affected tooth is intact. In this case, root canal treatment is feasible for teeth with completed root development, and permanent crown restoration treatment will be performed after adulthood. If the tooth has not completed root development, it is necessary to perform apical induction molding after nerve extraction to induce its root to continue to develop and complete before root canal treatment; 3, most of the affected teeth are decayed and missing, only the remaining remnant crown and remnant root, and the decay has involved the pulp base, resulting in the periodontal membrane in the root bifurcation area to grow and protrude into the pulp cavity and form. The affected tooth is mostly painless, but the retention rate of the affected tooth is relatively low, and most of the affected teeth need to be extracted for treatment.