To treat cavities in children, first, the extent of tooth decay needs to be assessed. If the decay is mild, the decayed part can be removed and directly filled. If the decay is severe enough to inflame the dental nerve, an X-ray of the tooth is required. If it is a deciduous tooth that is about to fall out soon and is not worth saving, treatment might be unnecessary. However, if the tooth root has not been absorbed and the permanent tooth will take a long time to erupt, root canal treatment can be considered. In cases where a young permanent molar is decayed and the nerve is infected, a vital pulpotomy should be performed to preserve the living pulp and promote further development of the tooth root.