A child with a decayed tooth with no inflammation of the nerve can have a direct filling without a root canal. In the early stage of tooth decay, the bacterial infection has not reached the nerve of the tooth, you can directly remove the decayed part, and then fill the tooth without root canal treatment. If the nerve of the tooth is infected and there is spontaneous pain, pain at night while sleeping, or swelling of the face, these cases cannot be completed in one filling and require nerve treatment, also known as root canal therapy. Root canals should be performed during the root stabilization phase of the tooth, which is first determined by a radiograph. Therefore, the child has a cavity without pain, depending on the degree of tooth decay pulp there is no inflammation, not always need root canal treatment, you can go to the dentist to check.