The whole cycle of root canal treatment takes about half a month, during which the patient needs to visit the hospital about 3-4 times, with an interval of about 1 week between each visit. Root canal treatment is done by opening the pulp chamber and then sealing the pulp with a deactivating agent to avoid excessive pain during nerve extraction. After 1 week of sealing in the deactivator, you can visit the hospital for a follow-up visit, drill the cavity and rinse the mouth, then remove the nerve, then thoroughly clean the infected material for root canal preparation, then seal the root canal with a medication such as calcium hydroxide, and wait for about 1 week for a follow-up visit. If the root does not show any inflammatory reaction and the percussion pain has disappeared, normal root canal filling can be performed, and after the root canal filling is completed, consider whether a pile crown restoration is needed later.