The benefits of root canal treatment for 4-year-old children are to completely remove the inflammation of the milk teeth, to relieve the pain and swelling of the teeth, and to facilitate the development of the permanent tooth embryo, etc. It is recommended to have regular oral checkups, and to go to the hospital in time for treatment when there are any medical conditions. As 4 year old children are in the period of milk teeth, when the teeth have symptoms such as pulpitis and apical inflammation, root canal treatment can completely remove the inflammation of milk teeth and avoid the development of the disease. If a tooth is swollen and painful due to apical inflammation, a root canal can quickly relieve pain and reduce swelling. If a root canal is not done in time, the continued development of apical inflammation will attack the bone plate, which may affect the development of the permanent tooth embryo and may lead to abnormalities in the development of the permanent tooth embryo, which can be avoided due to the inflammation after timely treatment.