It is often said that “toothache is not a disease, but a pain that kills”, and some of them have a bag on the gums, which means they are suffering from pulpitis or periapical inflammation, the main reason for pulpitis and periapical inflammation is that the deep cavities are not treated in time and the bacteria invade the pulp, which leads to inflammation. The main manifestation is spontaneous paroxysmal pain, hot and cold stimulation induces or aggravates the pain, the pain is more serious at night than during the day, the pain cannot be localized, the patient cannot point out the tooth pain, if not treated in time, after the pain is relieved, one or several bags will bulge in the corresponding gum area, which has developed into periapical inflammation. The effective way to prevent pulpitis and periapical inflammation is to prevent caries and control the development of caries, once it develops to pulpitis or periapical inflammation, thorough root canal treatment is necessary, because pulpitis and periapical inflammation are bacterial infectious diseases, so the key to treatment is to eliminate the inflammation and then tightly fill the root canal, eliminate the dead cavity and stop reinfection. The most common treatment methods are dry pulp therapy, plastination therapy, and root canal therapy, the first two of which are largely unused due to their poor long-term efficacy after treatment, while root canal therapy is widely used in clinical practice due to its efficacy.