Pulpitis is a severe pain caused by bacterial infection of the pulp tissue, also known as the tooth nerve. The clinical symptoms of pulpitis are very severe, especially severe secondary pain, irritative pain, as well as indirect pain and pain that cannot be localized. Pulpitis results from the further development of dental caries. In the early stages of bacterial infection, if the carious decay of the tooth's hard tissue is not promptly filled, and if the progression of the caries is not timely halted, bacteria will further infect and cause inflammation of the tooth nerve, leading to pulpitis. This condition requires root canal treatment to alleviate the symptoms. Otherwise, the inflammation will further accumulate around the root apex, causing severe apical periodontitis and even leading to space infection or facial swelling.