Pulpitis is a condition that arises from the further progression of dental caries, which is a defect in the hard tissues of a tooth caused by bacterial infection. If the caries is not treated in time to stop its further progression, bacteria will further infect and cause inflammation of the dental nerve, also known as the pulp tissue. The innermost part of a tooth contains the dental nerve, surrounded by hard dental bone and dentin. Therefore, once the dental nerve becomes inflamed, the pain can be very severe. However, pulpitis can improve after root canal treatment, meaning it is curable, but it requires root canal treatment of the tooth. If not treated promptly, it will not heal on its own. If pulpitis is not treated in time, it can further progress to form periapical abscess, and in severe cases, it can cause facial swelling.