Acute periapicalitis is clinically characterized by severe pain and complete lack of contact between the upper and lower teeth, while chronic periapicalitis does not have this feature. Acute periapicalitis is characterized by severe pain in the affected tooth root and bone if the upper and lower teeth touch. The treatment plan for acute periapical periodontitis is mainly root canal therapy, as follows: 1. immediately drill the tooth to release the inflammatory media inside; 2. give antibiotics, give anti-inflammatory drugs, such as cephalosporin plus metronidazole oral or amoxicillin plus metronidazole oral, provided that the patient’s history of drug allergies and alcohol consumption is clear to determine whether these drugs can be used. In addition, for patients with acute periapical periodontitis, the affected tooth can be ground a little shorter, which can quickly solve the pain, but the disadvantage is that it may damage the tooth, depending on the patient to decide, if the patient can accept to grind the tooth a little, then this method can be used; if the patient is not willing to grind the tooth, then do not need to take this option, mainly to root canal treatment and drug The main treatment is root canal and medication.