Toothache containing cool water overnight has a certain effect on the pain caused by acute pulpitis, but only to relieve the pain, there is no therapeutic effect. The cause of the toothache must be clearly identified in order to effectively stop the pain. In addition to acute pulpitis other than the case of containing cool water is useless, and may aggravate the irritating pain. 1. Acute pulpitis caused by: part of the acute pulpitis after pus, there will be a characteristic performance that hot pain cold pain. This kind of patients appear after the night spontaneous pain, by containing cool water can relieve the pain. However, when the temperature of the oral cavity rises, the toothache will reappear, which is why they hold cool water overnight. The effective treatment for acute pulpitis is root canal therapy. Caries-induced: Toothache caused by dental caries requires removal of the decayed tissue, and if there is no pulp leakage, surgical treatments such as resin filling and inlay restoration can be taken. If there is no pulp leakage, surgical treatments such as resin filling and inlay restoration can be taken. If there is pulp leakage, root canal treatment and then filling treatment will be needed. 2. Periodontitis: toothache caused by periodontitis requires periodontal treatment, such as supragingival cleaning, subgingival scraping, etc. Surgical treatments such as flap surgery and bone grafting are available when necessary. 3. Apical periodontitis: apical periodontitis can appear toothache, need to carry out root canal treatment, at the same time, patients can follow the doctor’s instructions to take ibuprofen, metronidazole and other anti-inflammatory pain, surgical treatment including apicoectomy, tooth extraction, and so on. Toothache may also have other causes, it is recommended to go to the hospital in a timely manner to clarify the cause of the disease, according to the cause of the appropriate treatment. The application of drugs need to strictly follow the doctor’s instructions.