Toothache is caused by inflammation of the pulp nerve and a large amount of inflammatory exudate increases. The tooth is a hard secret tissue and when the pressure inside the pulp chamber increases it will cause severe pain in the tooth. Applying an ice pack is the principle of thermal expansion and cold contraction, which means that hot pain and cold relief reduces the pressure in the pulp cavity and slows down the swelling of the pulp, which will reduce the pressure in the pulp cavity and make it relieve the pain. However, this method is only applicable to patients with acute pyogenic pulpitis and cannot cure the disease of pulpitis, so it is recommended that patients be able to go to the regular hospital stomatology department in time to identify the cause and treat the disease. In the case of pulpitis, conventional root canal treatment is needed to completely solve the tooth pain problem.