The first molar pain should be determined according to the nature of the pain to determine the specific disease, and then determine the formal treatment means. If the pain is different, the disease type is also different, if it is caused by the caries of medium degree caries, it often shows that it is painful to eat sweet food, deep caries shows that it is cold and hot one-off irritation pain, the pain symptom disappears when the stimulus is removed, there is no spontaneous pain, generally when the caries is found filling treatment can be. When pulpitis occurs, there will be spontaneous pain, cold and hot irritation pain is intense and persistent, the pain is aggravated at night, the pain is radioactive, often with headache, such affected teeth need to do root canal treatment. If the first molar presents with biting pain, fear of chewing or swelling without hot or cold stimulation, the affected tooth may present with pulpal necrosis or periapical inflammation, and normally should also receive root canal treatment. There are also special kinds of pain, such as sensitivity caused by heavy abrasion, tooth splitting, etc. Therefore, the type of disease should be determined before deciding how to treat it properly.