The reason why the toothache in the afternoon does not hurt in the morning may be caused by dentin hypersensitivity, and periodontitis, pulpitis, dental caries and other factors. 1. Periodontitis: also known as destructive periodontal disease, mainly due to plaque invasion of periodontal tissues and caused not only by red and swollen gums, but also because of the food debris left behind for a long time, so some patients will be manifested in the afternoon toothache in the morning. 2. Pulpitis: most of the development of dental caries, and bacterial infection, chemical and physical stimuli, mainly manifested as pain, especially when there will be hot and cold temperature stimulation or sweet and sour chemical stimulation of the pain response, may be exacerbated by food chewing, resulting in acute inflammatory infiltration, which may be manifested as a toothache in the afternoon and morning pain. 3. Dental caries: patients will have obvious pain to cold, hot, sour and sweet stimuli, which is caused by bacterial infection factors and the destruction of the hard tissue of the teeth, especially in the case of poor dietary habits induced, for example, when eating hard objects, there may be afternoon toothache in the morning. Of course, in addition to the above factors there may be other reasons, you can go to the hospital stomatology department, with the doctor to improve the relevant examination, and then give the corresponding treatment and therapy.