There is no clear clinical report to show how long it will take for the oral mucosa to recover after quitting betel nut, but it needs to be judged according to the length of time the patient chews betel nut and daily eating habits. First, betel nut is hard and easy to wear teeth after chewing, making teeth loose, damaging periodontal health, damaging oral mucosa, or making teeth black. Secondly, the substances contained in betel nut can react with saliva to produce nitrite substances, often chewing betel nut will increase the chances of cancer, especially oral cancer. Third, betel nut residue is hard, can stimulate the stomach wall, gastritis, and even gastric perforation, affecting the function of the digestive system. Fourth, long-term eating betel nut is easy to addiction, can cause central nervous disorder, hallucinations. Therefore, it is recommended that the majority of friends, especially those prone to oral ulcers and mucosal diseases, try to chew betel nut or not, to create a good oral environment.