Frequent mouth ulcers are generally caused by the following reasons: 1, the presence of stimulating factors in the mouth, such as the patient’s mouth has a thin-walled weak tip often stimulate the oral mucosa, it is easy to damage, into recurrent mouth ulcers. The patient must promptly grind out the thin-walled weak tip to eliminate stimulation, otherwise, it is easy to develop cancer. 2, it is likely that the late restoration is not suitable, if the patient itself has dentures or all-ceramic restorations in the mouth, it is likely to stimulate the mucosa and needs to be removed or replaced in a timely manner. 3, mental factors, if the patient is under a lot of psychological pressure, very tired at work, lack of sleep, it is also likely to lead to a decrease in resistance and The appearance of mouth ulcers.