It is perfectly possible to get a filling for a mouth ulcer, but only if the patient is able to tolerate the pain, because there is no direct relationship between these two diseases. When repairing a tooth, the operation is mainly done on the tooth, while mouth ulcers are mainly ulcerative diseases of the mucous membrane located on the lips, cheeks and tongue. However, there is one point to note, for example, lip oral ulcers, when filling teeth will certainly involve the application of instruments that pull the corners of the mouth, such as mouth mirrors or other oral manipulation instruments, which may touch the oral ulcers, and then there will be a significant increase in pain. If the patient has a certain fear of the above situation, he can wait until the mouth ulcer is healed before going to fill the tooth.