What causes a mouth sore? Mouth sores are found at the corners of the mouth on the lips. It can be caused by several common things such as: Cold sore/fever blister Vitamin or iron deficiency Poorly fitting dentures Fungal infection (thrush) Cold sores: If you have had cold sores/fever blisters in the past, you probably know when you are going to get another one. These sores usually occur in the same place each time they pop up. It takes 7 to 14 days to go away. They can be caused by a type of herpes virus or by tooth loss. The jaws are collapsed and the folds of skin at the corners of the mouth bunch up, resulting in mouth sores. Often these sores will appear when you have been sick or run down, or you may get them after you have been out in the sun or have sunburn. Ointments and creams are available without a prescription. They lessen the severity of the sore and the number of days it takes to go away. If you have many outbreaks, see a dentist or doctor for a prescription for a stronger cream. Use at the first sign of an outbreak. Make sure you use a cotton swab or rubber/latex gloves when putting the cream on the sore. Do not touch the sore with your hands. The virus can be spread to other people and to other parts of your body such as your eyes. Vitamin or iron deficiency: Mouth sores also result from a low level of vitamin B or iron in your body dental supplies. Many older adults do not pay attention to how many vitamins, minerals and other nutrients are in their diets. It is very important to watch what you eat. After a certain age many people find it is very easy to gain weight. In order to offset this, we eat less. The problem is, we still require the same amount of vitamins, minerals and nutrients, but not as many calories as when we were younger. This makes food choice very important dental curing light. We need to eat foods that have more nutrients and less “empty” calories. Your doctor or dentist may suggest you take a daily vitamin supplement to help you keep a good level of vitamins in your body. Poorly fitted dentures: Dentures that have worn down over the years and do not fit properly may cause mouth sores. Worn dentures cause your mouth to close more than it did when the dentures were new. This causes the skin at the corners of your mouth to fold over or overlap dental lab equipment. When this happens, the area in the fold of skin stays very warm and moist and can be a perfect place for a fungal infection or thrush to develop. Antifungal creams and ointments treat thrust, but it will come back again if the dentures are not fixed or replaced and the overlapping skin remains.