Short answer: Mouth sores are most often canker sores, cold sores or traumatic sores caused by friction from appliances such as braces, clear aligners and dentures. Canker sores can be triggered by stress, minor injuries, vitamin deficiencies and hormonal changes, and usually heal within one to two weeks. Rinsing with salt water, avoiding irritating foods and using a soft brush can bring relief. Sores that last longer than two weeks, grow or recur frequently should be seen by a doctor.
A small sore that causes a sharp pain while eating, talking or brushing your teeth can make daily life unexpectedly difficult. Not every mouth sore, which is very common, has the same cause: some are canker sores, some are cold sores, and some are sores caused by friction from appliances such as braces, clear aligners or dentures. Although most heal on their own within one to two weeks, some sores need to be evaluated. In this article, we explain the types of mouth sores, the possible causes of canker sores, appliance-related sores, ways to find relief at home and when you should see a doctor.
What are the types of mouth sores?
Mouth sores fall into a few groups, most commonly canker sores, cold sores and sores caused by mechanical irritation. Because their appearance, location and course differ, knowing which type of sore you have helps you choose the right care.
- Canker sores (aphthous ulcers): Painful, round or oval sores with a white-yellow center and a red ring around them, found on the movable soft tissues inside the mouth (the inner cheeks and lips, under the tongue, the sides of the tongue). They are not contagious.
- Cold sores: Sores caused by the herpes virus, which usually start as clusters of small fluid-filled blisters on the edge of or around the lips. The blisters burst and crust over. They are contagious.
- Traumatic sores: These form due to cheek biting, hard brushing, hot foods, a broken tooth edge or friction from oral appliances.
- Fungal infection: May appear as white patches that can be wiped off, with redness underneath.
- Childhood viral infections: Some viral illnesses can cause many small sores in the mouth, fever and rashes on the hands and feet.
Apart from these, some sores may be the oral manifestation of general health conditions or more serious tissue changes. For this reason, sores that do not heal for a long time should always be evaluated.
What causes canker sores?
The exact cause of canker sores is not fully known; however, factors such as stress, minor injuries, certain vitamin and mineral deficiencies, hormonal changes and some foods are thought to trigger them. Canker sores are generally not contagious and appear occasionally in most people.
The main factors that can trigger canker sores are:
- Stress, lack of sleep and fatigue
- Minor injuries such as cheek biting, a hard toothbrush or dental procedures
- Iron, vitamin B12 or folic acid deficiency
- Hormonal changes related to the menstrual cycle
- In some people, acidic or spicy foods, chocolate, nuts
- The foaming agent found in some toothpastes (sodium lauryl sulfate)
- A family history of canker sores
Canker sores are mostly smaller than one centimeter and heal without scarring within one to two weeks. Larger, deeper and longer-lasting canker sores may leave a scar as they heal. Very frequent, large or numerous canker sores may be associated with general health conditions such as celiac disease, inflammatory bowel diseases or Behçet's disease. Especially if mouth sores are accompanied by eye, skin, joint or genital complaints, you should see the relevant doctor.
How do aligner and denture sores form?
Because orthodontic appliances and dentures are in constant contact with the soft tissues of the mouth, they can cause friction sores, especially during the first period of use. These sores usually form where the appliance has a sharp edge or an area that puts pressure on the tissue.
Clear aligners and braces
Although clear aligners are custom-made, in some patients the edge of the aligner can rub against the gums or the side of the tongue and cause small sores. This usually happens during the first days after switching to a new aligner. If the edge of the aligner is bothering you, rather than trying to cut or file it at home, you should see your orthodontist; they can make the necessary adjustment in a controlled way. We covered this and similar situations you may encounter with aligners in detail in our article on clear aligner problems. With fixed braces, friction from brackets and wire ends against the inner cheeks and lips can cause sores; in this case, orthodontic wax provides temporary protection and poking wire ends are adjusted by the orthodontist.
Dentures
Newly fitted removable dentures, or those whose fit has deteriorated over time, can cause pressure sores on the gums. People with denture sores are advised not to file the denture themselves, but to see their dentist to have it adjusted. Removing the denture at night and cleaning it every day helps both the healing of sores and the prevention of fungal infections. Because ill-fitting dentures that press on the same spot for a long time can cause permanent changes in the oral tissues, regular check-ups are important.
How do mouth sores heal? Ways to find relief at home
Most mouth sores heal on their own within one to two weeks; what you can do at home is aimed at reducing pain and supporting healing. These measures do not remove the cause of the sore, but they can make the process more comfortable.
- Rinsing with warm salt water: Gentle rinsing a few times a day can help keep the sore area clean.
- Avoiding irritating foods: Spicy, acidic, very salty, very hot and hard, crunchy foods can increase pain.
- Using a soft brush: Gently clean around the sore and do not neglect your oral care.
- Toothpaste without foaming agents: For some people who get frequent canker sores, toothpastes without sodium lauryl sulfate may help.
- Drinking plenty of fluids: Keeping the mouth moist contributes to relief.
- Protective gels sold in pharmacies: They can ease pain by covering the sore; a doctor or pharmacist should be consulted before use.
- Stress management and regular sleep: Can help reduce triggers in recurring canker sores.
With cold sores, on the other hand, not touching the sores, paying attention to hand hygiene and avoiding close contact while the blisters are active are important to prevent spreading. For frequently recurring or widespread cold sores, you can see a doctor for treatment.
When should you see a doctor?
Mouth sores that last longer than two weeks, keep growing, recur frequently or are accompanied by general symptoms such as fever should always be seen by a doctor. Early evaluation helps both to find the underlying cause and to recognize serious conditions in time.
An examination is recommended in the following situations:
- A sore that does not heal within two weeks
- A sore larger than one centimeter, deep or with hardened edges
- A sore or red-white patch that does not go away even though it is not painful
- Canker sores that recur several times a year
- High fever, weakness or swelling in the neck together with the sore
- Difficulty swallowing or speaking
- Accompanying complaints in the eyes, skin, joints or genital area
- An oral appliance repeatedly causing a sore in the same spot
Especially in people who smoke and drink alcohol, evaluating sores that last longer than two weeks with no explained cause is very important. For your other questions about oral and dental health, you can take a look at our frequently asked questions page.
Examination for mouth sores in Ankara
If you have a mouth sore that does not heal or keeps recurring, or an area that your clear aligner or denture constantly irritates, an examination is recommended to determine the cause and find the right solution. At our polyclinic next to Panora Mall in Çankaya, we examine your oral tissues, make the necessary adjustments for appliance-related problems and refer you to the relevant specialty when needed; you can use our contact page to make an appointment.
Frequently asked questions
Are canker sores contagious?
No, canker sores are not contagious. Cold sores, which start with fluid-filled blisters around the lips, are caused by a virus and are contagious. The location and appearance of the sore give important clues for telling the two apart.
How long does it take for a canker sore to heal?
Small canker sores usually heal without scarring within one to two weeks. Large and deep canker sores can take longer and may leave a scar as they heal. Sores lasting longer than two weeks should be seen by a doctor.
What should I do if my clear aligner is causing a sore in my mouth?
If the edge of the aligner is rubbing against your gums or tongue, do not try to cut or file it at home. See your orthodontist so that the necessary adjustment can be made in a controlled way. In the meantime, rinsing with salt water can help the sore heal.
Can frequent canker sores be a sign of illness?
Occasional canker sores are mostly harmless. However, very frequent, large or numerous canker sores may be associated with vitamin deficiencies or certain general health conditions. In this case, you should see a doctor to investigate the cause.
