Redness under a denture: what is denture stomatitis, and how does it clear?

Denture stomatitis is redness and swelling of the tissue in the mouth that lies under the denture. It is seen mostly on the palate covered by an upper denture. A review reports that its frequency varies from study to study between 17 and 75 per cent of denture wearers and that it is a little more common in older women; it is the commonest inflammatory picture inside the mouth among denture wearers.

There is not a single cause, but at the centre there is a layer of microbes. The surface of the denture that faces the tissue, with the pores and roughness of the acrylic, creates a sheltered environment for a sticky layer in which the Candida fungus and bacteria live together. A review written jointly by specialists in prosthodontics, oral medicine and microbiology states that this layer grows mainly through poor mouth and denture hygiene and through wearing the denture all the time, especially at night. The friction a poorly fitting denture creates in the tissue, a dry mouth and smoking are among the factors that make the picture more likely too.

Its telling sign is simple: the border of the redness matches the border of the denture. A sore with a clear edge that hurts at a single spot is more likely to be the denture rubbing, and that is a separate problem. Denture stomatitis usually causes no pain; some people have burning, cracking at the corners of the mouth or a change in taste. Many people only notice it when they take the denture out and look in a mirror.

Clinicians still describe its appearance using the three types Newton defined in 1962. In the first type the redness is confined and pinpoint; according to reviews, this type is linked more with pressure and friction. In the second type the whole area the denture covers is red all over. In the third type the palate takes on a rough, granular appearance with small bumps; this is called inflammatory papillary hyperplasia. The same review also notes that this classification is useful for describing the appearance but does not fully reflect the severity or extent of the disease. In other words, 'type 1' does not mean 'mild'.

The commonest mistake in treatment is looking for the problem only in the mouth. In a meta-analysis combining randomised studies, no significant difference was found between antifungal medicine and denture disinfection in either clinical improvement or fungal counts. In the same analysis, antifungal medicine reduced fungal counts significantly compared with a placebo; but for improvement in the visible redness, the difference did not reach the threshold of statistical significance. Put another way, if the denture is not cleaned, medicine applied to the mouth is only half the job.

A broader network meta-analysis also writes that antifungal medicines, microwave disinfection and antifungal medicines taken by mouth work, but that confidence in these findings is low because of the small number of studies and the risk of bias. The specialist review, for its part, states that antifungal medicines give limited benefit beyond short-term use, because resistance develops with long-term use. The key to a lasting result, in the review's words, is patients changing their own habits: cleaning and disinfecting the denture every day, taking the denture out every night, regular check-ups and replacing the denture when needed.

When medicine is needed, there is a safety detail to know. Azole antifungals such as miconazole increase the effect of the blood thinner warfarin; the review writes that in this case the patient's doctor should be consulted so the dose can be adjusted. If you take warfarin, tell your doctor first, even if it is only a mouth gel from the pharmacy. According to the review, the usual length of antifungal treatment is up to 14 days.

Denture stomatitis may not be a matter confined to the mouth. The same specialist review states that this picture is linked with aspiration pneumonia, and that in frail, older people living in care homes, treating it lowers the risk of aspiration pneumonia and of death from it. If a relative you care for sleeps in their denture, the habit of taking it out at night is more than mouth care for them.

The distinction below does not replace an examination; it helps you decide how long you can wait.

The sequence below is made up of the steps recommended in reviews and care guides. Ask your clinician which solution suits your denture.

1. 1

   Take your denture out every night

   The NHS advises not sleeping in your dentures unless your dentist has specifically told you to. Overnight, keep the denture in water, in a plastic bag with some damp cotton wool in it, or in a denture cleaning solution.

2. 2

   Brush the denture morning and evening

   Brush it with mild soap or washing-up liquid; according to the NHS, toothpaste can damage a denture. Rinse it with cold water after meals. So that it does not break if you drop it, work over a sink filled with water or over a towel.

3. 3

   Disinfect the denture

   In the protocol given as an example in one review, the denture is soaked in 150 millilitres of 0.25 to 0.5 per cent sodium hypochlorite for 10 to 20 minutes before bed, then kept in clean water overnight. The review also notes that frequent soaking in hypochlorite can discolour the denture; decide the strength and frequency with your clinician.

4. 4

   Brush your palate too

   In the same protocol, the palate is brushed three times a day for two minutes each time with a soft toothbrush and water. The NHS also recommends brushing your gums, tongue and any remaining teeth morning and evening.

5. 5

   If medicine has been prescribed, use it for the full course and alongside the denture care

   Antifungal medicine is short-term support. Do not stop cleaning the denture while you use it; if you take a blood thinner, tell your doctor before starting an azole medicine.

6. 6

   Have the fit of the denture checked

   A denture that moves, rubs or has worn out irritates the tissue all the time. Reviews count correcting or replacing a poorly fitting denture as a core part of treatment.

The options are used not instead of one another but usually together. The foundation is always denture hygiene and taking the denture out at night.

If denture stomatitis keeps coming back, one of the following is usually still going on.

The time varies with the type of picture, the state of the denture and how far habits change. The sequence below is a general framework.

1. The first night

   Going to bed with the denture taken out and cleaned makes it the first night the tissue is free of the denture all night. Keep the denture in water or a cleaning solution, and put it in in the morning after brushing and rinsing it.

2. For the length of the medicine

   If antifungal medicine has been prescribed, according to the review the usual length is up to 14 days. During this time, cleaning the denture and taking it out at night carry on just the same; do not extend the medicine yourself.

3. Check-up

   The clinician looks at whether the redness has gone down and at the fit of the denture. If it has not gone down, a culture, relining the denture or replacing it is discussed.

4. The following months

   According to the review, denture stomatitis often comes back after antifungal treatment, and the factors feeding the recurrence are poor mouth and denture hygiene, sleeping in the denture and not replacing a worn-out denture. If it comes back, the cause is usually the denture itself or wearing it at night; regular denture check-ups pick this up early.

Treating denture stomatitis usually runs on simple steps, but its scope can widen depending on these factors:

The type of picture

Widespread redness usually goes down with hygiene and disinfection. A granular, bumpy palate may need an additional procedure or a new denture.

The age and fit of the denture

A denture that fits needs only cleaning. Relining a denture that moves, or making the denture again from scratch, is a separate job.

The need for medicine and tests

Medicine inside the mouth is usually enough. If there is no response, a culture, systemic medicine or a biopsy may come up.

Background conditions

A dry mouth, diabetes, a steroid inhaler or a blood thinner changes how the treatment is planned.