Stomatitis: Aphthous and Denture Stomatitis — Diagnosis and Management

Dental Health · Oral and Dental Conditions

Stomatitis: Aphthous and Denture Stomatitis — Diagnosis and Management

Stomatitis means inflammation of the oral mucosa. It is a descriptive term, not one single disease: mouth soreness or ulceration can result from trauma, recurrent aphthous stomatitis, infection, dentures, medicines, nutritional deficiency or systemic illness. Correctly identifying the pattern matters because an aphthous ulcer, oral herpes, candidiasis and denture-related inflammation do not have the same cause or treatment.

This study guide focuses on recurrent aphthous stomatitis and denture stomatitis, while outlining a safe approach to oral ulceration and common differentials. It expands the supplied teaching slide and uses current clinical guidance. It is intended for health-science learning; diagnosis and treatment of an individual patient require assessment by a trained dental or medical professional using local Ugandan protocols.

1. Meaning of stomatitis and key terms

The word stomatitis refers broadly to inflammation of the oral mucosa. It may cause redness, soreness, erosions, blisters, white patches or ulcers. A clinician describes the lesion and its distribution before assigning a cause.

• Oral mucosa: the moist lining of the mouth, including the lips, cheeks, floor of mouth, tongue, palate and gingiva.
• Ulcer: a break in the surface lining that exposes underlying tissue. It may be painful and can follow trauma or systemic disease.
• Erosion: a shallow loss of the surface epithelium; it is usually more superficial than an ulcer.
• Vesicle: a small fluid-filled blister. Vesicles may rupture and leave erosions or ulcers.
• Aphtha: a recurrent, usually round or oval painful ulcer on the oral lining mucosa. Recurrent aphthous stomatitis (RAS) is not caused by herpes simplex and is not contagious.
• Denture stomatitis: erythema and inflammation of mucosa in contact with a removable denture, most often the palate under an upper denture. Candida may contribute, but the condition is multifactorial.
• Angular cheilitis: inflammation, cracking or soreness at one or both corners of the mouth; it may coexist with denture-related or Candida-associated disease.
• Induration: abnormal firmness within or beneath a lesion. Induration, fixation or a raised irregular edge increases concern and warrants prompt assessment.

2. Types and patterns

Recurrent aphthous stomatitis

RAS causes episodes of painful, recurring ulcers on movable, non-keratinised lining mucosa such as the inner lips and cheeks, ventral tongue or floor of mouth. A burning or tingling sensation may occur before a lesion appears. The cause is often unknown; immune-mediated inflammation is thought to be involved. Trauma, stress, hormonal change, medicines or a low level of iron, folate or vitamin B12 may be associated in some patients, but no single trigger explains every case.

Minor aphthae typically affect movable lining mucosa. A lesion on the hard palate or attached gingiva, a blistering eruption, an ulcer that does not heal, or ulcers accompanied by skin, genital, eye, joint or gastrointestinal symptoms should prompt consideration of another diagnosis or an underlying condition.

Denture stomatitis

Denture stomatitis appears as erythema or inflammation of mucosa that lies under a removable denture, particularly an upper acrylic plate. It can be asymptomatic or cause soreness, burning, altered taste or discomfort. A clinician may describe localised pinpoint redness, more diffuse erythema or a granular/papillary surface. The appearance alone does not prove that Candida is the only cause.

Contributing factors include continuous or overnight denture wear, inadequate denture and palate cleaning, an ill-fitting or worn denture, denture surface biofilm, dry mouth, smoking, diabetes, recent antibiotic exposure, immune suppression and some inhaled or topical medicines. The denture can act as a reservoir for biofilm, so treating the mucosa without improving denture care may lead to recurrence.

Other common causes of stomatitis or oral ulcers

Pattern or cause	Clues that help distinguish it	Next step
Traumatic ulcer	Single lesion near a sharp tooth, cheek bite, burn, rough filling or denture edge; often corresponds to a local irritant.	Remove or correct the cause within scope and review healing. A persistent lesion still needs assessment.
Herpes simplex	May begin with grouped blisters; recurrent cold sores commonly affect the lip border. Primary oral infection can cause widespread painful gingivitis and ulcers.	Assess timing, distribution, systemic symptoms and risk factors; avoid assuming that every cluster of ulcers is aphthous disease.
Oral candidiasis	White plaques that may wipe away to leave a red surface, or red/burning mucosa; risk rises with dentures, dry mouth, antibiotics, inhaled steroids or immune suppression.	Confirm the clinical pattern and contributors; treat the cause and use antifungal therapy only when indicated by a qualified clinician.
Hand, foot and mouth disease or other viral illness	Oral vesicles/ulcers with fever or a rash on hands, feet or elsewhere, often in children.	Assess hydration and general condition; follow local infection-control and referral guidance.
Immune or inflammatory disease	Recurrent extensive ulcers, genital ulceration, eye inflammation, skin lesions, gastrointestinal symptoms or joint symptoms.	Consider Behçet disease, inflammatory bowel disease, coeliac disease or another systemic cause; arrange medical or specialist review.
Medicine-related or nutritional factors	New medication, dry mouth, repeated ulceration, anaemia symptoms or restricted diet.	Review medicines and history; consider targeted investigations. Do not stop a prescribed medicine without its prescriber.
Potential oral malignancy	Persistent solitary ulcer, firm or raised edge, induration, unexplained red/white patch, neck node, progressive swallowing difficulty or weight loss.	Prompt dental/oral medicine assessment and referral using the local suspected-cancer pathway.

3. Causes and risk factors

Why aphthous ulcers recur

For many patients, no clear underlying cause is found. RAS is generally considered a recurrent inflammatory disorder rather than an infection. Local trauma can precipitate a lesion in a susceptible person. Some patients report associations with stress, tiredness, hormonal changes, certain foods or toothpaste ingredients. These experiences are individual and should be explored rather than assumed.

Recurrent or unusually severe ulcers can be associated with deficiencies such as iron, folate or vitamin B12, coeliac disease, inflammatory bowel disease, Behçet disease, cyclic neutropenia, immune suppression or certain medicines. A deficiency should be confirmed and treated appropriately; routine supplements without assessment can miss the actual cause or create avoidable harm.

Why denture stomatitis develops

Denture stomatitis is usually a combination of mucosal irritation and denture biofilm. Continuous denture wear reduces the time that covered tissue is exposed to saliva and air. Incomplete cleaning, poor fit, an ageing or rough surface, dry mouth and general health factors can further disrupt the mucosal barrier. Candida may be present as a commensal organism in the mouth and can overgrow under favourable conditions; detecting or suspecting Candida should be interpreted alongside the examination.

Risk review checklist

• How often lesions occur, how long they last and whether they leave scars.
• Recent trauma, sharp teeth, appliances or ill-fitting dentures.
• Smoking, alcohol use, sleep, stress and reported food or toothpaste triggers.
• Dietary restrictions, weight change, possible anaemia or previous nutrient deficiency.
• New or changed medicines, antibiotics, inhaled corticosteroids and medicines that cause dry mouth.
• Diabetes, immune suppression, HIV status where clinically relevant and other chronic conditions.
• Genital ulcers, eye symptoms, skin lesions, fever, abdominal symptoms or joint pain.
• Denture age, fit, cleaning method, overnight wear and availability of denture-care products.

4. Clinical features

Aphthous stomatitis

Patients often describe pain that worsens with acidic, salty, spicy or rough food, brushing or speaking. Minor lesions are usually round or oval, with a shallow pale base and a surrounding erythematous halo. They recur after healing, commonly without a preceding blister. Major ulcers are deeper, larger and longer-lasting; they may scar. The person is usually otherwise well in uncomplicated RAS.

Denture stomatitis

Look for a red area that maps to the denture-bearing surface, often beneath a maxillary denture. The mucosa may be diffusely erythematous or show papillary changes. Ask whether the denture is worn during sleep and whether it is painful or loose. A denture wearer can also have angular cheilitis, oral candidiasis elsewhere, trauma from a sharp edge or an unrelated mucosal lesion. A unilateral, irregular, indurated or ulcerated area should not be dismissed as ordinary denture stomatitis.

5. History, examination and investigations

Focused history

1. Characterise the lesion: first episode or recurrent; onset; number; site; size; pain; any tingling, blistering or bleeding; healing time; scarring; and whether the same sites recur.
2. Look for triggers: cheek biting, sharp teeth, dental work, a new denture, food or toothpaste triggers, smoking changes, stress and sleep disruption.
3. Ask about systemic features: fever, malaise, weight loss, gastrointestinal symptoms, genital ulcers, eye inflammation, skin lesions and joint symptoms.
4. Review health and medicines: relevant medical conditions, immune status, diabetes, allergies, recent antibiotics, prescribed and over-the-counter medicines, inhalers and dry mouth.
5. Assess hydration and function: ability to eat, drink, swallow and speak; urine output where relevant; and any weight loss caused by painful lesions.
6. For denture wearers: type and age of denture, hours worn, overnight use, fit, cleaning and storage routines, cleanser used, and whether it is removed for cleaning.
7. Ask the patient’s goals: what concerns them most, what has helped, what they have tried and any access barriers.

Oral and extra-oral examination

1. Assess general appearance, hydration, fever, facial swelling and ability to open the mouth, swallow and breathe.
2. Examine the lips and skin around the mouth for crusting, vesicles, fissures or trauma.
3. Remove dentures if tolerated. Inspect the denture-bearing mucosa, palate, tongue, floor of mouth, cheeks, gingiva and oropharynx in a consistent sequence.
4. Record lesion number, site, size, shape, base, edge, surrounding redness, tenderness, induration, wipeability of any white coating and distribution in relation to the denture.
5. Look for sharp teeth, broken restorations, cheek biting, denture pressure areas, poor denture hygiene and signs of candidiasis or another mucosal condition.
6. Palpate a suspicious lesion and relevant cervical nodes when trained and appropriate; document a lump, fixation, induration or unexplained node.
7. Compare with prior episodes or photographs only with the patient’s agreement, and document consent, findings and a clear review plan.

Investigations

A typical short-lived minor aphthous ulcer in an otherwise well patient is usually diagnosed clinically. Recurrent, severe, extensive or atypical disease may warrant targeted blood tests such as a full blood count, ferritin/iron studies, vitamin B12 or folate, and other tests guided by the history and local protocols. Suspected coeliac disease or systemic inflammatory disease requires appropriate medical evaluation. A swab or fungal assessment may be useful when infection is suspected or the presentation is not responding as expected. Biopsy or specialist oral medicine assessment may be needed for a persistent, indurated, unusual or suspicious lesion. Tests should answer a clinical question; they are not a substitute for referral when cancer is suspected.

6. Management principles

Treatment depends on the cause, severity, patient age and health, and the clinician’s scope of practice. The priorities are to relieve pain, maintain hydration and nutrition, remove an irritant, identify a treatable underlying factor and arrange review. Explain uncertainty honestly when no cause is found.

Supportive care for uncomplicated aphthous ulcers

• Explain that minor aphthae are not contagious and often heal spontaneously within one to two weeks.
• Use a soft toothbrush and gentle oral hygiene. Avoid rough, very hot, acidic, salty or spicy foods while the lesion is painful; choose cool fluids and softer foods.
• A warm saline rinse may soothe the mouth; rinse and spit rather than swallowing it. Commercial mouth rinses or topical pain-relief preparations may help when suitable and used according to their directions.
• Discuss a suspected toothpaste or food trigger only if the timing supports it. Changing to an alternative toothpaste can be considered if sodium lauryl sulphate appears to irritate the patient, but a trigger is not universal.
• For recurrent or painful disease, a dental or medical professional may consider a topical corticosteroid early in an episode or another topical treatment. First assess whether infection or another diagnosis is plausible; steroid treatment can worsen some infections.
• Consider investigations and treatment for a confirmed iron, folate or vitamin B12 deficiency, or referral for a systemic cause. Do not prescribe supplements or systemic immunosuppressive medicines solely from the appearance of an ulcer.
• Severe, persistent or disabling RAS may require oral medicine or specialist input. Systemic medicines have significant risks and require an individual indication and monitoring.

Management of denture stomatitis

1. Clean the tissues: advise gentle daily cleaning of the palate and oral mucosa as appropriate, alongside routine tooth and gum care.
2. Clean the denture every day: brush all surfaces using a denture brush and a suitable cleanser, then rinse. Follow product and dental advice for the specific denture material.
3. Remove the denture during sleep and when practical: giving the mucosa regular rest can help reduce continuous irritation and moisture retention.
4. Check fit and condition: a dentist should assess pressure areas, roughness, instability and the need for adjustment, repair or replacement. Do not attempt to grind or reshape a denture at home.
5. Address contributing factors: review dry mouth, smoking, diabetes, medicines and inhaler technique where relevant; coordinate changes with the appropriate prescriber.
6. Use medicines only when indicated: if Candida is clinically suspected or confirmed, a qualified clinician may add a topical antifungal to local denture and mucosal care. Systemic antifungals are not routinely needed for uncomplicated denture stomatitis and can cause adverse effects or interactions.
7. Make the cleanser material-safe: some soaking agents, including hypochlorite, can damage dentures with metal components or certain materials. Use only a cleanser known to be suitable for that denture and follow professional instructions.
8. Review response: arrange follow-up to confirm the mucosa improves and the denture is comfortable. Persistent, asymmetric or ulcerated changes need reassessment rather than repeated empirical antifungal treatment.

7. Referral and urgent warning signs

Prompt dental or oral medicine review

• An unexplained mouth ulcer lasting longer than three weeks, or an ulcer that is enlarging or not following the patient’s usual healing pattern.
• A firm, fixed, irregular or raised lesion; an unexplained red or white patch; a lump in the mouth or neck; or unexplained numbness.
• Recurrent major ulcers, many ulcers at once, frequent recurrence that disrupts eating, or scarring.
• Oral ulcers together with genital ulcers, painful red eyes, skin lesions, joint swelling, persistent gastrointestinal symptoms or unexplained fever.
• Denture-related erythema that persists despite suitable denture hygiene, night removal and professional review of fit.

Guidelines in some countries use an unexplained oral ulcer lasting more than three weeks as a trigger to consider a suspected-cancer pathway referral. Follow the current local Ugandan referral route; do not delay assessment of a lesion that is clinically suspicious while waiting for the three-week mark.

Emergency escalation

Difficulty breathing or swallowing, rapidly spreading facial or neck swelling, severe dehydration, inability to maintain fluids, high fever with deterioration, trismus or a seriously unwell immunocompromised patient needs urgent medical or hospital assessment under local emergency pathways.

8. Prevention and patient education

• Brush gently with a soft-bristled toothbrush and maintain regular oral hygiene, even when a small ulcer makes brushing uncomfortable.
• Keep removable dentures clean, remove them overnight when possible, clean the palate and arrange dental review if they rub, loosen or cause recurring soreness.
• Identify and correct sharp teeth, rough restorations or denture pressure points through professional care.
• Maintain a varied diet and seek assessment for repeated ulcers rather than taking high-dose supplements without a confirmed indication.
• Review medicines with a clinician if ulcers start after a medication change; never stop an important prescribed medicine independently.
• Support tobacco cessation and manage dry mouth or diabetes with the appropriate care team.
• Give the patient specific return advice: seek review for worsening pain, fever, poor fluid intake, new systemic symptoms or a lesion that fails to heal.

9. Worked examples

Example A: recurrent minor aphthae

A 21-year-old student reports two or three small painful ulcers on the inside of the lower lip every few months. Each heals within about ten days and leaves no scar. There is no fever, rash, genital ulceration or eye symptom. Examination shows shallow round ulcers with pale centres and red margins on movable lining mucosa. A focused history checks trauma, diet, medicines and systemic symptoms. The pattern is consistent with minor RAS, but recurrence frequency and impact guide whether further review or targeted tests are appropriate. Advice covers gentle oral care, symptom relief, possible triggers and review if an ulcer becomes persistent or atypical.

Example B: erythema under an upper denture

A 68-year-old denture wearer has painless redness over the palate. They wear the denture overnight and clean it irregularly. The clinician removes the denture, examines the whole mouth, checks the fit and looks for ulcers, white plaques or lesions outside the denture-bearing area. Advice includes daily denture and palate cleaning, removing the denture during sleep and dental review of the fit. Antifungal medicine is considered only if the examination supports Candida-associated disease. If the red area fails to improve or develops a persistent ulcer or firm area, the diagnosis must be reconsidered and the patient referred.

10. Common mistakes to avoid

• Using “stomatitis” as a complete diagnosis without describing the site, appearance and likely cause.
• Calling aphthous ulcers “herpes” or implying that recurrent aphthae are contagious.
• Assuming all oral ulcers are benign or treating a persistent lesion repeatedly without reassessment.
• Prescribing topical or systemic steroids before considering herpes, candidiasis or another infection.
• Giving antifungal therapy alone for denture stomatitis while ignoring denture biofilm, overnight wear and poor fit.
• Recommending a denture soak without checking that the product is safe for the denture material.
• Attributing repeated ulcers to a vitamin deficiency without history, examination or appropriate testing.
• Stopping a prescribed medicine or recommending antibiotics without an appropriate indication.
• Failing to assess hydration, systemic symptoms, cervical nodes or the patient’s ability to eat and drink.

11. Key takeaways

• Stomatitis describes inflammation of the oral mucosa; it is not a single diagnosis.
• Recurrent aphthous stomatitis causes non-contagious ulcers on oral lining mucosa. Minor ulcers usually heal within one to two weeks; major or atypical lesions need assessment.
• Denture stomatitis is redness beneath a removable denture and is often multifactorial. Denture and palate hygiene, night removal and assessment of denture fit are central.
• History and examination should look for trauma, infection, medicines, nutritional factors and systemic symptoms.
• Targeted tests or specialist review are appropriate for severe, recurrent, atypical or persistent lesions.
• An unexplained ulcer persisting beyond three weeks, or a suspicious lesion at any duration, warrants prompt referral according to local pathways.

12. Self-assessment questions

1. What does the term stomatitis describe, and why is it not a complete diagnosis?
2. Which oral sites are commonly affected by recurrent aphthous ulcers?
3. How do minor aphthae differ from major aphthae?
4. Why are herpetiform aphthae not the same as herpes simplex infection?
5. Name four factors that may contribute to denture stomatitis.
6. What questions help characterise a recurrent oral ulcer?
7. When may targeted blood tests be appropriate in recurrent aphthous stomatitis?
8. Give four local measures that can help manage denture stomatitis.
9. Why should the material of a denture be checked before recommending a soaking cleanser?
10. List four warning signs that should prompt referral.

Suggested answers

1. It describes inflammation of oral mucosa from several possible causes; examination and history are needed to identify the condition.
2. Movable lining mucosa such as the inner lips and cheeks, ventral tongue and floor of the mouth.
3. Minor ulcers are usually small and heal without scarring within about 7–14 days; major ulcers are larger, deeper, more prolonged and may scar.
4. Herpetiform describes the appearance of many tiny grouped aphthous ulcers; RAS is not caused by herpes simplex and is not contagious.
5. Examples include continuous or night-time wear, inadequate cleaning, poor fit, denture biofilm, dry mouth, smoking, diabetes, antibiotics and immune suppression.
6. Ask about onset, site, number, pain, size, recurrence, healing time, scarring, blisters, trauma, triggers and systemic symptoms.
7. When ulcers are frequent, severe, extensive, atypical or accompanied by history suggesting anaemia, nutritional deficiency or systemic illness; testing should be guided by a clinician.
8. Clean the palate, clean the denture daily with a material-safe product, remove it during sleep or when practical, and have its fit and condition reviewed.
9. Some chemicals can damage metal or other denture materials; a cleanser must be safe for that specific appliance.
10. Examples include an unexplained ulcer lasting more than three weeks, induration or a firm irregular edge, a mouth or neck lump, a red/white patch, systemic symptoms, eye/genital lesions, poor hydration or difficulty swallowing/breathing.

Further learning and references

• Recurrent Aphthous Stomatitis — supplied teaching slides. Use as a study aid; verify clinical decisions against current guidance.
• University College London Hospitals: Recurrent aphthous stomatitis ulcers.
• Scottish Dental Clinical Effectiveness Programme: Denture stomatitis.
• SDCEP: Local measures for denture stomatitis.
• NHS: Mouth ulcers — self-care and when to seek assessment.
• NICE guideline NG12: Oral cancer recognition and referral recommendations. Apply the relevant local referral pathway.
• American Academy of Oral Medicine: Canker sores (recurrent aphthous stomatitis).
• DermNet: Aphthous ulcer — clinical features and differential diagnosis.

Continue learning

• Dental health definitions, key terms and tooth anatomy
• Dental instruments and equipment
• Dental history taking and oral examination
• Dental anaesthesia: local and general methods
• Tooth extraction: indications, techniques and complications
• Oral ulcers: causes, symptoms and management
• Clinical Medicine Year 2 curriculum

Educational note: This article supports health-science learning and does not replace individual examination, supervised training, local Ugandan protocols or referral advice. Treatment decisions should be made with an appropriately trained dental or medical professional.