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Understanding Mouth Ulcers and How Best to Treat Them

Mouth ulcers – those small, painful sores inside your mouth or on your gums – are a common annoyance many of us have experienced. While uncomfortable and sometimes irritating, they’re usually harmless. In most cases, they’ll heal on their own.

But understanding what causes them, how to treat them, and what you can do to avoid them can make a big difference in how quickly you feel better.

At John Miller Dental Practice in Oxfordshire, we believe in giving our patients clear, straightforward advice – so here’s everything you need to know about mouth ulcers.

What Are Mouth Ulcers?

A “mouth ulcer” is the general term for a sore that appears on the inside of your cheeks, lips, tongue, gums or roof of your mouth. The most common type is known as an “aphthous ulcer” (also sometimes called a “canker sore”).

Usually, a typical mouth ulcer looks like a small, round or oval sore with a white or yellowish centre and a red border. It can feel painful especially when you’re eating, drinking or brushing your teeth.

Good news: in most cases, a simple mouth ulcer is not contagious. You can’t catch it from someone else, and conversely, you’re unlikely to pass it on.

What Causes Mouth Ulcers?

There’s no single cause for mouth ulcers, but several triggers and risk factors have been identified. Common ones include:

• Minor injuries or trauma – e.g. accidentally biting the inside of your cheek or lip, injury from sharp food or rough/crunchy foods, poorly fitting or sharp-edged dentures, braces or dental work.
• Oral hygiene products – some people are sensitive to ingredients such as sodium lauryl sulfate (SLS), found in many toothpastes and mouthwashes.
• Diet and eating habits – acidic, spicy or salty foods and drinks can irritate the mouth.
• Nutritional deficiencies – a lack of certain vitamins/minerals (e.g. iron, folate, vitamin B12, zinc) may make some people more prone to ulcers.
• Stress and lifestyle factors – emotional stress, lack of sleep, hormonal changes (for example during periods or pregnancy) can trigger ulcers.
• Underlying health problems – in some cases, recurrent or persistent mouth ulcers might relate to conditions like coeliac disease, inflammatory bowel disease (IBD), or other immune-related issues. Because there are many possible triggers, sometimes an ulcer seems to appear “out of nowhere.”

How to Treat Mouth Ulcers – What Works

The good news is – most mouth ulcers heal on their own within about 1–2 weeks, even without treatment. But if you’d prefer to ease the discomfort and speed healing, here are some helpful approaches often recommended by dentists and pharmacists:

Simple Home Care & Remedies

• Salt-water rinses: Mix a teaspoon of salt in warm water and gently rinse your mouth a few times a day. This can help soothe the ulcer and keep the area clean.
• Gentle oral hygiene: Use a soft-bristled toothbrush, avoid abrasive toothpastes or mouthwashes (especially those with SLS or alcohol), and brush carefully.
• Diet and eating habits: While healing, try to avoid spicy, acidic, salty, very crunchy or very hot foods and drinks. Choose softer, milder foods and drink plenty of water to stay hydrated.
• Lifestyle :Reduce stress if possible, get sufficient sleep, and maintain a balanced, nutrient-rich diet – especially ensuring adequate iron, folate, zinc and B-vitamins.
• 🩹 Over-the-Counter (OTC) Aids If the ulcer is painful or more bothersome, there are non-prescription products that can help:
• Mouthwashes (especially antimicrobial or alcohol-free ones) can help prevent infection and speed up healing.
• Pain-relieving gels, lozenges, sprays, or pastes (containing mild local anaesthetics) that you apply directly on the sore – helpful for reducing discomfort.

When to See a Dentist or Doctor

Although most mouth ulcers are minor and self-limiting, you should seek professional advice if: An ulcer lasts longer than 3 weeks

• It keeps coming back (new ulcers appear before old ones heal)
• It’s unusually large, or become very painful, red, swollen or bleeds
• You have a high temperature/fever or feel generally unwell
• You have multiple ulcers, or ulcers on gums/roof of the mouth, or outside the mouth
• There may be an underlying condition (e.g. immune-suppression, gastrointestinal disease, nutritional deficiency) that needs checking

At John Miller Dental, we’re always happy to examine persistent ulcers, assess whether there might be contributing dental factors (e.g. sharp fillings or denture issues), and advise you on safe treatment or onward referral if needed.

How to Prevent Mouth Ulcers – Reduce the Risk

While you can’t guarantee never to get a mouth ulcer, you can take steps to reduce how often you do, or how severe they are. Some useful prevention tips:

• Maintain good oral hygiene – brush gently twice a day, floss, use a soft brush, and avoid harsh toothpastes or mouthwashes (e.g., those containing SLS or alcohol).
• Eat a balanced diet, rich in vitamins and minerals (especially B-vitamins, iron, zinc) – and stay well-hydrated.
• Avoid known trigger foods or drinks (e.g. very acidic, spicy, salty, crunchy, or hot items) if you notice they tend to precede ulcers.
• Be gentle when eating – avoid accidentally biting cheeks or lips; chew carefully and avoid talking while chewing.
• If you wear braces, dentures, or have dental work, ask your dentist about smoothing or waxing sharp edges.
• Manage stress, get enough sleep, and monitor general health (including nutrition). Chronic stress, lack of sleep or systemic health issues can predispose to ulcers.
• Visit your dentist regularly for check-ups – good preventive dental care helps catch and correct issues (e.g. rough fillings, ill-fitting dentures) that might trigger ulcers.

FAQs on Mouth Ulcers

Here are the most common questions patients ask – with easy-to-understand answers.

When to Contact John Miller Dental Practice

At John Miller Dental Practice we know that recurrent or persistent mouth ulcers can be bothersome – especially when they interfere with eating, speaking or everyday life. We encourage you to give us a call if:

• Your ulcer hasn’t healed within 3 weeks
• You have multiple ulcers, or they keep returning
• The ulcer is unusually large, very painful, or bleeding
• You suspect a dental cause – e.g. sharp filling, denture problem, or orthodontic appliance causing irritation

Final Thoughts

Mouth ulcers are a common part of life for many people – and while they’re usually harmless, they can still be frustrating and painful. The good news is that for most people, simple care, gentle oral hygiene, a healthy diet and a bit of caution + time is all it takes to heal them.

If you’re ever unsure or you suffer from frequent or persistent mouth ulcers, don’t suffer in silence – get in touch with us at John Miller Dental Practice. We’re here to help you find relief, get to the root cause, and keep your mouth healthy and comfortable.

Take care of your smile – and remember: a small ulcer doesn’t have to mean big trouble.