Overview

Often you may find a mouth ulcer after a dental treatment and may find it painful and irritating. The pain can increase during speech and chewing and can be very frustrating. These ulcers may occur as a result of some traumatic injury to the oral soft tissues and may heal on their own. This article aims to provide insight into the mouth ulcers that appear after dental treatment, the main causes and their management.

What are mouth ulcers?

Mouth ulcers are painful conditions in the oral mucosa and can occur on their own or due to some underlying conditions. Mouth ulcers are also called canker sores. They may cause difficulty in speaking, chewing, and eating.¹

Mouth ulcers that occur after a dental procedure are usually small, but sometimes may grow up to 1 inch in diameter. They are seen as a persistent defect in the integrity of the epithelium and connective tissue of the mouth resulting in a crater-like appearance.²  

There are different types of mouth ulcers:

• Traumatic ulcers
• Recurrent aphthous ulcers
• Herpetic ulcers
• Ulcers due to virus infection
• Behcet's disease

The mouth ulcer that develops after a dental procedure is a traumatic ulcer. It occurs due to some traumatic injuries to the mucosa. They can be due to a mechanical damage from the dental instruments or chemical burns from the medications used. They are most common on the lips, tongue, and cheek mucosa. The traumatic ulcers are seen as raised, reddish, with a yellowish-white border. On the lips, they may have a crusted appearance. They become painless in three days and usually heal within 10 days.³ The factors that cause a mouth ulcer after a dental procedure may vary. 

What are the causes of mouth ulcers after dental procedures?

Physical trauma

• The patient may cause an injury by accidentally biting on the lips or cheeks while on local anaesthesia⁴
• Dental tools like airotors and other sharp instruments can accidentally cause trauma to the mucosa⁴
• The edges of the braces are often sharp and may cause a minor injury⁴
• Sharp edges of the dentures can also cause small injuries, leading to ulcers⁴

Stress on oral tissue

• Extensive dental work or improper fitting of the dentures or other dental appliances can stress the tissue, leading to ulcers

Chemical irritants

• Certain chemicals used in dental treatment like eugenol, formocresol, sodium hypochlorite, and monomers from dental resins can cause ulcers⁵
• Liquid agents are difficult to manipulate and may overflow and cause irritation to the oral tissues
• Certain mouthwashes and other oral care products that contain high alcohol content can also irritate the oral mucosa and cause ulcers⁶
• Some people may have an allergy to some filling materials like amalgam and may develop oral ulcers

Thermal burns

• Sometimes a heated thermal instrument can accidentally cause a thermal burn resulting in an ulcer in the oral mucosa⁴

Immune response

• The body’s immune response to dental surgery or foreign objects in the mouth may also lead to ulcers 

What dental procedures can trigger mouth ulcers?

• Root canal treatment involves the use of sharp instruments and chemical agents that may trigger a mouth ulcer
• Braces’ sharp edges may cause minor injuries and ulcers
• Tooth removal 
• Dentures’ sharp edges or over-extended edges may cause ulcers
• Dental cleaning
• Dental injection 
• Wisdom tooth removal

What are the symptoms to watch for?

• Pain and discomfort: although painful, the mouth ulcers heal on their own within 7 to 10 days without causing any problem. When a mouth ulcer starts forming, you may feel a tingling, burning sensation or a rough feeling. Spicy, acidic foods like bread crumbs may increase the pain. Pain may also increase during chewing and speaking⁶
• Redness and swelling: the mouth ulcers usually appear as round spots with raised edges. The mucosa in the region may show minor swelling
• Delayed healing: if the ulcer is not healing, it could be due to some other underlying conditions, and may require medical help. If an ulcer does not heal within 2 weeks, a biopsy should be done to make sure there is no underlying fungal infection or carcinoma

Home remedies and self-care tips

Saltwater rinses

Rinse your mouth with warm salt water. It will help to keep the area clean and prevent infection. It also helps to soothe the ulcer and promote the healing process.

Avoiding irritants

Avoid spicy, acidic or sharp food that may irritate the ulcer. It helps to speed up the healing and reduce pain and recurrence. 

Ice packs

Applying ice packs 10-15 minutes daily can help to reduce inflammation and pain.

Over-the-counter solutions

Some over-the-counter medications like gels, mouth rinses, or lozenges can help to reduce the pain. A pharmacist can help you speed up the healing, reduce pain and prevent infection by recommending an antimicrobial mouthwash, a painkilling tablet, mouthwash, gel or spray, corticosteroid lozenges or a salt (saline) mouthwash.

Maintaining oral hygiene

Use a soft bristle toothbrush with gentle brushing. Avoid flossing to prevent further irritation.

Stress management

Stress is one of the factors that could exacerbate ulcers.⁷ Stress and anxiety during a dental procedure can also trigger mouth ulcers in some. Avoid taking unnecessary stress. Go for a walk, listen to good music, or try meditation techniques to reduce stress.

What to do and what not to do?

The NHS provides the following recommendations to help with mouth ulcers: 

When to seek professional help

Persistent ulcers

If you find any ulcers that is not healing within 2 to 3 weeks it may require a dentist's attention.

Signs of infection

If there are any symptoms, like pus, fever, bleeding, or severe swelling, seek medical help.

Recurrent ulcer

Frequent ulcers without any other causes may indicate an underlying health issue that needs investigation.

Treatment

Usually, mouth ulcers resolve on their own and the treatment is symptomatic. For painful ulcers, fluocinonide or triamcinolone acetonide ointments are prescribed. It can relieve the pain and make healing faster.⁴

FAQs

Can dental work cause mouth ulcers?

Mouth ulcers may be triggered after some dental procedures, mainly due to the minor injuries that may occur during the procedure or due to stress.

How do you treat mouth sores after dental work?

Mouth ulcers heal on their own generally within 10 days. Using salt water solution, gels and lozenges containing painkillers or steroids may help to reduce the pain and improve healing.

Why do I get mouth ulcers after a teeth cleaning?

Canker sores after a teeth cleaning can be due to some minor injuries that occur during the procedure and may resolve on their own.

Is it normal to get mouth ulcers after tooth extraction?

It is normal to get mouth ulcers after tooth extraction because of some minor injuries, stress, or because of biting of the lips and tongue after local anaesthesia during the procedure.

Which vitamin deficiency causes mouth ulcers?

Iron or vitamin deficiency can cause mouth ulcers.

Summary

Mouth ulcers that occur after dental treatment are quite common, usually after procedures like root canal treatment, removal of teeth, braces, etc. These ulcers are usually painful and swollen. They appear as a whitish spot with a raised border and heal on their own. The treatment is generally symptomatic, with painkillers, gels, mouthwashes, or steroids. If the ulcers show delayed healing or any signs of infection, it may require a dentist’s intervention. With proper care, mouth ulcers are usually manageable and preventable. If needed, seek professional help.