Dental abscess

What is a dental abscess?

Normal tooth

A dental abscess is a localised collection of pus in a tooth or in nearby structures. Pus is a thick fluid that usually contains white blood cells, dead tissue and germs (bacteria). The usual cause of an abscess is a bacterial infection. They are classified into two main types.

Types of dental abscess

Periapical abscess

This type of abscess starts in the centre of the tooth (the dental pulp). This is the most common type. This type of abscess usually develops as a complication of tooth decay (caries). Dental decay is very common. It damages and breaks down (erodes) the protective layers of the tooth (the enamel and dentine). The damage to the tooth allows bacteria to invade the pulp to cause an infection.

An infection in the pulp can progress to form an abscess. Sometimes a periapical abscess develops if the nerve to the tooth dies for any reason. For example, from injury. The dead tissue inside a tooth is more prone to infection.

Periodontal abscess

This type of abscess starts in the supporting structures of the teeth, such as the periodontium which is between the tooth and the gum. It most commonly develops as a complication of gum disease (periodontal disease), which is infection or inflammation of the tissues that surround the teeth.

Gum disease often causes the gum to become slightly detached from the tooth. This causes pockets to form which may get filled with bacteria and progress to form an abscess. A periodontal abscess may also develop as a complication of injury to the gums or periodontium. A periodontal abscess is sometimes called a gum boil as the abscess causes a swelling to develop next to a tooth.

Dental abscess symptoms

Symptoms typically include one or more of the following:

• Pain (toothache) which can quickly become worse. It can be severe and throbbing.

• Swelling of the gum, which can be tender.

• Swelling of the face. The skin over an abscess may become red and inflamed.

• The affected tooth may become tender to touch, and may even become loose.

• High temperature (fever) and feeling generally unwell.

• In severe cases, there may be spasm of the jaw muscles.

• Sensitivity to hot or cold temperatures.

Dental abscess treatment

Initial treatment

See a dentist as soon as possible. A dentist will normally drain the pus and this often gives great relief of symptoms. This is done either by piercing (lancing) the abscess or by drilling a small hole in the tooth to let the pus escape.

Sometimes, if the infection is not contained, an antibiotic medicine is prescribed for a few days after draining the pus to clear any remaining infection. However, in most cases an antibiotic is probably not needed once the pus is drained. A GP cannot make the decision as to whether an antibiotic is appropriate, and should not prescribe antibiotics for this - it has to be a dentist.

Further treatment

Other treatment for a dental abscess includes the following:

Root canal

Root canal treatment is normally given to treat a periapical abscess. This treatment aims to save and restore the damaged or dead inner part of a tooth (the pulp). Briefly - a dentist will drill into the dead tooth and allow pus to escape through the tooth, and then remove the dead pulpal tissue.

A root filling is then placed into the tooth to fill the space and prevent further infection. (Note: even if pain has gone with an initial emergency drainage of the pus, you are still likely to need root canal treatment. This is because the infection and abscess will almost certainly return unless the dead pulp tissue is dealt with.)

If the infection persists despite root canal treatment, the dentist may have to remove (extract) the tooth.

Draining the abscess

For a periodontal abscess the pus is usually drained. A dentist may also clean the pocket where the abscess had formed. Following this a dentist may smooth out the root surfaces of the tooth to encourage the gum to close back on to the tooth and for any pocket to disappear.

This helps to prevent a recurrence of infection. If you develop repeated periodontal abscesses you may be referred to an oral surgeon. The oral surgeon may carry out a procedure to reshape the gum tissue.

Do you need to see a doctor?

Your GP cannot do anything to help apart from recommend painkillers, which can be bought over the counter. Primary care in the UK is under unprecedented pressure and you should not ring your GP for dental problems, because it takes up a phone call or face to face appointment which could have gone to someone who the GP can help.

You may need painkillers such as paracetamol or ibuprofen until the abscess is drained and treated. These are both available over the counter. (Note: paracetamol and ibuprofen can be taken together if pain relief with either alone is not enough. Some people require stronger painkillers prescribed by a dentist)

Dental abscess causes

Dental abscesses may occur because a tooth has not properly grown out of the gum (is impacted), because there is tooth decay or gum disease, or because of an injury to the teeth, gums or mouth. They may be more common in those who are having radiotherapy or chemotherapy.

Complications of a dental abscess

Other complications are uncommon. However, they can be serious, even fatal in rare situations, for example, if the infection has spread. They include:

• Osteomyelitis - an infection of the nearby bone.

• Sinusitis - spread of infection to the nearby sinus in the face bone.

• A dental fluid-filled cavity (cyst) which may develop.

• Cavernous sinus thrombosis - this is an infection and clotting of a blood vessel in the brain. It is very serious.

• A serious, potentially life-threatening infection of the floor of the mouth. This could spread to the face, brain or neck (symptoms of serious infection are listed below).

So, the take home message is - if you have a dental abscess then you should have it treated. This is not only to relieve pain but to prevent possible serious complications. Symptoms that may indicate that a complication is developing and where you should seek medical help urgently are:

• If you feel very unwell with a high temperature.

• Having difficulty opening your mouth, swallowing or breathing.

• Having swelling of the floor of your mouth, face or jaw.

• Being in severe pain despite taking painkillers at maximum dose.

• Having a spreading infection of your face.

Complications are more likely to develop in people with diabetes and in those with a poorly functioning immune system. For example:

• People with HIV/AIDS.

• People taking chemotherapy.

• People who have had their spleen removed.

• People taking steroids.

• People with sickle cell anaemia (not sickle cell trait).

Outlook

If treated, the outlook (prognosis) is good. The pus can usually be drained and the tooth can be saved if it is not badly broken down. If left untreated, the abscess may burst on to the skin of the face or into the mouth. This may leave a channel (a sinus tract) between a persistent focus of infection and the skin or mouth, which can discharge pus from time to time.

Preventing a dental abscess

Most dental abscesses are preventable, as most are a complication of tooth decay or gum disease. Both of these can be prevented with good oral hygiene. Briefly, this means regularly brushing your teeth and flossing.

Other things that may help include:

• Using mouthwash.

• Cleaning your tongue.

• Eating a healthy diet.

• Limiting sugary drinks and foods.

• Stopping smoking (this will improve oral hygiene).

• Having a dental check-up at least once a year.

See the separate leaflet called Oral Hygiene for more details.

How to see a dentist

If you suspect that you have a dental abscess, you should see a dentist as soon as possible. To access emergency dental care:

• See your own dentist if you are registered with one; or

• Go to the Accident and Emergency department of a dental hospital (if available); or

• Go to the local Dental Access Centre (if available); or

• Dial NHS 111.

• Check the NHS Choices 'Find Dentist Services' site online (see link in Further reading below).

• If none of the above is available, go to your nearest general hospital Accident and Emergency department; for severe/urgent problems, they may refer you to a hospital oral surgeon.

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