Dental abscess

A dental abscess is a collection of pus that forms in your teeth or gums as a result of a bacterial infection.

Information written and reviewed by Certified Doctors.

Contents

Introduction

A dental abscess is a collection of pus that forms in your teeth or gums as a result of a bacterial infection.

The main symptom of a dental abscess is a severe, throbbing pain at the site of the abscess. The pain usually comes on suddenly and then gets gradually worse over a few hours or a few days.

Read more about the symptoms of a dental abscess.

Types and causes of dental abscesses

There are two types of dental abscess:

  • periapical abscess – where bacteria infect the inside of the tooth (this is the most common type of dental abscess)
  • periodontal abscess – where bacteria infect the gums

Both types of dental abscess are caused when bacteria builds up inside your mouth. This usually occurs due to a combination of:

  • poor dental hygiene – not cleaning your teeth and gums properly and regularly (find out how to brush and floss your teeth)
  • consuming lots of sugary or starchy food and drink – the carbohydrates in these types of food and drink encourage bacteria to grow

Read more about the causes of a dental abscess.

Treating dental abscesses

You should make an appointment with a dentist as soon as possible if you think you may have a dental abscess.

There is little your doctor can do, other than recommend painkillers, such as ibuprofen or paracetamol, to help relieve the pain. You can get these yourself from your local pharmacist.

Your dentist will be able to drain away the pus from the abscess and, if necessary, remove any teeth that have been damaged by the infection.

This type of treatment should not be too painful because local anaesthetic will be used to numb the affected area of your mouth.

Unlike some other types of infection, a dental abscess will not get better on its own and must be treated by a dentist. With appropriate treatment, the bacterial infection that causes a dental abscess can usually be successfully cured.

Read more about how a dental abscess is treated.

Complications of dental abscesses

It is rare for complications to develop as a result of a dental abscess, but they can be serious if they do occur. For example, the infection may spread to nearby bone (osteomyelitis).

Read more about the complications of a dental abscess.

Emergency treatment

If you have severe pain, you may need emergency out-of-hours dental treatment.

Depending on your individual circumstances, you may have to pay a fee for your treatment.

Symptoms

The main symptom of a dental abscess is an intense, throbbing pain in your affected tooth or area of gum.

The pain usually comes on suddenly and may gradually get worse over a few hours to a few days.

Sometimes, the pain may spread to your ear, lower jaw and neck on the same side as the affected tooth.

Other symptoms

Other symptoms of a dental abscess can include:

  • tenderness of your tooth and surrounding area
  • sensitivity to very hot or cold food and drink
  • an unpleasant taste in your mouth
  • a general feeling of being unwell
  • difficulty opening your mouth
  • dysphagia (difficulty swallowing)
  • disturbed sleep

When to seek immediate medical help

The following symptoms can be a sign of the infection spreading to other parts of your body:

  • swelling in your face
  • a high temperature (fever) of 38°C (100.4°F) or above
  • severe pain that does not respond to treatment with painkillers
  • breathing difficulties

If you develop any of these symptoms and you are not due to see a dentist straight away, you will need to access NHS emergency dental services. In this situation, you can call:

  • your dentist, who should have an answerphone message with details of how to access out-of-hours dental treatment
  • the helpline of your local primary care trust (PCT) – you can use the find services directory to find your local PCT

Alternatively, you could visit the accident and emergency (A&E) department of your local hospital.

Causes

A dental abscess occurs when bacteria infect and spread inside a tooth or your gums.

Your mouth is full of bacteria, which combine with small particles of food and saliva to form a sticky film called plaque, which builds up on your teeth.

Eating and drinking food and drink high in carbohydrates (sugary or starchy) causes the bacteria in plaque to turn the carbohydrates into the energy they need to reproduce. Acid is also produced.

The combination of bacteria and excess acid can lead to the formation of a dental abscess. This can either occur when bacteria spread into:

  • the centre of a tooth (the pulp) through tiny holes in the tooth (dental caries) that are caused by the excess amount of acid – this is known as a periapical abscess and it is the most common type of dental abscess
  • an area of your gums underneath a tooth – this is known as a periodontal abscess

Periapical abscesses

When a periapical abscess develops, plaque bacteria infect your tooth as a result of dental caries (tiny holes caused by tooth decay) that form in the hard outer layer of your tooth (the enamel).

Dental caries break down the enamel and the softer layer of tissue underneath (dentine) and eventually reach the centre of your tooth (pulp). This is known as pulpitis. The dental pulp in the middle of the tooth dies and the pulp chamber becomes infected.

The bacteria continue to infect the pulp until it reaches the bone that surrounds and supports your tooth (alveolar bone), where the periapical abscess forms.

Periodontal abscesses

A periodontal abscess occurs when plaque bacteria affect your gums, causing severe gum disease (also known as periodontitis).

Periodontitis causes inflammation (redness and swelling) in your gums, which can make the tissue surrounding the root of your tooth separate from the base of your tooth.

The separation creates a tiny gap called a periodontal pocket, which allows bacteria to enter and spread and can be very difficult to keep clean.

The periodontal abscess is formed by the build-up of bacteria in the periodontal pocket. A periodontal abscess may also occur as a result of:

  • dental procedures that create accidental periodontal pockets
  • the use of antibiotics in untreated periodontitis, which can mask the beginnings of an abscess
  • gum damage, even if you do not have periodontitis

Risk factors

Risk factors for a dental abscess include:

  • poor oral hygiene – if you do not brush your teeth and floss between them regularly, your risk of developing a dental abscess is increased
  • having a diet high in sweet and sticky food and drink – such as chocolate, sweets, sugar and fizzy drinks and/or starchy foods, such as crisps, white bread, pretzels and biscuits
  • having a weakened immune system – this may be due to having an underlying health condition, such as diabetes, or the side effects of treatments such as steroid medication (corticosteroids) or chemotherapy

Diagnosis

If you think that you may have a dental abscess, you must see a dentist as soon as possible.

Your dentist will carry out some tests to determine whether your symptoms are being caused by a dental abscess. For example, they may:

  • tap on the affected tooth or area of gum – if infection is present, your tooth or gum will be sensitive to any pressure
  • examine your gums – an infection will usually cause an area of your gums to become red and swollen
  • take an X-ray of the affected area to help assess the spread of infection

In some cases, your dentist may be able to confirm a diagnosis by simply asking you about your symptoms.

Referral

Your dentist may refer you for treatment in hospital if you have a dental abscess and you:

  • are feeling unwell with a high temperature, a rapid pulse rate or low blood pressure (hypotension) and rapid breathing
  • are in severe pain despite taking painkillers
  • have a spreading facial infection
  • have a weakened immune system (for example, because you are having treatment such as chemotherapy)

Treatment

The only way to cure a dental abscess is with dental treatment.

Your doctor will be able to advise you, but they cannot provide the treatment needed to cure an abscess.

Your dentist will treat your abscess using dental procedures and, in some cases, surgery (see below).

Painkillers

A dental abscess can be very painful, but you can use over-the-counter painkillers from your local pharmacy to control the pain while you are waiting for dental treatment.

Ibuprofen is the preferred painkiller for dental abscesses, but if you are unable to take ibuprofen for medical reasons, you can take paracetamol instead.

If one painkiller fails to relieve the pain, taking both paracetamol and ibuprofen at the same time can often be effective (this is safe for adults, but not for children under 16 years of age).

However, you should make sure you leave six hours before taking another combined dose.

Also, always read and follow the information on the packet about how much to take and how often, and do not exceed the maximum stated dose.

Accidental overdoses have been reported in people who take too many painkillers when trying to relieve the pain of a dental abscess.

Painkillers cannot treat or cure a dental abscess, so they should not be used to delay dental treatment.

Follow the advice below to take painkillers safely:

  • do not take ibuprofen if you are asthmatic or if you have a stomach ulcer, or you have had one in the past
  • do not take more than one painkiller at the same time without first checking with your doctor or pharmacist; this can be dangerous because many over-the-counter products contain similar painkillers and it is possible to overdose when combining products
  • ibuprofen and paracetamol are both available as liquid preparations for children
  • aspirin is not suitable for children under 16 years of age
  • if you are pregnant or breastfeeding, you should take paracetamol

Self care

Other self care techniques that can help include:

  • avoid anything that makes the pain worse, such as hot or cold foods or cold air
  • holding cooled water or crushed ice around the tooth can sometimes ease the pain
  • the pain can often feel worse when you are lying flat, so lying propped up may help ease pain

Dental treatment

The first and most important step in treating a dental abscess is to cut out the abscess and drain away the pus containing the infectious bacteria.

Your dentist will carry this out under local anaesthetic. This means you will be awake throughout the procedure, but the affected area will be numb so you will feel little to no pain.

If the abscess is inside one of your teeth (a periapical abscess), root canal treatment will usually be recommended. This involves drilling into the affected tooth to release the pus and removing any damaged tissue from the centre (pulp). A filling will then be inserted into the space to prevent further infection.

If there is a pocket of pus inside an area of gum (a periodontal abscess), your dentist will drain the pus and clean out the pocket. They will then smooth out the surfaces of the root of your tooth by filing below your gum line to help your tooth heal and prevent further infection.

Antibiotics

Antibiotics are not routinely prescribed to treat dental abscess because:

  • draining the abscess is a more effective treatment
  • using antibiotics to treat non-serious infections makes them less effective at treating more serious infections (this is known as antibiotic resistance)

Antibiotics are usually only required if:

  • there are signs that the infection is spreading, such as swelling of your face or neck
  • you have a weakened immune system

If antibiotics are required, an antibiotic called amoxicillin is usually recommended. If you are allergic to amoxicillin, which is a type of penicillin, metronidazole can usually be prescribed as a precaution.

Reoccurring infection

If you have a periapical abscess and your infection reoccurs, you may need to be referred to an oral surgeon who will surgically remove any further diseased tissue.

If you have a periodontal abscess and your infection reoccurs, you may be referred to an oral surgeon who will be able to reshape your gum tissue to permanently remove the periodontal pocket.

In some cases, a dental abscess infection can reoccur even after dental and surgical procedures. If this happens, or if your tooth is severely broken down, it may need to be removed altogether (extracted).

Complications

With appropriate dental treatment, a dental abscess can usually be easily cured. However, in rare cases, complications can occur.

Most complications arise due to the spread of the bacterial infection when an abscess is left untreated. Some possible complications are outlined below.

Dental cysts

If a dental abscess is left untreated, a fluid-filled cavity may develop at the bottom of the root of your tooth. This is known as a dental cyst.

If a cyst becomes infected, treatment with antibiotics may be needed. A dental cyst can be surgically removed under local anaesthetic (where the affected area is numbed).

Osteomyelitis

Osteomyelitis is an infection of the bone. It is caused by the bacteria in a dental abscess spreading through your bloodstream.

Osteomyelitis can cause symptoms such as fever, nausea (feeling sick) and severe pain in the affected bone, which can often be in the area surrounding a dental abscess.

However, as the infection is spread through your blood, it is possible for it to affect any bone in your body. Osteomyelitis can be treated by taking oral antibiotics or injecting them into a vein.

Read more osteomyelitis.

Sinusitis

Sinusitis is an infection of the small air-filled cavities inside your skull.

It is usually the cavities behind your cheekbones that can become infected as a complication of a dental abscess. These are known as the maxillary sinuses.

Symptoms of sinusitis include:

  • a blocked or runny nose
  • facial pain and tenderness
  • a high temperature (fever) of 38°C (100.4°F) or above

Sinusitis often clears up without treatment but, if necessary, antibiotics may be prescribed.

Read more about sinusitis.

Content supplied by NHS Choices