Dental Abscess: Symptoms, Causes and Treatments

June 21, 2016 at 2:29 PM

Written by Christian Nordqvist

A dental abscess, or tooth abscess, is an accumulation of pus that forms inside the teeth or gums.

The abscess typically originates from a bacterial infection, often one that has accumulated in the soft pulp of the tooth.

Bacteria exist in plaque, a by-product of food, saliva and bacteria in the mouth which sticks to the teeth and damages them, as well as the gums.
If the plaque is not removed by regular and proper tooth brushing and flossing the bacteria may spread within the soft tissue inside the tooth or gums, eventually resulting in an abscess.

Contents of this article:

1. Symptoms and causes of dental abscesses
2. Treatments and complications of dental abscesses

Fast facts on dental abscesses

Here are some key points about dental abscesses. More detail and supporting information is in the main article.

  • There are three types of dental abscess: gingival, periodontal and periapical
  • Symptoms of dental abscesses include pain, a bad taste in the mouth and fever
  • Dental abscesses are caused by a bacterial infection
  • If the symptoms of a dental abscess appear, the individual should visit a dentist immediately 
  • Treatment for an abscess may involve root canal surgery
  • If a dental abscess recurs after treatment, the tooth may be extracted
  • To minimize pain, it is best to avoid cold drinks and food and use a softer brush
  • If untreated, an abscess can lead to worse conditions such as cysts or maxillary sinusitis.


What is a dental abscess?
There are three types of dental abscess:

  1. Gingival abscess - the abscess is only in the gum tissue and does not affect the tooth or the periodontal ligament.
  2. Periodontal abscess - this abscess starts in the supporting bone tissue structures of the teeth.
  3. Periapical abscess - this abscess commences in the soft pulp of the tooth.

A dental abscess usually requires treatment; otherwise it can worsen and result in the destruction of bone tissue.


dental_abscess.jpgSymptoms of a dental abscess
Signs and symptoms of a dental abscess include:

  • Pain in the affected area when biting
  • Touching the affected area may be painful
  • Sensitivity to cold or hot food and liquids
  • A foul taste in the patient's mouth
  • Fever
  • General malaise (the patient feels generally unwell)
  • Trismus - the patient finds it harder to open his/her mouth
  • Dysphagia - swallowing difficulties
  • Insomnia.

The main symptom of a dental abscess is pain. This may be a throbbing pain, and is often intense. The pain usually starts suddenly, and becomes more intense over the subsequent hours or days. In some cases the pain may radiate to the ear, jawbone and neck.

Causes of a dental abscess

A dental abscess in most cases is a complication of a dental infection. Bacteria, often bacteria present in plaque, infect and make their way into a tooth.

Periapical abscess

Bacteria enter the tooth through tiny holes caused by tooth decay (caries) that form in the tooth enamel (hard outer layer of the tooth). The caries eventually break down the softer layer of tissue under the enamel, called dentine. If the decay continues, the hole will eventually penetrate the soft inner pulp of the tooth - infection of the pulp is called pulpitis.

As the pulpitis progresses the bacteria make their way to the bone that surrounds and supports the tooth, called the alveolar bone, and a periapical abscess is formed.


Periodontal abscess

When bacteria which are present in plaque infect the gums the patient has periodontitis. The gums become inflamed, which can make the periodontal ligament (tissue surrounding the root of the tooth) separate from the base of the tooth.

A periodontal pocket, a tiny gap, is formed when the periodontal ligament separates from the root. The pocket gets dirty easily and is very hard to keep clean. As bacteria build up in the periodontal pocket, periodontal abscess is formed.

Patients can develop periodontal abscesses as a result of a dental procedure which accidentally resulted in periodontal pockets. Also, the use of antibiotics in untreated periodontitis, which can mask the symptoms of an abscess, can result in a periodontal abscess. Sometimes gum damage can lead to periodontal abscesses, even if no periodontitis is present.

Dental abscess symptoms? What to do

Any person with symptoms linked to a dental abscess should see a dentist immediately. Dental abscesses are easily diagnosed by a qualified dentist. In the UK the National Health Service (NHS) advises people to visit either their usual registered dentist, a local Dental Access Centre, or the emergency department of their local general hospital.

People who have swallowing and/or breathing problems should go straight to the emergency department of their local hospital.

If for some reason you cannot get to a dentist immediately you could visit your GP (general practitioner, primary care physician). A doctor cannot treat an abscess, but he/she may prescribe medication and advise on self-care and pain management, and is also likely to know the fastest way of getting emergency treatment, if required.


Treatments for a dental abscess

 The only person who can effectively treat a dental abscess is a dentist. Treatment may involve typical dental procedures, and in some occasional surgery.

Incision - the abscess needs to be cut out (incised) and the pus, which contains bacteria, drained away. The patient will be given a local anesthetic.

Treating a periapical abscess - root canal treatment will be used to remove the abscess. A drill is used to bore a hole into the dead tooth so that the pus can come out. Any damaged tissue will be removed from the pulp. A root filling is then inserted into the space to prevent subsequent infections.

Treating a periodontal abscess - the abscess will be drained and the periodontal pocket cleaned. The surfaces of the root of the tooth will then be smoothed out by scaling and smoothing (planing) below the gum line. This helps the tooth heal and prevents further infections from occurring.


surgery_dental_abscess.jpgSurgery for dental abscesses

Patients with a periapical abscess and a recurring infection may need to have diseased tissue surgically removed. This will be done by an oral surgeon.

Patients with a periodontal abscess and a recurring infection may have to have their gum tissue reshaped and the periodontal pocket removed. This procedure will be performed by an oral surgeon.

If the dental abscess recurs, even after surgery, the tooth may be extracted (taken out).


 Treatment for pain

OTC (over-the-counter, no prescription required) painkillers (analgesics) may help reduce the pain while the patient is waiting for treatment. It is important to follow the information on the packet carefully. Painkillers are only there for pain reduction, they cannot replace the visit to a dentist.

Aspirin, ibuprofen or Tylenol (paracetamol) are effective painkillers. However, some are unsuitable for certain types of patients (read below):

  • Ibuprofen and asthma
  • if you are asthmatic do not take ibuprofen. - Ibuprofen and stomach ulcers - do not take ibuprofen if you have, or ever had stomach ulcers.
  • Aspirin and children - do not give aspirin to children under 16 years of age.
  • Aspirin and pregnancy and breastfeeding - do not take aspirin if you are pregnant or breastfeeding.

Things you can do yourself

  • Avoid cold foods and drinks
  • Avoid hot foods and drinks
  • Moderately cool foods, chewed on the "good" side of your mouth will probably be less painful
  • Do not floss around the affected area
  • Use a very soft toothbrush.


Antibiotics may be prescribed to prevent the infection from spreading, and may be taken together with painkillers. Examples of antibiotics include amoxicillin or metronidazole. In no way should antibiotics be seen as a way of substituting treatment with a dentist, or postponing treatment.


Complications of a dental abscess

In the vast majority of cases, complications only occur if the abscess is left untreated. However, complications can occur, even after seemingly effective treatment, but this is very rare. Possible complications include:

Dental cysts - a fluid-filled cavity may develop at the bottom of the root of the tooth if the abscess is not treated. This is called a dental cyst. There is a significant risk that the cyst will become infected. If this happens the patient will need antibiotics, and possibly surgery.

Osteomyelitis - the bacteria in the abscess gets into the bloodstream and infects the bone. The patient will experience an elevated body temperature, severe pain in the affected bone, and possibly nausea. Typically, the affected bone will be near the site of the abscess; however, as it may have spread into the bloodstream any bone in the body may be affected. Treatment involves either oral or intravenous antibiotics.

Cavernous sinus thrombosis - the spread of bacteria causes a blood clot to form at the cavernous sinus - a large vein at the base of the brain. Cavernous sinus thrombosis is treated with antibiotics, and sometimes surgery to drain the sinus. In some cases the condition can be fatal. This is a very rare complication.

Ludwig's angina - this is an infection of the floor of the mouth when the dental abscess bacteria spread. There is swelling and intense pain under the tongue and in the neck. In severe cases the patient may find it hard to breathe. Ludwig's angina is a potentially fatal condition. Patients are treated with antibiotics. In severe cases a tracheostomy (procedure to open the airway) is performed if there are breathing problems.

Maxillary sinusitis - the bacteria spread into small spaces behind the cheekbones, called the maxillary sinuses. This is not a serious condition, but can be painful, and the patient may develop a fever and have tender cheeks. Sometimes the conditions resolves on its own. Depending on the severity, the doctor may prescribe antibiotics.