A dental abscess or tooth abscess can occur in the teeth, supporting structures of the teeth (ligaments and bones), or the gums. An abscess is a localised collection of pus most commonly caused by a bacterial infection. Tooth decay can enable bacteria to invade the dental pulp inside the tooth. An abscess at the end of the tooth (root canal) is called a periapical abscess and an abscess in the gum is called a periodontal abscess.


  • Incidence: 200.00 cases per 100,000 person-years
  • Peak incidence: 40-50 years
  • Sex ratio: 1:1
<1 1-5 6+ 16+ 30+ 40+ 50+ 60+ 70+ 80+


Risk factors
  • Poor dental hygiene: Enquire about the frequency of brushing and flossing and their diet (how much sugar they consume?)
  • Dental caries.
  • Periodontal disease.
  • Partially erupted or impacted tooth.
  • Dental trauma: Have they had previous dental procedures e.g. fillings, root canals and extractions?
  • Alcohol or drug misuse.
  • Malnutrition.
  • Immunocompromise.
  • Previous radiotherapy.
  • Medications causing a dry mouth (e.g. anticholinergics, antihistamines, and antidepressants).

Clinical features

Patients typically present with a subacute onset of:
  • Pain: typically the pain is intense and throbbing and starts suddenly and gets worse over hours to days. The pain may wake the patient from sleep and the tooth may be tender and cause pain when eating.
  • Temperature sensitivity (e.g. to hot or cold drinks).
  • Foul taste.
  • Fever.
  • General malaise.
  • Trismus (inability to open the mouth).
  • Dysphagia (in severe cases).

  • Facial swelling
  • Gum swelling
  • Altered tooth appearance (the affected tooth have signs of decay, be elevated or broken).
  • Local lymphadenopathy.
  • Gum swelling.
  • Pus may be visible (it can be intra or extra-oral).
  • If you palpate the tooth it might wobble and may well be tender.
  • The gum may also be tender or warm to palpate.
  • Signs of severe infection include signs of cardio-respiratory compromise or airway obstruction.


  • If a patient presents to their doctor with a tooth abscess a diagnosis is made on the clinical history and examination findings.
  • Patients should be encouraged to attend their dentist for definitive diagnosis and treatment unless they require emergency admission to a hospital due to severe complications or sepsis.


  • Definitive treatment can only be given by a dentist and antibiotics will not eliminate the source of infection.
  • Serious complications can occur if a patient is not treated by a dentist.
  • Antibiotics are generally not indicated in an otherwise healthy individual unless they are systemically unwell or have signs of severe infection.
  • If antibiotics are indicated or a patient is unable to attend a dentist amoxicillin or phenoxymethylpenicillin are first line (clarithromycin if there is a history of true penicillin allergy).
  • If the infection is severe or spreading, or the patient has systemic signs of infection metronidazole should also be prescribed.
  • Analgesia may be necessary: ibuprofen and paracetamol are first-line (if not contraindicated).


Complications include loss of the infected tooth, the formation of a fistula or sinus tract, or spread of infection. The spread of infection can include local structures eg maxillary sinus, osteomyelitis, cellulitis, brain abscess or generalised sepsis.