Tooth Abscess



A tooth abscess is caused by bacteria. It begins when bacteria invade and infect the tissue around a tooth. This results in pus build-up. An abscess happens when the pus is unable to drain.

Problems that allow bacteria to invade a tooth are:

  • Severe tooth decay
  • A break or crack in a tooth
  • Failed root canal treatment
  • Advanced
  • Dental trauma

Risk Factors

Things that may raise the risk of this problem are:

  • A build up of tartar beneath the gum line
  • Poor dental hygiene



Problems may be:

  • Throbbing and pain in a tooth or gum area
  • Sudden tooth pain
  • Pain when biting
  • Pain from hot or cold
  • Redness, tenderness, or swelling of the gums
  • Fever
  • Bad breath or a foul taste in the mouth
  • An open, draining sore on the gums
  • A loose tooth


Your dentist will ask about your symptoms and health history. A dental exam will be done.

Images may be taken of the tooth and surrounding bone. This can be done with x-rays .

A sample of the abscess fluid may be taken and tested.



The goal of treatment is to ease symptoms and treat the infection. Options are:


These procedures may be done to get rid of the infection:

  • Drainage—An incision is made in the abscess to allow pus to drain from it
  • Root canal—Pus and decayed tissue are removed from the inside of the tooth, then it is filled and sealed
  • Tooth removal—A tooth with severe decay or infection is removed. It can be replaced with a partial bridge, denture, or tooth implant


Medicine may be given to ease pain. Antibiotics will be given to treat the infection.


To lower the risk of this problem:

  • Use a soft-bristled toothbrush and brush with fluoride toothpaste after meals or at least twice per day.
  • Floss every day.
  • Get regular dental check-ups and teeth and gum cleanings every 6 months.

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.

Edits to original content made by Denver Health.