Dental Fistula - Treatment & Prevention

Clinical Content Reviewed by Dr. Jay Khorsandi, DDS
Last Modified:

Table of Contents

  1. Causes
  2. Symptoms
  3. Treatment
  4. When to Seek Help
  5. Prevention
  6. References

A dental fistula, also known as an oral fistula, is an unnatural canal that develops between two regions in the mouth. The canal connects to an abscess and drains infections from it.

An abscess refers to a pocket of pus that forms after bacteria infects a particular area inside the mouth, usually in the soft pulp of a tooth.

Bacteria present at the site grow, and surrounding tissue becomes tender, creating a pocket that fills with pus, bacteria and debris. Unchecked, the infection spreads, causing an even larger abscess.

Symptoms of an abscess include fever, pain and a sour or foul taste.

Causes and How It Forms

A fistula usually occurs when abscessed teeth or gums cause an infection. After enough time, discharge from the infection accumulates, and mounting pressure causes a fistula to connect the abscess to the gum.

Abscesses form at the root of your teeth. The most common causes of an abscess include a mouth or tooth injury, poor dental hygiene and previous dental work. Dental treatments like a root canal can lead to an abscess and, eventually, a fistula.

Fistulas also form in the mouth of someone who has chronic dry mouth or who has a diet that is consistently high in sugar. A congenital defect may also cause a fistula, although it is rare.

A fistula is rarely painful. Even if you experience minor pain, it is not constant.


Symptoms of a fistula include:

A small bump that forms on the gum (gum boil)

Pus discharges into the mouth, often accompanied by a foul taste and smell

You may not always be able to tell when a fistula is forming. Still, the symptoms of an abscess are easier to recognize:

  • Tenderness or soreness where the abscess is forming

  • Tooth sensitivity

  • Fever

  • Enlarged jaw and neck lymph nodes

  • Swelling

  • Throbbing toothache

If you have difficulty breathing or swallowing, you must seek medical attention immediately.


If a doctor or dentist determines that you have a fistula, you will need medical attention. Fistula’s almost never disappear untreated. Infections can spread uncontrolled when left untreated, and in this case it can affect your jaw bone and other parts of the mouth.

The dentist will take an X-ray of the affected area during the examination. Afterward, they will also perform an intraoral and extraoral analysis.

An endodontist may drain the pocket of infection and prescribe antibiotics to kill the bacteria that caused the infection. Depending on the severity of the fistula, the dentist may recommend a root canal or a tooth extraction.

A root canal is a dental treatment involving treatment of an infected tooth, preventing reinfection, and saving the natural tooth. During this treatment, the dentist removes the infected nerve and pulp in the root of the tooth, disinfects and cleans the inside, then fills and seals the tooth.

Dentists perform root canals under local anesthesia, which minimizes any immediate pain. But anyone who undergoes a root canal should expect swelling and discomfort for a day or two afterward. Your dentist may also recommend a crown to preserve and protect the tooth’s aesthetic and functionality.

Tooth extraction is the total removal of an infected or damaged tooth. Dentists engage this treatment when a root canal is not an option. If you have an abscess, the dentist may prescribe antibiotics first to clear the infection before the extraction.

The endodontist will also perform the procedure under local anesthesia. You will be tender and sore for a day or two. After the gum heals in a few weeks, you can discuss tooth replacement options with your dentist.

For less severe cases, one round of antibiotics and a pus draining session is enough to get rid of the fistula.

When to Seek Help

It is best to seek help immediately after you notice the fistula bump forming. Since it is rare for the fistula to go away on its own, you should seek endodontic treatment. You may notice other symptoms like fever, pain, and swelling before detecting the bump.

If you do not seek treatment immediately, you could develop complications like bone or tooth loss. On rare occasions, the infection from the abscess can seep into your bloodstream, causing sepsis. Also, seek quick medical attention if you struggle with swallowing or breathing.

If you cannot see a dentist immediately, you can take other steps to provide relief:

  • Swish and gargle warm salty water. Ensure the water is warm and not hot, as hot water will only aggravate the fistula.

  • Take over-the-counter pain medication to help with fever and swelling.

  • Apply a cold compress to the affected area several times a day to relieve pain.

  • Apply a warm compress to help increase blood circulation to the area, delivering nutrients and encouraging healing.

  • Continue with regular oral hygiene.

Even if you are certain bacteria are causing the infection, it is never a good idea to self-prescribe antibiotics. Only take them after a dentist or doctor prescribes them.


As fistulas result from diverse factors like poor hygiene, sugary diets, and injury, there is no remedy or special treatment to prevent them. To minimize your chances of developing a fistula, practice good oral hygiene, maintain a healthy diet, and visit the dentist at least twice a year.

You can prevent dental fistulas by:

  • Brushing your teeth twice daily, for at least two minutes each time. Floss once daily.

  • Use fluoridated mouthwash and toothpaste.

  • Limit sugar and acidic foods and increase your fruit and vegetable intake. Eat calcium-rich foods like dairy products, green leafy vegetables, and beans.

  • Chewing sugar-free gum to help increase saliva production and to prevent dry mouth.

  • Going for regular dental checkups to boost oral health.

If you suspect you have dental fistula, you must make a dental appointment as soon as possible. If you’ve had recent dental work done, you should make several appointments to ensure no abscess forms. Even if you do not feel any pain, but feel the presence of a fistula or abscess, seek medical attention.

Disclaimer: This article is intended to promote understanding of and knowledge about general oral health topics. It is not intended to serve as dental or other professional health advice and is not intended to be used for diagnosis or treatment of any condition or symptom. You should consult a dentist or other qualified healthcare provider with any questions you may have regarding a medical condition or treatment.