Short answer: A gum fistula is a pimple-like bump that appears and drains on the gum, and in most cases it is the drainage path through which a chronic infection at the root tip of a tooth that has lost its vitality opens to the outside. It may not cause pain, but it does not go away on its own. Treatment is removing the source; a root canal, a root canal retreatment if needed, root-end surgery or an extraction is usually performed, and once the source is cleared the fistula mostly closes.
A gum fistula is a small, pimple-like bump that appears on the gum, and in most cases it is the drainage path through which an ongoing infection in a tooth beneath or around the root opens to the outside. The bump bursts from time to time, leaves a salty or bad-tasting discharge, and then forms again. Because it does not cause pain, most people do not take it seriously; yet a gum fistula is a sign that the infection has found its own way out, and it is not expected to close permanently without treating the source. In this article, we explain why a fistula forms, how it is diagnosed, the treatment options, and what should and should not be done at home.
What is a gum fistula?
A gum fistula is the opening on the gum of a thin channel created by the infection in the bone to drain the pus that builds up. In everyday speech it is also called a "gum pimple," a "tooth fistula" or a "dental fistula." In medical language, this path that opens into the mouth is called a sinus tract.
A fistula is not a disease in itself but a symptom. Its source is usually a chronic infection at the root tip of a tooth that has lost its vitality. Because the pus finds an outlet, the pressure decreases; for this reason, teeth with a fistula often do not cause pain. The absence of pain does not mean the problem has gone away; it only shows that the infection is quietly continuing.
The opening of the fistula is usually seen at the level of the root of the problem tooth, on the lip or cheek side of the gum. More rarely it can open on the palate or tongue side, and very rarely on the facial skin.
What causes a gum fistula?
The most common cause of a gum fistula is the tooth nerve (pulp) becoming infected and dying after a deep cavity, a fracture or a blow, with inflammation developing at the root tip. Bacteria travel from the root canal to the root tip, a focus of infection forms in the surrounding bone, and over time this focus opens a drainage path.
- Untreated deep cavity: When a cavity reaches the nerve, the nerve becomes inflamed and can lose its vitality over time.
- Persistent infection in a tooth that has had a root canal before: A canal that could not be cleaned, a leaking filling or a root crack can cause the infection to continue. This situation may require a root canal retreatment.
- Dental trauma: A blow received years ago can cause the nerve to die silently.
- Advanced gum disease: An abscess that develops in deep gum pockets can also form a fistula on the gum.
- Baby tooth abscess in children: A fistula is quite common in decayed baby teeth and can affect the permanent tooth coming up from beneath.
A fistula can also be thought of as the chronic form of an acute dental abscess: in an acute abscess, swelling and throbbing pain come to the fore, whereas in a fistula the picture is quieter because the pus finds a way out.
What are the symptoms of a gum fistula?
The most typical symptom of a gum fistula is a small bump with a yellow-white tip that appears and disappears repeatedly at the same spot. Other findings that may accompany it are:
- A salty, bitter or bad-tasting discharge that comes when the bump is pressed or on its own
- A persistent bad smell or taste in the mouth
- Darkening in the color of the affected tooth
- Mild sensitivity when chewing or a feeling that the tooth is "raised"
- Sometimes no pain at all
If there is fever, swelling that spreads in the face or neck, or difficulty swallowing or opening the mouth, the situation is no longer a quiet fistula; you need to see a dentist or go to the emergency room the same day.
How is a gum fistula diagnosed?
Which tooth a gum fistula comes from is determined by an exam and an X-ray, because the opening of the fistula is not always directly above the problem tooth. The dentist evaluates the vitality of the teeth by tapping them and using methods such as a cold test, and measures the gum pockets.
One of the commonly used ways to find the source is to place a thin, flexible radiopaque material (usually a gutta-percha cone) into the opening of the fistula and take an X-ray. The material travels along the channel and shows the focus of infection. When needed, three-dimensional imaging also helps with planning.
How is a gum fistula treated?
Treatment of a gum fistula is aimed not at the fistula itself but at eliminating the infection at its source; once the source is cleaned, the fistula in most cases closes on its own. Cutting and stitching the fistula or suppressing it with medication alone is not a permanent solution.
Root canal treatment
If the source is a tooth that has lost its vitality and the tooth can be saved, the first option is generally a root canal treatment. The canals are cleaned and disinfected, medication is placed in the canal between sessions if needed, and then the canals are filled. The opening of the fistula usually dries up and closes within a few days to a few weeks.
Root canal retreatment and surgical options
If the infection continues in a tooth that has had a root canal before, retreatment of the root canal is considered. In some cases, an apical resection (root-end surgery), in which the root tip is cleaned surgically, may come up.
Tooth extraction
If the tooth cannot be saved because of a vertical root fracture, advanced bone loss or loss of structure too large to repair, extraction may be recommended. How the space of the extracted tooth will be replaced is planned separately.
When are antibiotics needed?
Antibiotics alone do not treat a fistula; if there is a spreading infection, fever or a picture that affects the general condition, they may be given by the dentist as a support to treatment. Only the examining dentist decides the type and duration of the medication.
Does a gum fistula go away on its own?
A gum fistula does not go away on its own; even though it seems to have gone when the bump bursts and subsides, it forms again within a short time because the infection at the source continues. Chronic inflammation left untreated for a long time can cause loss in the surrounding bone, affect neighboring teeth and turn into an acute abscess at a time when the body's resistance is low.
A fistula originating from a baby tooth in children should be taken seriously because it can affect the permanent tooth bud developing beneath.
What can be done at home, and what should not be done?
What can be done at home for a gum fistula is only aimed at increasing comfort until you can reach a dentist; it does not treat the source.
- Gently rinsing your mouth with warm salt water can help keep the area clean.
- Keep brushing your teeth with a soft brush and avoid irritating the area.
- Do not pierce or squeeze the bump with a needle; this can spread the infection. For details, you can look at our article on popping a tooth abscess at home.
- Do not take leftover antibiotics on your own; the symptoms are suppressed but the source remains.
- Do not place aspirin or a hot compress on the gum.
How is a gum fistula prevented?
The way to prevent a gum fistula is to catch a cavity before it reaches the nerve and to protect the teeth from blows. Brushing twice a day with fluoride toothpaste, cleaning between the teeth, reducing the frequency of sugary foods and drinks, and regular check-ups are the basic steps. For those who play sports, a mouthguard reduces the risk of trauma. If you notice a color change in a tooth that took a blow in the past, it is wise to have it checked even if there are no symptoms. For explanations of terms, you can look at our dental glossary.
When should you come in if you have a bump on your gum in Ankara?
If you have noticed a recurring bump in the same place on your gum, a salty discharge or an unexplained bad taste, it is good to plan an exam within a few days even if there is no pain; if there is swelling, fever or difficulty opening your mouth, come in without waiting. At our Park Oran polyclinic in Çankaya, we determine the source with an exam and an X-ray and explain the treatment options that suit you.
Frequently asked questions
Is a gum fistula dangerous?
Even though a fistula often does not cause pain, it shows that the infection beneath continues. If left untreated, it can cause loss in the surrounding bone and turn into an acute abscess. For this reason, an exam is recommended even when there is no pain.
When does a fistula close after a root canal?
Once the source has been cleaned successfully, the opening of the fistula in most cases dries up and closes within a few days to a few weeks. If it does not close, the dentist re-evaluates the source.
Does a gum fistula go away with antibiotics?
Antibiotics can make the bump subside temporarily but do not eliminate the infection at the source; the fistula generally forms again when the medication is stopped. The examining dentist decides whether medication is needed.
Why does a fistula appear on a tooth that has had a root canal?
A part of the canal system that could not be cleaned, a leaking filling, an opening in the crown or a root crack can cause the infection to continue. In this case, root canal retreatment or root-end surgery is considered.
My child has a fistula on a baby tooth. Should we wait if it will fall out anyway?
Waiting is not recommended, because a baby tooth fistula can affect the permanent tooth bud developing beneath. Depending on the condition of the tooth, a baby tooth root canal or an extraction and, if needed, a space maintainer is planned.
