Dental Fistula: Causes, Symptoms & Treatment Options

Key Takeaways

Symptoms

• Pimple-Like Bump: A small, raised, red, or yellowish bump on the gums (also called a gum boil) is the most common sign.
• Pus: The bump may release a pus-like substance, which can have a foul taste and cause bad breath.
• Pain: There may be pain or discomfort, though the fistula itself can sometimes be painless. The pain can radiate to the jaw, neck, or ear.
• Swelling and Redness: The area around the fistula may appear swollen and red.
• Other Symptoms: Fever and a general feeling of being unwell can also occur, especially with a more severe infection.
• Tooth Sensitivity: The affected tooth may become sensitive to heat, cold, or pressure.

Treatment Options

• Drainage: The fistula may need to be surgically drained by a dentist to release the pus.
• Antibiotics: A dentist will likely prescribe antibiotics to help clear the underlying bacterial infection.
• Root Canal Therapy: If the tooth is still viable, a root canal can remove the infected pulp and seal the tooth, eliminating the source of the infection.
• Tooth Extraction: If the tooth is too damaged to be saved, extraction may be necessary to get rid of the infection completely.
• Oral Hygiene: After treatment, maintaining excellent oral hygiene, including regular brushing and flossing, is crucial to prevent recurrence.

A dental fistula, also referred to as an oral fistula, is an unusual passage that develops between an infected area inside your mouth to the surface of the gums, skin, or cheek. To put it simply, it indicates your body is draining an underlying abscess or infection due to pressure buildup.

A small bump, which may appear to resemble a “boil on the gum,” may seem insignificant, but it is your body's way to alert you to a more significant dental concern. A fistula is suggestive of a chronic infection that will not resolve independently and will likely spread to other teeth, the jawbone, and from there, into the body.

This blog will provide insights into the causes of a dental fistula, common signs and symptoms associated with it, and dental treatment options, as well as what steps to take when you suspect you have one.

What Is a Dental Fistula?

A fistula dental or oral fistula is an abnormal connection that develops between an area of infection located inside your mouth and the surface of the gums, cheek, or skin. In essence, it is your body’s method of draining an abscess or infection underneath when pressure builds up.

What Causes a Dental Fistula?

A dental fistula doesn’t appear overnight. It forms as the result of an ongoing infection that creates pus buildup, forcing it to find an escape route through soft tissues. Here are the main causes behind it:

Untreated Tooth Decay

When tooth decay penetrates deep into the enamel and dentin, bacteria can reach the tooth pulp, the nerve-rich center of the tooth. As the infection worsens, it spreads through the root tip into surrounding tissues, creating an abscess. When pressure from pus builds up, a channel (the fistula) forms to relieve it by draining to the surface.

If left untreated, this can cause the fistula on gums to become a recurring or chronic issue.

Failed or Incomplete Dental Work

Previous dental treatments like root canals, large fillings, or crowns can sometimes fail due to hidden infection or improper sealing. Reinfection of the root canal system can lead to abscess formation and, eventually, a fistula tooth.

Even minor trauma during a procedure may leave bacteria trapped inside, allowing infection to persist and re-emerge later as a gum fistula.

Advanced Gum Disease (Periodontitis)

In severe periodontal disease, bacteria and plaque destroy the tissues that support the teeth, including the gums and bone. As these structures weaken, infection can travel deep into the roots, eventually creating a fistula in the mouth.

Gum disease-related fistulas often appear between teeth or near the gumline, and they may drain pus intermittently.

Trauma to the Tooth or Jaw

A blow to the mouth, cracked tooth, or jaw injury can create a pathway for bacteria to invade deeper tissues. Over time, this leads to infection, abscess formation, and the development of a fistula on the gum or cheek.

Such cases often appear after sports injuries, falls, or teeth grinding that compromise tooth structure.

Symptoms of a Dental Fistula

A fistula dental may show clear signs, but sometimes symptoms can be subtle, especially when pus drains regularly and relieves pressure. Here are the most common signs to look for:

A Small Bump on the Gums

A telltale sign is a small white, yellow, or reddish bump on the gums—often near the root of an infected tooth. This bump (also called a “gum boil” or parulis) is the visible exit point for pus drainage.

Pus or Fluid Discharge

You may notice pus oozing from the bump, along with an unpleasant taste or smell in your mouth. The discharge helps relieve pressure temporarily, but the underlying infection remains.

Pain or Throbbing

While some patients experience severe pain, others may have little to no discomfort if the fistula continuously drains. However, pain may flare up when the drainage pathway becomes blocked.

Swelling in Gums or Jaw

Localized swelling in the gums, face, or jaw is common around the infected tooth. In more advanced cases, the area may become tender and warm to the touch.

General Symptoms

If infection spreads, you might experience fever, fatigue, or swollen lymph nodes near the jaw or neck, signs that require urgent dental attention.

Treatment Options for a Dental Fistula

Treating a dental fistula requires addressing the source of the infection, not just the visible bump. The goal is to eliminate bacteria, allow the tissues to heal, and prevent recurrence.

Here are the main treatment options your dentist may recommend:

Antibiotics

Antibiotics are often prescribed as an initial step to control bacterial infection and reduce inflammation. However, they only offer temporary relief. Antibiotics alone cannot permanently cure a dental fistula because the underlying infection, whether from a decayed tooth or a periodontal pocket, remains. Dentists typically use antibiotics to stabilize the infection before performing definitive treatments like a root canal or extraction.

Root Canal Therapy (RCT)

When the affected tooth can be preserved, a root canal treatment is the preferred option. During this procedure, the infected pulp inside the tooth is carefully removed, and the root canals are cleaned, disinfected, and sealed. Finally, a filling and dental crown are placed to restore strength and function.

By removing the infection source, this treatment allows the surrounding tissues to heal naturally, leading to closure of the fistula over time and preventing reinfection.

Tooth Extraction

If the tooth is too damaged, fractured, or reinfected beyond repair, tooth extraction may be the best course of action. Removing the infected tooth eliminates the source of the problem and enables the fistula to heal as the infection clears.

After healing, your dentist may suggest a replacement solution, such as a dental implant, bridge, or partial denture, to maintain function and aesthetics.

Periodontal Therapy

When the cause of the fistula is advanced gum disease (periodontitis), periodontal therapy becomes essential. Treatment may involve:

• Scaling and root planing (deep cleaning) to remove plaque, tartar, and bacteria.
• Antimicrobial rinses or gels to reduce bacterial buildup.
• Laser therapy or surgery for deep periodontal pockets.

By treating the gum infection directly, the gum fistula resolves naturally, and overall gum health is restored.

Surgical Treatment (for Persistent Fistulas)

In chronic or complex cases, surgical procedures may be necessary to eliminate infection. These may include:

• Incision and drainage to release accumulated pus.
• Flap surgery to access deep-seated infections or bone defects.
• Apicoectomy, which involves removing necrotic tissue or cysts near the root tip.

Your dental specialist will determine the most appropriate surgical approach if non-surgical treatments are not effective.

How Can You Prevent Dental Fistula?

To prevent a dental fistula, it's important to maintain good oral hygiene and deal with dental issues as they arise. Here are important tips to help prevent dental fistula:

Practice Good Oral Hygiene

Brush twice every day, floss daily, and rinse with an antibacterial mouthwash to decrease the total bacteria in your mouth that may lead to infections.

Regular Dental Check-Ups

Go to your dentist every six months for cleaning and checkups. Find cavities and gum disease early to repair them before infection occurs, which causes a dental abscess or fistula.

Treat Dental Issues Right Away

Repair cavities, tooth decay, and gum disease whenever it is detected to reduce the risk of infection that could lead to an abscess or a fistula.

Avoid Dental Trauma

Help protect your teeth from damage by wearing a mouthguard while playing sports or exercising. Damage to teeth can lead to the risk of infection.

Diet

Minimize the amount of sugar in your food and drinks to reduce tooth decay and eat a balanced diet for overall dental health.

By taking preventative steps, you will reduce the risk of infection related to dental fistulas and improve your dental health.

Final Takeaways: Understanding and Treating Dental Fistula

A dental fistula is a clear indicator of an underlying oral infection that should never be ignored. While it may appear as a small bump on the gums, it often signifies deeper issues such as tooth decay, gum disease, or failed dental work. Understanding its causes, symptoms, and treatment options is essential for timely care and effective recovery. Treating the infection at its root, whether through antibiotics, root canal therapy, extraction, or periodontal treatment, ensures complete healing and prevents recurrence. Early professional intervention remains the key to maintaining long-term oral health and avoiding serious dental complications.