What Is a Sinus Tract (Dental Fistula)?

Have you ever noticed a small pimple-like bump on your gum that sometimes drains pus or comes and goes? This is often a sinus tract, also known as a dental fistula. It is your body’s way of dealing with an infection inside a tooth. A sinus tract is not the infection itself, it’s simply a drainage pathway. The real problem lies inside the tooth.

Why Does a Sinus Tract Happen?

Inside every tooth, there is a nerve and blood supply called the pulp. When this pulp becomes infected usually because of:

1. Deep decay (cavity)
2. Cracks or fractures
3. Old leaking fillings
4. Trauma from an accident … it leads to a bacterial infection inside the tooth. Your body tries to fight this infection by pushing it out, and the infection looks for the easiest way to escape, forming a small tunnel that opens on the gum, This tunnel is what we see as a sinus tract.

Common Signs You May Notice

1. A small bump on the gum near a tooth
2. Sometimes the bump drains fluid or pus
3. It may not hurt (because it’s draining!)
4. The area may swell slightly
5. You may have had pain in the past, which went away later, this is why lack of pain does NOT mean the tooth is healthy.

How Do We Diagnose a Sinus Tract?

Your dentist will: Do a clinical examination of the gums and teeth. Take a dental X-ray to locate the source of infection. Sometimes use a small flexible point to trace the tract on the X-ray and identify which tooth is involved.

Treatment Options:

The key to treating a sinus tract is to treat the source of the infection, not just the bump.

1. Root Canal Treatment

If the tooth can be saved, we clean out the infected nerve and bacteria from inside the tooth and seal it. Once the infection heals, the sinus tract disappears on its own usually within 1–2 weeks.

2. Re-treatment of Old Root Canal

If the tooth had a previous root canal that failed, we may need to redo it.

3. Extraction

If the tooth is too damaged or cannot be restored, removing it will allow the infection to heal completely.

Do Antibiotics Help?

Antibiotics alone will not solve the problem. They may temporarily reduce swelling, but the sinus tract will return unless the infected tooth is treated.

What Happens After Treatment?

1. The sinus tract will slowly shrink and close
2. No surgery is usually needed to remove it
3. The gum returns to normal appearance
4. Follow-up X-rays are taken to confirm healing

Key Takeaway:

A sinus tract is a sign of a chronic infection inside the tooth even if there’s no pain. Treating the source (usually with root canal therapy) is the only way to heal it permanently. If you notice a bump on your gums that keeps coming back, don’t ignore it your tooth is trying to tell you something.