Fistula

A fistula in dentistry, sometimes called a sinus tract or gum boil, is a small channel that forms between an area of infection (usually at the tip of a tooth root) and the surface of the gum tissue. It appears as a small, pimple-like bump on the gum that may periodically drain pus. Interestingly, because the fistula provides drainage, the patient may experience little to no pain, which can be misleading.

The underlying cause of a dental fistula is almost always a chronic infection. This could be from a tooth with a dead or dying nerve, a failed root canal, or a deep periodontal pocket. The infection creates pressure and the body forms a drainage pathway to relieve it. While the fistula itself is not dangerous, the infection causing it absolutely requires treatment. Left untreated, the infection can spread to surrounding bone and soft tissue.

From a clinical standpoint, when a fistula is found during an exam, the next step is identifying the source. This typically involves X-rays and sometimes tracing the fistula with a gutta-percha point to see which tooth it leads back to. Treatment addresses the source of infection, whether through root canal therapy, retreatment of a previous root canal, or extraction. Once the infection is resolved, the fistula usually heals on its own.