A dental fistula is a drainage channel the body creates in response to a deep-seated infection, usually originating from a tooth or surrounding gum tissue. It often appears as a small, pimple-like bump on the gums or cheek, acting as a mechanism to relieve the severe pressure of an underlying abscess. While the appearance of this lesion might be alarming, its presence signifies that the infection is attempting to drain. A dental fistula is not a disease itself but rather a sign that an untreated bacterial infection requires immediate professional attention.
Understanding the Dental Sinus Tract
The terms “dental fistula” and “dental sinus tract” are often used interchangeably in dentistry, although the latter is generally the more accurate description for this specific oral condition. Technically, a fistula connects two epithelial-lined spaces (like the mouth and the sinus), whereas a sinus tract has only one opening and ends at the site of infection. In dental cases, the body forms a sinus tract from the abscessed area deep in the jawbone to the surface of the gum or cheek.
This tract acts as a natural safety valve to manage the pressure that builds up from the collection of pus, known as an abscess. As bacteria multiply at the infection site, they produce purulent exudate, which increases pressure in the hard, unyielding bone. The body’s immune response then forces a pathway through the bone and soft tissue to the surface for drainage. The visible bump on the gum, sometimes called a gum boil or parulis, is the opening where the infection drains into the mouth.
Draining the pus often results in a dramatic reduction or even complete disappearance of the severe throbbing pain that originally signaled the infection. This temporary relief is misleading, as the source of the infection, the abscess, remains and will continue to produce pus. Patients often mistakenly believe the problem has resolved when the pain subsides. However, the sinus tract typically closes and then reopens repeatedly as the abscess refills and drains, indicating a chronic infection is still active.
Primary Causes and Associated Symptoms
Dental sinus tracts originate from two main types of dental abscesses: periapical and periodontal. The periapical abscess is the most common cause, forming at the tip of the tooth root (apex) due to deep decay or trauma. Bacteria invade the dental pulp, and once the tissue dies, they spread into the surrounding jawbone, creating an infection pocket. The resulting sinus tract channels this bone infection to the oral cavity or, occasionally, the skin of the face.
Periapical Abscess Symptoms
Symptoms preceding a periapical tract are typically severe, including an intense, throbbing toothache, sensitivity to hot and cold, and localized pain when chewing.
Periodontal Abscess Causes and Symptoms
A periodontal abscess occurs when infection develops within the gum tissues and supporting bone structures, often due to advanced gum disease (periodontitis). Bacteria accumulate in deep periodontal pockets around the tooth root, leading to inflammation and pus formation. Swelling of the gum tissue may be the first noticeable sign, sometimes preceding pain, which distinguishes it from a periapical abscess.
Common accompanying symptoms for any draining dental abscess include a bad or metallic taste in the mouth due to pus drainage, bad breath, and sometimes swelling of the jaw or face. The temporary cessation of pain once the tract begins draining is a key diagnostic clue for dentists.
Professional Treatment and Resolution
Definitive treatment for a dental sinus tract requires eliminating the underlying source of the bacterial infection, not just treating the visible opening. Diagnosis begins with a thorough clinical examination and dental X-rays to locate the abscess and assess bone loss. Dentists often insert a small, flexible, sterile material (gutta-percha point) into the tract opening until it reaches the infection deep inside. A second X-ray is then taken with the material in place, precisely tracing the tract back to the causative tooth.
Treating Periapical Abscesses
If the tooth is structurally sound, the primary treatment for a periapical abscess is Root Canal Therapy (endodontic treatment). This procedure involves cleaning out the infected pulp tissue from the root canals, disinfecting the space, and sealing the tooth to prevent re-infection. If the tooth is severely damaged by decay, fracture, or extensive bone loss, extraction is necessary to fully remove the infectious source.
Treating Periodontal Abscesses
When the sinus tract results from a periodontal abscess, treatment focuses on deep cleaning procedures like scaling and root planing. This non-surgical approach involves scraping away plaque and hardened tartar from the root surfaces below the gum line. Antibiotics may be prescribed to manage a spreading infection, but they are rarely effective as a standalone treatment. Once the underlying infection is successfully treated, the dental sinus tract naturally heals and closes, usually within a few days to two weeks.