A dental crown is a custom-made cap placed over a damaged or weakened tooth to restore its shape, size, strength, and appearance. It completely encases the visible portion of the tooth above the gum line, providing a protective barrier. While the crown itself is an inert material that cannot decay or become infected, the natural tooth structure, root, or surrounding gum tissue beneath it remains susceptible to bacterial infection. Recognizing the signs of an infection developing in this area is important for securing timely treatment.
Reasons an Infection Develops Under a Crown
Infections occur when bacteria infiltrate the space between the crown and the underlying tooth or gum tissue. A common cause is recurrent dental decay, where new cavities form at the crown margin. This allows bacteria to penetrate the tooth’s inner pulp, often happening if the crown does not create a perfect seal against the tooth structure.
An ill-fitting crown or one with an open margin can create microscopic gaps that trap plaque and food debris, harboring bacteria. Physical trauma or excessive wear, such as teeth grinding, can also cause a crack in the crown or underlying tooth, providing a pathway for bacteria. If the tooth required a root canal before the crown was placed, failure of the initial treatment can lead to reinfection years later.
Identifying the Symptoms of a Crown Infection
The most direct sign of a problem is persistent discomfort or pain, manifesting as a dull ache or a sharp, throbbing sensation around the crowned tooth. This pain often intensifies when chewing or applying pressure, indicating potential inflammation or infection of the dental pulp. Heightened sensitivity to hot or cold temperatures that lingers long after the stimulus is removed suggests the infection has reached the nerve.
Visible changes in the gum tissue are indicators of an underlying infection, such as localized swelling, redness, or tenderness surrounding the crown. In advanced cases, an abscess may form, appearing as a small, pimple-like bump on the gum that may release a foul-tasting discharge or pus. A persistent unpleasant taste or bad breath that does not improve with routine oral hygiene can also signal active bacterial drainage from the infection site.
A loose crown, while not an infection symptom itself, is a precursor because a compromised seal provides an entryway for bacteria. Systemic symptoms, such as fever or generalized fatigue, may accompany a severe infection. This indicates that the bacterial presence is significant or beginning to spread beyond the local area.
Immediate Steps and Professional Treatment
If symptoms of infection are noticed, contact a dentist promptly, as home remedies cannot resolve the bacterial infection. Until the dental appointment, over-the-counter anti-inflammatory pain relievers, such as ibuprofen, can help manage discomfort and localized swelling. Rinsing the mouth with a warm saltwater solution several times a day can also soothe inflamed tissues and keep the area clean.
During the professional visit, the dentist will confirm the infection through a physical examination, percussion testing, and dental X-rays. These tests reveal decay beneath the crown or evidence of an abscess in the bone. Treatment is determined by the severity of the infection; for infections involving the tooth’s nerve, root canal therapy is commonly performed through the existing crown to clean and seal the infected tissue.
If the crown is poorly fitted or has significant decay beneath it, the crown may need to be removed to properly treat the underlying tooth structure. Antibiotics may be prescribed to control the spread of the bacterial infection, though they are usually not a standalone cure for the underlying problem. Extraction is necessary only in rare and severe cases where the tooth structure is extensively damaged or the infection is uncontrollable.