A dental crown is a custom-made cap placed over a damaged or weakened tooth to restore its shape, size, strength, and appearance. Although a crown is intended to protect the tooth, pain when chewing is a common symptom signaling an underlying problem. This discomfort, often a sharp jolt or a dull ache under pressure, indicates that the force of biting is aggravating a compromised structure or an inflamed nerve. Understanding the potential causes, from physical failures to internal nerve issues, is the first step toward finding relief.
Structural Causes of Crown Pain
Pain that occurs only when pressure is applied to the crowned tooth often points to an issue with the crown itself or the underlying tooth structure. A frequent cause is recurrent decay, also called secondary caries, which develops where the crown meets the natural tooth. If the crown margin (the edge of the cap) is not perfectly sealed, bacteria and food particles can leak beneath it, causing decay in the remaining tooth tissue. This process weakens the structure, and the pressure of chewing directly irritates the cavity.
An ill-fitting or leaky crown margin can also cause sensitivity and pain, even before significant decay begins. A small gap allows temperature changes and bacteria to reach the sensitive dentin and pulp, leading to intermittent pain when biting down. Another element is a fracture in the underlying tooth or the crown material, often due to heavy chewing forces or grinding habits. This is characteristic of cracked tooth syndrome, where the crack opens only when pressure is applied, causing a sudden, sharp burst of pain that quickly disappears when the bite is released.
Internal and Nerve-Related Sources of Discomfort
Discomfort that lingers or throbs, even without direct chewing, suggests a biological response within the tooth’s innermost tissues. The nerve and blood vessels inside the tooth, known as the pulp, can become inflamed (pulpitis) due to the trauma of the initial crowning procedure or progressing decay. Reversible pulpitis is a short-term sensitivity that resolves on its own. However, irreversible pulpitis involves persistent, intense inflammation that is severely aggravated by chewing pressure and requires professional intervention.
A severe infection at the root tip, known as a periapical abscess, can develop if bacteria penetrate the pulp chamber and travel through the root canals into the surrounding bone. The pressure created by the pus and inflammation intensifies when the tooth is pressed down during chewing, resulting in a deep, throbbing ache. Another element is bite misalignment, or occlusal trauma, where the crown is slightly too high and receives excessive force when the patient closes their mouth. This uneven pressure stresses the periodontal ligament, the soft tissue that holds the tooth in the socket, causing pain that feels like a bruised tooth.
Even a tooth that previously received root canal treatment can develop pain under a crown if the initial treatment failed to fully eliminate all bacteria or if a new infection arose later. This recurring infection, sometimes due to a missed canal or incomplete seal, can cause inflammation and a periapical abscess. The abscess then manifests as pain when biting down due to pressure on the ligament. The pain from these internal issues may be constant or intensify when the tooth is used to chew.
Immediate Patient Action and Professional Diagnosis
When pain under a crown begins, patients should immediately avoid chewing on the affected side to prevent further irritation or damage. Over-the-counter anti-inflammatory medications, such as ibuprofen, may help reduce the nerve and ligament inflammation until a dental appointment is secured. Patients must contact a dentist promptly, as persistent pain rarely disappears on its own.
A professional diagnosis begins with a thorough visual and manual examination, checking the crown margins, surrounding gum tissue, and the restoration’s stability. Radiographs (X-rays) are used to reveal issues invisible to the naked eye, such as decay beneath the crown, bone loss, or a developing abscess at the root tip. To pinpoint structural issues, the dentist may use articulating paper to check for high spots in the bite or an instrument like a Tooth Slooth to locate a subtle fracture. Finally, pulp testing, using thermal or electric stimuli, determines the vitality of the tooth’s nerve, differentiating between reversible sensitivity and irreversible nerve damage.
Long-Term Solutions for Crown Pain
The long-term solution depends entirely on the underlying cause identified during diagnosis. If the pain stems from a minor bite discrepancy, an occlusal adjustment is the simplest treatment. This involves a quick, precise grinding down of the crown’s surface to ensure even pressure distribution during chewing. If the crown is compromised by an ill-fitting margin or minor recurrent decay, treatment involves removing the existing crown, addressing the decay, and then fabricating and cementing a new, well-sealed crown.
If the diagnosis reveals irreversible pulpitis or a periapical abscess, the necessary procedure is root canal therapy. This process involves creating a small access hole through the crown to clean out the infected pulp and nerve tissue, eliminating the source of inflammation and infection. For teeth that have sustained an extensive vertical fracture or where infection has caused irreparable damage to the supporting bone, the only remaining option may be extraction. Extraction is considered a last resort to resolve the pain and prevent the spread of infection.