Experiencing sharp, localized pain in a single tooth only when pressure is applied, such as biting or chewing, is a specific symptom recognized by dental professionals. This discomfort is distinct from generalized tooth sensitivity or constant, throbbing pain. The pressure from biting often acts as a diagnostic tool, exposing a deeper problem within the tooth structure, its internal nerve, or the surrounding supportive tissues. This symptom should never be ignored, as it often signals a condition requiring timely intervention to prevent further damage or tooth loss.
Tooth Fractures and Structural Compromise
One of the most common causes of pain when biting is an incomplete fracture known as Cracked Tooth Syndrome (CTS). This condition occurs when a fracture line develops, usually starting on the chewing surface, but does not fully split the tooth into separate pieces. The pain mechanism for CTS is unique: when a person bites down, the two sections of the tooth on either side of the crack slightly flex or move. This movement stimulates the nerve tissue inside the pulp chamber, resulting in a sudden, sharp jolt of pain.
The pain is often most intense when the biting force is released, as the separated segments snap back into place. Unlike a full fracture, a cracked tooth remains structurally compromised but intact, making the crack difficult to detect on standard X-rays. A similar biting pain can occur with compromised restorations like loose fillings or crowns, which create movement under pressure. This movement mimics a crack by allowing forces to irritate the underlying dentin or pulp.
Deep Decay and Internal Inflammation
Pain on biting can also originate from the pulp, the innermost chamber of the tooth containing the nerves and blood vessels. This happens when deep decay has progressed close to the pulp, causing inflammation known as pulpitis. Although the decay may not cause constant pain, the biting force transmits through the compromised dentin and enamel barrier, directly pressurizing the irritated nerve tissue.
The severity of the pulpitis is categorized by the pain response. With reversible pulpitis, the pain from biting or cold stimuli is sharp but disappears immediately after the stimulus is removed. This indicates the pulp can likely heal once the decay is removed and the tooth is filled. Conversely, irreversible pulpitis signals a severe, unrecoverable inflammation. This condition typically requires root canal therapy, as the pain may be more intense, spontaneous, or linger for minutes after a stimulus is gone.
Pain Originating in the Surrounding Tissue
Sometimes, the source of the biting pain lies outside the tooth structure, specifically in the periodontal ligament (PDL). The PDL is a thin tissue that anchors the tooth root to the jawbone, acting as a natural shock absorber. Trauma from biting down on a hard object, chronic clenching, or teeth grinding (bruxism) can inflame this ligament, sometimes referred to as a “sprained tooth.” Because the PDL is highly innervated, the inflammation makes the tooth sensitive to pressure, causing a dull or sharp ache when the tooth is pressed into its socket.
A periapical abscess, a pocket of pus from an infection at the tip of the tooth root, also causes severe pain upon biting. The pressure from chewing pushes the tooth down, compressing the inflamed tissue at the root tip against the bone, resulting in intense discomfort. A recently placed filling or restoration that is slightly “high” or uneven can cause excessive contact pressure on the tooth. This leads to pain when chewing until the restoration is adjusted to match the natural bite alignment.
Immediate Steps and Professional Assessment
If you experience pain when biting down, the most important step is to contact a dental professional immediately for an evaluation. Temporarily, avoid chewing or applying pressure to the affected side of the mouth to prevent further irritation or damage. Over-the-counter pain relievers, such as nonsteroidal anti-inflammatory drugs (NSAIDs) like ibuprofen, can help manage discomfort and reduce inflammation while you wait for your appointment.
Maintaining gentle oral hygiene around the painful area is advisable, as a clean environment can help reduce inflammation. A definitive diagnosis requires a professional assessment, which involves X-rays, thermal tests to gauge nerve response, and a specialized bite test. Since many causes of biting pain are not visible, relying on a dental professional is necessary for accurate diagnosis and appropriate treatment.