Experiencing sensitivity after a dental filling is common, but the specific symptom of pain when biting or chewing is particularly notable. This discomfort occurs because chewing places direct pressure on the filled tooth, signaling a mechanical issue or an internal reaction to the procedure. While mild sensitivity usually fades as the tooth recovers, pain upon biting often indicates a mechanical problem or inflammation that requires attention. Understanding the source of this pressure or irritation is the first step toward finding relief.
Misaligned Bite
The most frequent and easily corrected cause of pain when biting is a filling that is fractionally taller than the surrounding tooth structure, known as hyperocclusion. Even a minuscule deviation of a few micrometers can dramatically increase the force concentrated on that single spot when the jaws close. This uneven pressure causes the filled tooth to hit its opposing tooth first, disrupting the natural bite alignment.
This mechanical overload irritates the periodontal ligament, which is the tissue and fibers surrounding the tooth root that anchor it to the jawbone. When the filling is high, the ligament experiences excessive compression with every bite, leading to inflammation and soreness. This irritation is often felt as a sharp, immediate pain when chewing or a dull ache that develops over time. The pain persists because the tooth is constantly being “bumped” out of alignment, preventing the ligament from resting and healing.
Since the mouth is typically numb during the filling procedure, it can be difficult for the dentist to fully evaluate the bite accurately until the anesthesia wears off. If the tooth feels like it is hitting first or feels like a “rock in your shoe,” the filling likely needs a simple adjustment. The dentist uses special articulating paper to mark the high points of contact and then polishes the filling down, restoring even pressure. Once this mechanical stress is removed, the periodontal ligament can calm down, and the pain usually resolves within a couple of weeks.
Internal Nerve Irritation
Beyond mechanical issues, pain when biting can be a biological reaction within the tooth’s innermost soft tissue, the pulp, which contains the nerve and blood vessels. Removing decay and preparing the tooth for the filling can cause the pulp to become inflamed, a condition known as pulpitis. Biting down exacerbates this internal swelling by further compressing the irritated nerve tissue within the rigid confines of the tooth structure.
This inflammation is categorized into two types based on the nerve’s ability to recover. Reversible pulpitis is the more common and milder form, presenting as temporary sensitivity that subsides quickly after the stimulus is removed. This temporary inflammation is expected, especially with deeper fillings, and the pulp should heal completely within a few weeks.
Irreversible pulpitis signals that the inflammation is severe and the pulp is unable to heal itself. Symptoms include persistent, throbbing pain that lingers for more than a few seconds after exposure to cold or pressure. If the pain upon biting is intense and does not improve over a couple of weeks, it may indicate irreversible nerve damage, often necessitating a root canal procedure.
Potential Structural Complications
In some cases, pain upon biting is caused by a structural failure in the tooth itself, rather than a high filling or simple nerve irritation. One significant cause is Cracked Tooth Syndrome, involving a fracture extending from the chewing surface vertically toward the root. Teeth with large fillings, particularly older ones, are more susceptible because the filling material can act as a wedge, weakening the remaining tooth structure.
When biting down, pressure forces the two segments of the cracked tooth to move slightly apart, stimulating the pulp and causing brief, sharp, erratic pain. The pain is frequently felt most acutely when releasing the biting pressure, as the crack snaps back into place. Unlike the constant discomfort of a high filling, cracked tooth pain can be inconsistent and difficult to pinpoint.
Another structural concern is the fracture of a cusp, one of the pointed projections on the chewing surface, often around the edge of a filling. While a fractured cusp rarely damages the nerve directly, it can cause pain when chewing because the broken piece may flex slightly under pressure. These structural issues are challenging to diagnose but require prompt attention to prevent the crack from spreading deeper, which could compromise the tooth’s long-term survival.
When to Contact Your Dentist
Mild sensitivity or soreness, including slight discomfort when chewing, is a normal part of the healing process and typically resolves within a few days to two weeks. If the pain upon biting is sharp, immediate, and feels like the tooth is hitting first, contact your dental office for a bite adjustment. This quick, non-invasive procedure provides rapid relief by shaving down the excess filling material.
Certain symptoms signal a potentially serious complication requiring urgent evaluation. Seek immediate attention if the pain is severe, throbbing, or wakes you up from sleep without external stimulus. Pain that is constant, accompanied by swelling in the gums or face, or persists beyond two weeks should be checked by a professional. These signs may indicate irreversible pulpitis, an abscess, or a deep structural issue requiring intensive treatment to save the tooth.