Pain in a tooth with a crown, especially when biting or chewing, is a common issue. This discomfort signals stress or a problem with the underlying tooth structure, the crown, or the surrounding tissues. While a dental crown strengthens and protects a compromised tooth, it does not prevent all complications. The localized pain felt when biting down points toward mechanical or biological issues requiring professional dental evaluation.
Crown-Related Mechanical Causes
The most common mechanical cause of immediate pain upon biting is occlusal interference, often described as a “high spot” on the crown. If the crown is slightly taller than the surrounding teeth, it contacts the opposing arch prematurely and absorbs excessive force during chewing. This concentrated, uneven pressure strains the periodontal ligament, the fibers that anchor the tooth root to the jawbone. The ligament becomes inflamed, leading to localized pain when you bite down.
The integrity of the crown’s seal, or margin, can also contribute to pressure sensitivity. A loose crown or one with a compromised fit allows saliva, bacteria, and food debris to seep underneath. This leakage irritates the underlying prepared tooth structure, leading to sensitivity exacerbated when the crown shifts slightly under biting pressure. The movement causes discomfort and leaves the remaining tooth vulnerable to decay.
It is also possible that the crown material itself has fractured or cracked due to trauma or excessive biting forces. While crowns are durable, a hairline fracture in the ceramic or metal can introduce a pathway for sensitivity. When the opposing tooth makes contact, the force spreads the crack, causing a sharp, momentary pain. A fractured crown requires repair or replacement to restore the tooth’s protective barrier and eliminate the source of pain.
Internal Tooth and Root Issues
Pain under pressure can originate from the interior of the tooth, particularly the dental pulp, which contains the nerves and blood vessels. This internal inflammation, known as pulpitis, can occur if deep decay develops at the margin or if the tooth preparation was traumatic to the nerve. When the pulp is inflamed, biting down compresses the sensitive tissue, resulting in a throbbing or aching pain. This condition often progresses to an irreversible state, frequently requiring root canal therapy to remove the infected nerve tissue.
A more complex cause is Cracked Tooth Syndrome, where the underlying tooth structure or root has a fracture. These cracks are often vertical and can extend from the chewing surface down toward the root. The crown may hold the tooth together, but the fracture acts like a hinge, causing the tooth segments to flex slightly when pressure is applied. When the bite is released, the momentary separation and snap-back of the fractured pieces results in a characteristic sharp, quick pain.
If the crowned tooth previously underwent a root canal procedure, pain upon biting may indicate a failed treatment or a new infection at the root tip. This re-infection, often forming an abscess, creates a pocket of pus and inflammation within the jawbone around the root end. The pressure exerted when biting pushes the tooth slightly into this inflamed area, causing significant pain. The infection may be due to residual bacteria, an incomplete seal in the root canal filling, or a newly developed crack in the root.
Diagnosis and Treatment Pathways
A dental examination for pressure pain typically begins with a visual inspection and a review of the patient’s symptoms. The dentist uses specialized diagnostic tools to pinpoint the exact source of discomfort. Standard periapical and bitewing X-rays are taken to visualize the tooth root, surrounding bone, and the area under the crown, looking for signs of decay, bone loss, or infection at the root tip.
A targeted biting test is used to isolate the painful area, often employing a device like a cotton roll or a specialized plastic instrument. The patient bites down on the tool, which helps confirm if the pain relates to occlusal interference or a crack in a specific cusp. Pulp testing, using thermal or electric stimuli, determines the vitality of the remaining tooth nerve, helping to diagnose pulpitis.
Treatment is directly determined by the diagnostic findings. If the crown is “too high,” the dentist performs an occlusal adjustment, using specialized burs and articulating paper to precisely reshape the biting surface until the bite is balanced. If pulpitis or an abscess is confirmed, root canal therapy is the standard procedure to remove the diseased tissue and save the tooth. If a vertical root fracture is identified, especially one that extends below the gum line, the tooth is often considered non-restorable and requires extraction.