A dental crown is a prosthetic cap cemented over a damaged tooth to restore its shape and strength. While the crown material is impervious to decay, the natural tooth structure beneath it remains vulnerable. Pain in a crowned tooth signals that the protective seal has been compromised, requiring prompt dental attention to prevent serious complications.
Why Does a Crowned Tooth Hurt
Pain under a crown often originates from recurrent decay developing at the margin, the line where the crown meets the natural tooth. If this seal is breached, bacteria infiltrate the gap, leading to a new cavity underneath the crown. This hidden decay progresses rapidly because it is difficult to detect early and is shielded from regular cleaning.
A micro-fracture in the underlying tooth is another source of pain, frequently caused by excessive biting forces or teeth grinding (bruxism). Even a hairline crack transmits pressure directly to the pulp, resulting in sharp pain when biting down or releasing pressure. An ill-fitting or loose crown also allows oral bacteria and temperature changes to reach the sensitive prepared tooth, causing discomfort.
The pain may also indicate pulpitis, meaning the dental nerve is inflamed or infected. This occurs if decay reaches the pulp chamber or if the tooth suffered trauma during the initial crown preparation. Signs of nerve involvement include lingering sensitivity to hot or cold temperatures or a constant, throbbing ache. Gum recession can also expose the tooth root surface near the crown margin, leading to heightened sensitivity.
Immediate Steps for Temporary Relief
While waiting for a dental appointment, over-the-counter pain relievers can manage the discomfort temporarily. Non-steroidal anti-inflammatory drugs (NSAIDs) like ibuprofen are effective, as they reduce inflammation often associated with a toothache. Follow the recommended dosage and consult a pharmacist if you are taking other medications.
Rinsing the mouth with a warm saltwater solution several times a day can soothe inflamed tissues. Dissolve about half a teaspoon of salt in eight ounces of warm water and swish gently around the affected area. Avoid chewing on the painful side and avoid foods or drinks that are extremely hot, cold, or sugary, as these can trigger sharp sensitivity responses.
If the crown feels loose or has fallen off completely, you must retrieve it and keep it safe. You can purchase a temporary dental cement kit from most pharmacies to temporarily re-adhere the crown to the underlying tooth. First, gently clean the inside of the crown and the prepared tooth structure, then apply a small amount of the temporary cement to the inside of the crown before seating it back onto the tooth. This temporary fix protects the sensitive underlying tooth from further trauma and infection until you can see the dentist.
Professional Treatment Pathways
Upon examination, the dentist uses dental X-rays and tactile probes to determine the precise cause and extent of the problem. If the pain is due to minor decay localized at the crown’s margin, the dentist may remove the decay and place a small filling directly at the junction. This is only feasible for shallow decay that has not undermined the crown’s structural integrity.
More extensive decay usually requires the crown to be removed entirely, allowing full access to clean out the affected tooth structure. Once the decay is removed, a new, custom-fitted crown is fabricated and cemented onto the repaired tooth. If the decay is deep enough to reach the inner pulp, or if the nerve is irreversibly inflamed, root canal therapy is necessary to save the tooth.
If root canal therapy is needed, the dentist or an endodontist may perform the procedure by drilling a small access hole directly through the top surface of the existing crown. This approach is preferred if the crown is new and well-fitting, as it preserves the restoration and avoids replacement costs. The access hole is sealed with filling material after the infected pulp is removed and the root canals are cleaned. If the crown is old, has poor margins, or is difficult to drill through, it will be removed before the root canal, necessitating a new crown afterward.
The most severe cases, such as a deep vertical root fracture or decay that has destroyed too much tooth structure below the gumline, may lead to extraction. If extraction is necessary, the dentist will discuss replacement options, primarily an implant or a bridge. A dental implant replaces the tooth root, maintaining jawbone health. A bridge uses the adjacent teeth as anchors, requiring them to be reshaped to support the replacement tooth.