A dental crown is a tooth-shaped cap placed over a damaged tooth to restore its size, shape, strength, and appearance. It is cemented onto the existing tooth structure, encasing the entire visible portion above the gum line. Although crowns are designed to be a long-term solution, they occasionally become loose and fall off. A temporary re-cementation is possible for immediate relief, but it must be done with specific materials and is not a permanent fix.
Immediate Actions After a Crown Falls Off
Your first step upon noticing a dislodged crown should be to safely retrieve it, as the dentist may be able to reattach the original cap. Clean the crown gently with water to remove any debris or old cement, then store it in a small, secure container to protect it from damage. Inspect the crown for any cracks or chips, and check the interior for large pieces of old cement that may need professional removal before re-cementation.
The exposed underlying tooth may feel sensitive to temperature changes or pressure since its protective enamel layer is gone. Gently rinse your mouth with warm salt water to clean the area and soothe irritated gum tissue. Avoid chewing on the side of your mouth where the crown is missing to prevent further damage to the exposed tooth structure.
Examine the prepared tooth carefully for damage, such as a sharp edge or new decay. Decay is one of the most common reasons a crown fails, as it erodes the underlying structure needed to hold the crown securely. If the tooth has a post or significant buildup, ensure that structure is still intact and was not dislodged along with the crown.
Safe Temporary Re-cementation Options
Temporary re-cementation is possible for a short-term fix until a dental appointment. Use materials specifically designed for temporary dental use. Over-the-counter dental cement kits are the best option and are widely available in pharmacies and drugstores.
These kits contain a zinc-oxide based material that is biocompatible and easily removable by a dentist. To apply the cement, ensure both the inside of the crown and the prepared tooth surface are clean and dry. Apply a small amount of the temporary cement evenly around the inner circumference of the crown, avoiding overfilling the cap.
Carefully seat the crown back onto the tooth, ensuring it is oriented correctly and fully seated. Check the fit by gently closing your mouth to ensure your bite feels normal. Hold the crown in place with light pressure while the cement begins to set, then gently remove any excess material. If a dental cement kit is unavailable, toothpaste or petroleum jelly can be used as a last resort to protect the tooth, though they offer minimal retention.
Never use household adhesives, such as superglue (cyanoacrylate), to reattach a dental crown. These glues are toxic, are not designed for oral use, and can cause irritation or chemical burns to the gums and pulp tissue. The permanent bond they form is extremely difficult for a dentist to remove without potentially damaging the tooth or the crown, leading to a more extensive repair.
Professional Assessment and Permanent Repair
Using a temporary cement is only a stopgap measure; a visit to the dentist is mandatory for a permanent fix. The temporary bond is intentionally weak, allowing the dentist to easily remove the crown for proper cleaning and inspection. Leaving a crown off or relying on a temporary fix for too long can allow adjacent teeth to shift, preventing the crown from fitting properly later.
During the appointment, the dentist will assess the underlying cause of the crown failure, often starting with a dental radiograph to check for recurrent decay. If the tooth structure is sound and the crown is undamaged, the dentist will clean both surfaces thoroughly, removing all traces of old cement and debris. They will then use a specialized, medical-grade permanent dental cement, which forms a long-lasting, moisture-resistant seal.
If decay is present, the dentist must first remove the decayed material and restore the tooth structure, potentially requiring a new core buildup before re-cementation. If the crown is cracked, significantly chipped, or does not fit correctly due to tooth movement, a new crown may be necessary. The final step involves checking the bite and making minor adjustments to ensure the crown functions correctly and does not place undue stress on the tooth.