A dental crown is a cap placed over a damaged or weakened tooth to restore its shape, size, strength, and appearance. While durable, crowns occasionally detach, causing immediate alarm. When a crown falls off, the underlying tooth structure is exposed to the harsh environment of the mouth, requiring prompt attention to protect the vulnerable tooth underneath.
The Immediate Question: Assessing Pain and Sensitivity
The experience of pain when a dental crown falls off varies widely, depending on the condition of the tooth beneath the restoration. If the tooth has had a root canal, the nerve tissue is no longer present, and the patient may feel little to no pain, only an unusual sensation. If the tooth underneath is still “vital” or alive, the exposure can lead to sharp discomfort.
The primary source of immediate pain or sensitivity is the exposure of the dentin, the layer directly beneath the enamel. Dentin contains thousands of microscopic tubules connecting to the pulp and the nerve. Without the crown’s insulating layer, cold air, hot liquids, or sweet foods travel directly through these tubules, causing a sudden, intense jolt of pain.
Emergency Care: What to Do Right Now
First, locate the crown and carefully remove it from your mouth to prevent accidentally swallowing or inhaling it. Rinse the crown with warm water to clean off debris, and store it in a safe container to bring to your appointment. Immediately contact your dentist to explain the situation and schedule an appointment, ideally for the same day.
While waiting for your appointment, protect the exposed tooth structure. The inner tooth is vulnerable to bacteria and further damage, so avoid chewing on the side of your mouth where the crown is missing. If the exposed tooth surface feels sharp or jagged, cover the area with dental wax, available at most pharmacies.
To temporarily re-seat the crown, if it is intact and fits back on easily, use over-the-counter temporary dental cement, denture adhesive, or even toothpaste as a short-term measure. Apply the temporary agent only to the inside of the crown, place it back onto the tooth, and bite down gently to secure it. Never use household adhesives like superglue, as these are toxic and make professional reattachment impossible.
Why Dental Crowns Fail
Crowns are not permanent and typically last between 5 and 15 years, but several factors can cause premature failure. The most common reason is the breakdown of the dental cement holding the crown onto the tooth preparation. Over time, the cement may dissolve slightly, creating a micro-gap that allows the crown to loosen and detach.
Decay, also known as secondary caries, forming beneath the crown is another frequent cause of failure. Although the crown itself cannot decay, the margin where the crown meets the natural tooth is susceptible to bacterial plaque buildup. If decay progresses, it compromises the structural integrity of the underlying tooth, weakening the foundation and causing the crown to lose its fit.
Excessive forces, such as chronic teeth grinding (bruxism) or biting down on hard or sticky foods, can also lead to dislodgement. These actions place immense stress on the crown material and the cement bond, potentially causing the crown to fracture or snap the adhesive bond. Furthermore, an improper fit or insufficient preparation of the tooth structure can contribute to a loose crown, accelerating failure.
Next Steps: Professional Repair and Replacement
When you see your dentist, the first step is a thorough assessment, often including a visual examination and digital X-rays. The dentist evaluates the condition of the crown, the underlying tooth, and the surrounding gum tissue to determine the cause of the failure. This evaluation checks for signs of new decay, fracture, or damage to the crown itself.
If the crown is undamaged, the fit remains acceptable, and the underlying tooth is healthy, the dentist can clean the crown and the tooth, then re-cement the existing crown using a strong, permanent adhesive. This process is typically fast and pain-free, restoring the function of the tooth immediately. However, if the crown is fractured or if significant decay is found, a complete replacement is necessary.
For a replacement, the dentist removes any decay, potentially reshapes the tooth, and takes a new digital scan or impression to create a custom-fitted permanent crown. A temporary crown is placed until the final restoration is ready, which usually takes a few weeks. To extend the life of your new crown, preventative maintenance is advised, including avoiding chewing on hard objects and wearing a custom nightguard if you grind your teeth.