A dental crown is a custom-made, tooth-shaped cap placed over a damaged or decayed tooth to restore its size, shape, function, and appearance. They protect the compromised tooth structure underneath from further harm. While crowns are crafted for durability, they may occasionally fail due to becoming loose, fracturing, or chipping, which exposes the underlying tooth and requires prompt professional attention.
Immediate Steps After Crown Damage
The first priority upon discovering a damaged or dislodged crown is to manage the situation until a dental appointment can be secured. If the crown has come off completely, retrieve it, clean it gently with water, and store it safely, as an intact crown may be re-cemented by your dentist. Avoid scrubbing the crown or using toothpaste, and keep all broken fragments, which help the dentist assess the damage.
If the exposed natural tooth is causing sensitivity, warm salt water rinses can help cleanse the area and offer some temporary relief. Over-the-counter pain relievers, following the recommended dosage, can be used to manage any sharp or lingering pain. If sharp edges remain on the tooth or the remaining crown, cover them temporarily with dental wax or a piece of sugar-free chewing gum to protect the soft tissues of your mouth from cuts.
If the crown is intact but dislodged, temporary dental cement or a small amount of toothpaste may be used to secure it back in place. When re-seating the crown, ensure it is aligned correctly, and never force it onto the tooth. Avoid chewing on the affected side entirely to prevent swallowing the crown or further damaging the exposed tooth.
Professional Dental Assessment
The professional assessment begins with a thorough visual inspection to determine the immediate nature of the failure, such as whether the crown is loose, chipped, or completely fractured. The dentist uses a small instrument to gently probe the margins around the tooth and crown, checking for gaps that could indicate leakage or improper fit. This step identifies where the restoration meets the natural tooth structure, a common area for problems.
A standard part of the diagnostic process involves taking dental X-rays of the affected area. These images evaluate the condition of the underlying tooth structure, including the root and bone, which is not visible during a standard oral examination. The X-ray helps determine if there is new decay beneath the crown, if the tooth has fractured at the root level, or if a previous root canal treatment has failed, all of which impact the final treatment decision.
The assessment must distinguish between three main scenarios: mechanical failure (crown debonding), crown material failure (fracture), or biological failure involving the underlying tooth structure. For instance, a loose but undamaged crown may indicate cement failure, while a fractured crown suggests excessive force or material fatigue. An accurate diagnosis is necessary because a repair will only be successful if the root cause of the failure is identified and addressed.
Treatment Options for Repair or Replacement
The treatment selected for a broken crown depends entirely on the findings of the dental assessment. If the crown is fully intact and the underlying tooth is healthy with no new decay, the simplest fix is often re-cementation. The dentist cleans both the inside of the crown and the prepared tooth structure before bonding the crown back into place using specialized dental cement. This fast procedure restores function quickly if the fit remains secure.
For crowns with minor aesthetic or structural damage, such as small chips or hairline cracks, a full replacement may not be necessary. The dentist may use composite bonding, applying a tooth-colored resin material to fill the chipped area and hardening it with a specialized light. Alternatively, tiny imperfections can be smoothed out and polished to eliminate rough spots without compromising the crown’s integrity.
A full crown replacement becomes necessary when the existing crown is severely fractured, ill-fitting, or if the diagnosis reveals significant decay or structural damage to the tooth underneath. The old crown is carefully removed, and the underlying tooth is re-prepared to create a clean foundation for the new restoration. Impressions of the prepared tooth are taken and sent to a dental laboratory, where the new, permanent crown is fabricated to ensure a precise fit and natural appearance.
While the new crown is being manufactured, the dentist places a temporary crown to protect the sensitive tooth, maintain alignment, and allow the patient to chew. If the tooth underneath has extensive decay that reached the pulp, or if a previous root canal failed, root canal therapy must be completed before the new crown is seated. In severe cases where the remaining tooth structure is too compromised to support restoration, the tooth may require extraction, with a dental implant or bridge considered as a replacement option.
Understanding Why Crowns Fail
Crowns are robust restorations, but they are not impervious to the forces and conditions within the mouth. One common reason for failure is the development of secondary decay in the natural tooth structure immediately beneath the crown’s edge. Since the tooth is vulnerable to bacteria at the margins, poor oral hygiene or gum recession can lead to decay that compromises the tooth’s ability to hold the crown securely.
Mechanical stress is another frequent cause of damage, often resulting from habits like bruxism (unconscious grinding or clenching of teeth). This excessive force can lead to fractures in the crown material or weaken the cement bond, causing the crown to loosen or crack. Similarly, biting down on extremely hard objects, such as ice, hard candies, or using teeth to open packages, can cause sudden, traumatic fractures.
The integrity of the cementation itself can also be a factor in failure, as the adhesive material securing the crown can degrade or wash out over time, causing the crown to become loose. If the crown was not initially fabricated or seated with a precise fit, the resulting marginal gap can allow oral fluids and bacteria to seep in, accelerating the failure process.