A dental crown is a custom-made cap designed to cover a damaged tooth, restoring its shape, strength, and appearance. Crowns are durable restorations, often made from porcelain, ceramic, or metal alloys, but they are not immune to failure. Common reasons a crown might fail include the natural breakdown of the cement bond over time, trauma from biting hard objects, or the development of new decay beneath the crown structure. Experiencing a loose or detached crown can be alarming, but immediate, temporary steps can protect the underlying tooth until professional dental care is secured.
Handling a Crown That Has Come Off
The first step after a crown detaches is to carefully locate and clean the restoration. Gently rinse the crown with warm water and inspect the exposed tooth structure for any sharp edges or damage. The underlying tooth, often called the prepared tooth, will be sensitive to temperature changes and vulnerable to further damage.
To temporarily stabilize the crown, purchase over-the-counter temporary dental cement from a local pharmacy. Apply a small amount of adhesive inside the crown and attempt to seat it gently back onto the tooth, ensuring it faces the correct direction.
Alternatively, a dab of petroleum jelly or toothpaste can offer minimal, short-term retention if no dental cement is available. Avoid using household glues, such as superglue, as they are toxic and can damage the crown and the underlying tooth, complicating the permanent repair.
Once the crown is temporarily secured, avoid chewing on that side of your mouth and consume only soft foods to prevent dislodging it again. These temporary measures reduce sensitivity and protect the tooth, but they are not a substitute for professional re-cementing. Contacting a dental office promptly is necessary to prevent complications like further tooth decay or the shifting of adjacent teeth.
When a Dentist Must Intervene
A loose or detached crown requires a professional assessment to determine the root cause of the failure. The dentist will take X-rays to evaluate the health of the prepared tooth structure and check for any decay that may have formed beneath the crown margin. They will also inspect the crown itself for cracks or signs of wear that might compromise its structural integrity.
If the crown is undamaged, the underlying tooth is healthy, and the cause was simply cement wash-out, the dentist can often re-cement the existing crown. This procedure involves thoroughly cleaning the crown and the tooth to remove all traces of old cement and debris. Re-cementing is a straightforward and cost-effective solution when the tooth and crown remain viable.
If significant underlying tooth decay is present, if the crown structure is compromised, or if the original crown fit was poor, a full replacement becomes necessary. Decay must be removed and the tooth rebuilt before a new crown can be placed, requiring new impressions to fabricate a custom-fitted restoration. Repeated failure often indicates the prepared tooth structure lacks sufficient material to retain the cap, suggesting a need for a new crown design or a post and core buildup.
Repairing Chipped or Cracked Crowns
Crowns can sustain damage while still firmly attached to the tooth, often manifesting as chips or cracks in the surface material. These structural failures commonly occur from biting down on excessively hard foods or from the repetitive stress caused by bruxism, which is chronic teeth grinding. Even minor chips should be addressed quickly because the exposed, rough edges can irritate the tongue and cheek tissue.
For minor chips, particularly in porcelain or ceramic crowns, the dentist can often repair the area using dental bonding. This involves applying a tooth-colored composite resin directly to the chipped surface, molding it to the correct contour, and hardening it with a specialized light. This repair is generally quicker and less invasive than a full replacement, though the bonded area may not be as durable as the original crown material.
When the crown exhibits a major fracture, a deep crack, or significant material loss, a simple bonding repair may not be sufficient to restore its function and strength. In these situations, full crown replacement is recommended to prevent further structural failure and protect the underlying tooth from potential bacterial leakage. Replacement ensures the new restoration has proper margins and a strong, uniform structure to withstand the forces of chewing.
Long-Term Care and Prevention
Maintaining the integrity of a dental crown long-term primarily involves meticulous oral hygiene focused on the area where the crown meets the gumline. This margin is susceptible to plaque buildup, which can lead to decay in the underlying natural tooth structure and eventual cement failure. Brushing twice daily and flossing around the crown are both necessary to protect the restoration.
When flossing around a crown, slide the floss gently down to the gumline in a C-shape against the side of the tooth. Instead of snapping the floss back up, which risks pulling the crown loose, pull the floss out sideways from between the teeth. Water flossers are an excellent alternative, using a pressurized stream of water to clean the margins without mechanical risk.
Reducing mechanical stress on the crown is a preventative measure. Patients with bruxism (teeth grinding) should wear a custom-fitted night guard to distribute biting forces evenly and protect the crown from premature wear or fracture. Avoiding extremely hard or sticky foods, such as hard candies and caramels, prevents physical trauma that can chip the material or weaken the cement bond. Regular dental check-ups allow the dentist to monitor the crown’s margins and fit using X-rays, identifying small issues before they escalate into failure.