A dental crown falling off to reveal a black tooth underneath can be unsettling. This common dental issue signals the need for prompt professional attention. Understanding the reasons and appropriate steps can help manage the situation.
Immediate Steps to Take
If your crown detaches, retrieve it and store it safely. Gently clean both the dislodged crown and the exposed tooth using warm water. Avoid harsh chemicals, as they could damage the tooth or crown. Avoid chewing on the affected side to prevent injury or accidental swallowing.
Contact your dentist as soon as possible for an emergency appointment. The exposed tooth is vulnerable to sensitivity, decay, and potential infection. While waiting, temporary measures like over-the-counter dental cement or toothpaste can re-seat the crown, but these are not permanent solutions and should not delay professional evaluation.
Understanding the Black Discoloration
Black discoloration underneath a fallen crown can stem from several causes. Most commonly, it points to dental decay (a cavity). Bacteria can infiltrate the tooth structure beneath a crown, especially if the crown’s seal is compromised, leading to decay that often appears dark or black. If decay is the cause, the tooth structure may feel soft or mushy when touched.
Another reason for a tooth to appear black is a previous root canal procedure. Teeth that have had a root canal can naturally darken over time due to internal changes. This discoloration, while visually alarming, does not always indicate a new problem. Old amalgam (silver) fillings can leach metallic ions into the tooth structure, causing gray or black staining visible once the crown is removed. In some instances, the dark metal substructure of a porcelain-fused-to-metal crown might also be visible if the porcelain layer has chipped or the crown is translucent, creating a shadowed appearance.
Why Crowns Become Loose
Several factors can cause a dental crown to become loose and fall off. Dental cement used to bond the crown to the tooth can degrade over time due to constant chewing forces and exposure to oral fluids, weakening the adhesive bond and leading to detachment. Insufficient tooth structure after preparation can also hinder the crown’s retention, as there may not be enough surface area for cement adhesion.
Trauma, such as biting something exceptionally hard or a direct impact, can dislodge a crown. Persistent habits like teeth grinding or clenching (bruxism) exert excessive pressure on crowns, potentially weakening their bond over time. A crown not initially fitted precisely can also become loose; minor gaps or inaccuracies during the impression process can compromise the seal, allowing detachment. Decay forming underneath the crown can also weaken the tooth structure, leading to its eventual failure.
Dental Diagnosis and Treatment
A comprehensive examination will determine the exact cause of the crown’s detachment and black discoloration. This involves visual inspection, probing for softness or sensitivity, and dental X-rays. X-rays assess the underlying tooth structure, identify hidden decay, and evaluate the health of the surrounding bone.
Treatment options vary widely depending on the diagnosis. If the crown is intact, the underlying tooth healthy, and no significant decay present, the dentist may clean and re-cement the existing crown. If minor decay is present, it can be removed and filled, and a new crown placed if the old one no longer fits. When decay is extensive and has reached the tooth’s pulp, a root canal may be necessary to remove infected tissue, followed by a new crown. In severe cases where the tooth is extensively damaged and beyond repair, extraction might be the only option, with subsequent discussion of replacement solutions like implants or bridges.
Preventing Future Dental Issues
Maintaining oral hygiene is important for preventing future dental problems, including issues with crowns. Regular brushing at least twice a day and daily flossing remove plaque and food debris, particularly around the crown and gum line. This practice helps prevent new decay from forming around the edges of the crown, a common site for bacterial infiltration.
Routine dental check-ups and professional cleanings are important. These visits allow the dentist to monitor crown integrity, detect early signs of decay or wear, and address potential issues before they escalate. Avoiding chewing very hard or sticky foods can help protect crowns from dislodgement or damage. For individuals who grind or clench their teeth, a custom-fitted nightguard can protect crowns and natural teeth from excessive forces.