A dental crown, often called a cap, is a tooth-shaped covering placed over a damaged tooth to restore its shape, size, strength, and appearance. Crowns are typically used when a tooth has extensive decay, is fractured, or has undergone a root canal, providing protection and improving chewing. While crowns protect the visible tooth, the underlying structure remains susceptible to decay. Thus, a cavity can form underneath a dental crown.
How Cavities Develop Under Crowns
Cavities develop under dental crowns primarily due to compromised integrity at the crown’s margin, where it meets the natural tooth structure. This area, often near the gum line, is particularly vulnerable to bacterial accumulation. Over time, the dental cement securing the crown can degrade, creating microscopic gaps or “microleakage” that allow bacteria and food particles to seep underneath, initiating decay.
Gum recession also exposes the tooth root beneath the crown, which is softer and more susceptible to decay than enamel. Inadequate oral hygiene, such as insufficient brushing and flossing around the crown, allows plaque to build up, especially at the gum line, fostering decay. Furthermore, a poorly fitted crown can create spaces where bacteria infiltrate and lead to decay. Even teeth that have undergone root canal therapy can develop decay if residual bacteria are left behind or if the crown’s seal is compromised.
Recognizing the Signs of a Hidden Cavity
Identifying a cavity beneath a crown can be challenging because the crown obscures the decay, often delaying detection until the issue is advanced. However, several indicators might signal a hidden problem. Sensitivity to hot, cold, or sweet foods and drinks, especially if new or worsening around the crowned tooth, can be a symptom. Persistent or throbbing pain, particularly when biting down or chewing, is another common sign.
Swelling, redness, or tenderness in the gum tissue surrounding the crowned tooth may indicate an underlying infection or decay. A persistent bad taste in the mouth or an unusual odor from the crowned area can also suggest the presence of bacteria and decay. Sometimes a dark spot or discoloration might be visible at the crown margin, or the crown might feel loose, indicating decay has weakened the underlying tooth. Any of these signs should prompt an immediate dental evaluation.
Addressing a Cavity Under a Crown
Once a cavity under a crown is suspected, a dentist will conduct a thorough examination, often utilizing X-rays to visualize the extent and location of the decay. The treatment approach depends on the severity and accessibility of the decay. For minor decay along the crown’s margin, it might sometimes be addressed with a dental filling after removing the crown.
In many cases, particularly with moderate decay, the existing crown will need to be removed to treat the decay effectively. After the decay is cleaned and removed, a new filling or buildup is placed, and a new crown is then fitted. If the decay is extensive and has reached the tooth’s inner pulp, root canal therapy becomes necessary before a new crown can be placed. If the tooth structure is too compromised to be saved, extraction might be the only option, followed by discussions about tooth replacement solutions such as a dental implant or bridge.
Protecting Your Crowned Tooth
Protecting a crowned tooth from future decay involves consistent oral care practices. Maintaining excellent oral hygiene includes brushing at least twice daily with fluoride toothpaste and flossing every day, paying special attention to the area around the crown and the gum line. Using an antibacterial mouthwash can further help reduce plaque and bacteria around the crown.
Regular dental check-ups and professional cleanings are also important, as dentists can detect issues like compromised crown seals or early signs of decay. Limiting the intake of sugary and acidic foods and drinks is advisable, as these contribute to bacterial growth and enamel erosion. For individuals who grind or clench their teeth (bruxism), wearing a custom-fitted nightguard can protect crowns from excessive pressure and potential damage to the seal. Promptly addressing any changes or discomfort with a crowned tooth can prevent minor issues from escalating into more complex problems.