A dental crown is a cap designed to cover a tooth that has been damaged or weakened. This restoration completely encases the visible portion of the tooth, restoring its original shape, size, and strength. Crowns are utilized after procedures like root canals or when a tooth has a large filling or fracture. They provide a protective covering that allows the tooth to function normally. Recognizing the signs that this protective layer has failed is important for preventing further damage to the underlying tooth structure. This guide outlines the indicators that suggest a crown has cracked or sustained damage.
Visual Indicators of Crown Damage
Crown failure often appears as a visible disruption on the surface. Small, linear defects known as hairline fractures are the most subtle form of damage, sometimes appearing only as thin lines difficult to spot without magnification. These cracks represent a structural weakness that can worsen over time, even if they do not immediately cause pain. Larger damage includes chips or missing pieces, which typically occur along the biting edge or the margin where the crown meets the gumline. When a crack extends down to the margin, it compromises the seal protecting the natural tooth underneath, and discoloration or a dark line near the gum tissue can signal decay beneath the cap.
Sensory Symptoms of a Cracked Crown
A crack that is not visible often triggers physical sensations. One common indicator is a sharp, brief pain experienced when biting down or chewing food, which may also present as fleeting pain when the biting pressure is released. This discomfort, often associated with “cracked tooth syndrome,” occurs because the movement of fractured segments stimulates the nerve within the tooth structure. Another symptom is heightened sensitivity to temperature changes, particularly with hot or cold foods and beverages. This occurs because the crack creates a pathway for external stimuli to reach the dentin or pulp. Patients may also notice a rough or jagged edge with their tongue, or feel that the crown is slightly loose, suggesting the cement seal has been compromised.
Common Causes of Crown Failure
Crowns are subject to breakdown under excessive or repeated strain. A common source of damage is trauma, including accidents, sports injuries, or any direct impact to the mouth, which can create immediate, significant fractures. Habits like chronic teeth grinding or clenching place intense, repeated pressure on the crown structure. This continuous stress leads to the formation of stress fractures and material fatigue over time. Chewing on extremely hard objects, such as ice or hard candies, can exceed the material’s fracture strength. Even without trauma, natural wear and tear from daily chewing eventually leads to material fatigue, often necessitating replacement after 10 to 15 years.
Immediate Action and Professional Treatment
Upon noticing any signs of a cracked crown, contact a dental professional immediately for an evaluation. Until the appointment, avoid applying pressure to the affected side of the mouth to prevent further propagation of the fracture. If the crown has a sharp edge that is irritating the cheek or tongue, covering the area with dental wax can provide relief.
Repair Options
Professional treatment depends on the crack’s severity and location. Minor chips or small, non-structural cracks may be repaired using dental bonding, where a tooth-colored resin material is applied and hardened to restore the contour. This repair option is typically quicker and more cost-effective than a full replacement. If the crown is loose but intact, the dentist may clean the area and recement it back onto the prepared tooth.
When Replacement is Necessary
Replacement becomes necessary when the crack is large, compromises the structural integrity of the crown, or if decay has penetrated the underlying natural tooth. In this situation, the damaged crown is removed, and the tooth is prepared again to accommodate a new restoration. The process involves taking new impressions and placing a temporary crown while the permanent one is being created in a dental laboratory. The new crown will then be cemented in a subsequent visit, restoring the tooth’s protection and function.