An extracoronal dental restoration fits over the outside of a tooth, covering part or all of its outer surface. Unlike a traditional filling that sits inside a tooth, this approach is used for significant damage from decay or trauma. It acts like a protective helmet, providing an external layer of strength. These restorations are designed to restore the tooth’s original shape, function, and appearance.
Common Extracoronal Restorations
Full crowns are a frequent type of extracoronal restoration, acting as a cap that covers the entire visible portion of a tooth above the gumline. Dentists use them when a tooth has been weakened by extensive decay, a large filling, or a fracture. Teeth that have undergone root canal therapy often receive a crown because the procedure can make them more brittle. The crown encases the compromised tooth, providing structural support.
A more conservative option is a dental onlay, sometimes called a partial crown. An onlay is used when the damage is more moderate and doesn’t involve the whole tooth. It is designed to cover one or more of the cusps, which are the raised points on the biting surface of a molar or premolar. By preserving more of the natural tooth structure, onlays leave healthy enamel intact.
Veneers are another form of extracoronal restoration, but their purpose is primarily cosmetic. These are thin shells, typically fabricated from porcelain, that are bonded to the front surface of teeth. Veneers are used to correct aesthetic issues such as discoloration, chips, gaps, or minor misalignment. Unlike crowns and onlays, veneers focus on improving the appearance of the front teeth.
The Restoration Process
Receiving an extracoronal restoration typically involves two appointments. During the first visit, the dentist prepares the tooth after administering a local anesthetic. The dentist will reshape the tooth by removing decayed tissue and a small amount of enamel. This reshaping creates space for the restoration to fit properly. An impression is then taken using a physical putty-like material or a digital scanner and sent to a dental lab. Before the patient leaves, a temporary restoration is placed over the prepared tooth.
The second appointment occurs after the permanent restoration has been made. The dentist begins by removing the temporary cover and cleaning the tooth. The new restoration is then placed on the tooth to check for a proper fit, correct bite, and satisfactory color match. After any necessary adjustments are made, the restoration is permanently bonded to the tooth using a strong dental cement.
Longevity and Care of Restorations
The lifespan of an extracoronal restoration generally lasts between 5 and 15 years, though some can last much longer. Several factors influence this longevity, including the type of material used, the patient’s oral hygiene, and personal habits. For instance, clenching or grinding teeth can place excess stress on the restoration, potentially shortening its lifespan.
Proper maintenance is necessary for the long-term success of the restoration. The tooth underneath is still vulnerable to decay, particularly at the margin where the restoration meets the tooth. Therefore, diligent oral hygiene, including regular brushing and flossing, is important. It is also advisable to avoid chewing on extremely hard items, such as ice or hard candies, which could fracture the restoration. Routine dental check-ups allow a dentist to monitor the restoration and the health of the surrounding gums and tooth.