When a tooth is damaged by decay or injury, various restorative options are available. Dental onlays offer a specific approach, restoring teeth with damage that falls between a traditional filling and a full crown.
Understanding Dental Onlays
A dental onlay is a custom-made restoration that dentists use to repair teeth with moderate to extensive damage. Unlike a conventional filling, which is placed directly into a cavity, an onlay is fabricated outside the mouth, typically in a dental laboratory, and then bonded onto the tooth. Onlays are often composed of durable materials such as porcelain, composite resin, or gold, chosen for their strength and aesthetic properties.
An onlay’s distinct feature is its coverage: it addresses damage including one or more cusps—the raised points on the chewing surface of a tooth. This differs from an inlay, which fits within the grooves between cusps, and a full dental crown, which completely covers the entire visible portion of the tooth. For this reason, an onlay is sometimes referred to as a “partial crown.”
When Onlays Are the Right Choice
Dentists often recommend onlays when a tooth has damage too extensive for a simple filling but not severe enough to require a full crown. This intermediate level of damage might stem from significant decay, a large fracture, or a compromised existing filling. Onlays are particularly suitable for preserving more of the natural tooth structure compared to crowns, as they only replace the damaged portion.
Onlays are an option when a tooth’s structure is weakened, such as by a large cavity, and might be prone to cracking if restored with a standard filling. By covering the affected cusps, onlays provide support and protect weakened areas from further degradation under chewing forces.
The Onlay Placement Process
Receiving a dental onlay typically involves two appointments. During the first visit, the dentist prepares the tooth by removing any decay or compromised tooth structure, similar to preparing for a filling. An impression of the prepared tooth is then taken; this mold serves as a precise guide for a dental laboratory to custom-fabricate the permanent onlay. To protect the tooth between appointments, a temporary onlay is placed.
The second appointment occurs once the custom onlay has been fabricated and delivered from the lab. The temporary restoration is carefully removed, and the tooth is thoroughly cleaned. The dentist then fits the permanent onlay, ensuring it aligns correctly with the bite and surrounding teeth. Once satisfied with the fit, the onlay is permanently bonded to the tooth using a strong dental adhesive, and any necessary final adjustments are made.
Advantages of Onlay Restorations
Onlay restorations offer several advantages. They preserve more natural tooth structure compared to a full dental crown, meaning less healthy material needs to be removed during preparation. Onlays are durable and long-lasting, often remaining functional for many years, sometimes even decades, with proper care.
The materials used, such as porcelain and composite resin, allow onlays to be matched closely to the natural tooth color, resulting in an aesthetically pleasing restoration that blends seamlessly with the smile. They provide strong, stable support to weakened tooth structures, helping to protect against further damage and fractures from chewing forces. The precise, custom fit of onlays also helps prevent bacteria from seeping underneath, which can reduce the risk of future decay.
Maintaining Your Onlay
Proper care is important for ensuring the longevity of a dental onlay. Maintaining excellent oral hygiene, such as brushing at least twice daily with a soft-bristled toothbrush and fluoride toothpaste, helps prevent plaque buildup around the restoration. Daily flossing also removes food particles and plaque from between teeth and around the onlay.
Avoiding habits that can stress the restoration, like chewing on hard objects, ice, or sticky foods, helps prevent chipping or dislodgement. Regular dental check-ups and professional cleanings are also recommended; these visits allow the dentist to monitor the onlay’s condition and address any potential issues early. With consistent care, a dental onlay can remain functional and aesthetic for an extended period.