Inlays and onlays are custom restorations used to repair teeth that have suffered from decay or structural damage, often serving as an alternative to traditional fillings. While similar to fillings in function, they are designed to restore strength, stability, and aesthetics to a tooth that needs more support.

Inlays and onlays can be made from porcelain, gold, or composite resin, and are bonded directly to the damaged area of the tooth.

• An inlay fits within the cusp tips (the raised edges) of the tooth.
• An onlay covers a larger area, extending over one or more cusps to reinforce the tooth’s structure.

Unlike conventional fillings—which are molded directly into the tooth during a single appointment—inlays and onlays are custom-crafted in a dental laboratory for a precise fit. Once fabricated, the restoration is bonded securely to the tooth during a follow-up visit.

Traditionally, gold was the material of choice due to its exceptional durability. However, porcelain inlays and onlays have become increasingly popular, as they are both strong and color-matched to blend seamlessly with the natural teeth for a more aesthetic result.

Benefits of Inlays and Onlays

Unlike traditional fillings, which can sometimes weaken the natural tooth structure, inlays and onlays are bonded directly to the tooth surface, helping to restore and even enhance the tooth’s strength.

These restorations are known for their exceptional durability, often lasting 10 to 30 years with proper care. Because they are custom-made for a precise fit, they provide superior protection and a more natural appearance compared to standard fillings.

When tooth damage is too extensive for a filling but not severe enough to require a crown, an inlay or onlay offers an ideal middle-ground solution—preserving as much natural tooth as possible while restoring full function and aesthetics.

Inlay and Onlay Procedures

The inlay or onlay procedure is typically completed over two dental appointments—one to remove decay and take an impression, and another to place and bond the custom restoration.

The First Dental Visit

During the first visit, the dentist removes any decay or damaged tooth structure and carefully shapes the area for the restoration. An impression of the tooth is then taken to ensure a perfect fit and proper bite alignment. This impression is sent to a dental laboratory, where the custom inlay or onlay is fabricated. To protect the tooth in the meantime, the dentist applies a temporary sealant or filling until the permanent restoration is ready.

The Second Dental Visit

At the second visit, the temporary material is removed, and the new inlay or onlay is tested for fit, color, and bite accuracy. Once confirmed, the restoration is bonded securely to the tooth using a strong dental resin and then polished to a smooth, natural finish.

Results of Inlays and Onlays

Inlays and onlays provide a strong, stable, and long-lasting solution for teeth that require minor reconstruction or replacement of old fillings. With proper care, they can protect and preserve the natural tooth structure for many years.

Patients should continue practicing good oral hygiene habits, including brushing and flossing daily and scheduling regular dental checkups and cleanings. Routine care helps maintain both the health of the restored tooth and the longevity of the inlay or onlay.

Additional Resources

MedlinePlus
National Institutes of Health
Centers for Disease Control and Prevention
Eunice Kennedy Shriver National Institute of Child Health and Human Development
U.S. Department of Health and Human Services
WebMD