Differences Between Inlay and Onlay

Otherwise known as indirect fillings, inlays and onlays are restorative dental solutions for repairing minor and major tooth decay damage. Inlays and onlays differ in their purpose, size, placement and procedural alternatives.

Purpose

• Dentists use inlays to fill cavities in teeth. They use onlays when the tooth damage is too large or the destruction too extensive for an inlay to restore, such as when more than one cavity or point of decay exists within the same tooth.

Characteristics

• Inlays and onlays both fit within the grooves between the cusps, or tips, of the teeth. But inlays are smaller than onlays and fill only individual spots. Onlays extend up and over the cusps to the outside of the tooth, covering more of the chewing surface area.

Alternatives

• Dental inlays are an alternative to fillings but fabricated outside rather than inside the mouth, thereby providing improved fit, durability and resistance to wear. Dental onlays are an alternative to crowns, providing the same set of improved benefits. Onlays are particularly beneficial when the tooth destruction is not yet large enough to warrant a full coverage crown. Although onlays involve a more extensive reconstruction than crowns, they also conserve more of the tooth's structure.