The Inlay and Onlay Difference

Inlays and onlays are both minimally invasive tooth restorations, but they're not exactly the same. There are some key differences between the two that make them used for slightly different purposes in restoring decayed or damaged teeth.

How are Inlays and Onlays Similar?

Inlays and onlays are made from materials such as porcelain, gold, or cured composite resins. They're customized to fit into a hole or cavity in a tooth, and are fixed in place with a bonding resin. Because inlays and onlays are made from a solid block of material, tooth impressions are traditionally used to mold the restoration. As a result, it typically takes two dental visits to have these kinds of restorations fitted and placed. Dental offices with CEREC technology will create and fit your inlay and onlay in one dental visit without impressions.

How are Inlays and Onlays Different?

Generally, onlays are placed over the cusp of a tooth. The cusps are the biting surfaces of a tooth that project up from the tops of molars; if you run your tongue over your molars, you can feel the cusps sticking up and forming hard bumps on the top of each tooth. In contrast, inlays are placed between the cusps, in the small depression in the center of the tooth's surface that is mainly used for chewing.

Because onlays can be made to cover multiple surfaces as well as the area between cusps, they can be used to treat teeth that are more extensively damaged. Many dentists will use an onlay as a more conservative restoration procedure rather than a crown. This practice will limit the removal of healthy tooth structure as a more conservative approach to restoring a healthy bite.

In most cases, what determines whether a damaged tooth is treated with an inlay, onlay, or another kind of restoration altogether, is the surface area of the damage. In terms of the amount of damage they can treat, inlays and onlays fall somewhere between fillings and crowns, so they're useful for mild to moderate cases of damage and decay.

Sandy Point Dental provides convenient same day restorations via CEREC technology. This advanced system allows our Lake Zurich restoration dentist the ability to create crowns, inlays, onlays and veneers in a single dental visit. Contact our office to schedule an appointment.