Inlays & Onlays

When more than half of the tooth’s biting surface is damaged, Drs. Bowne and Holden may recommend an inlay or onlay.

What are inlays/onlays?

Inlays and onlays can be made of porcelain or gold. These restorations are bonded to the damaged area of the tooth. An inlay (which is similar to a filling) is used inside the cusp tips of the tooth. An onlay is a more substantial restoration, but extends out over one or more of the cusps of the tooth.

Traditionally, gold has been the material of choice for inlays and onlays. In recent years, however, porcelain has become increasingly popular due to its strength and color which can match the natural color of your teeth.

How are they applied?

Inlays and onlays require two appointments to complete the procedure. During the first visit, the filling being replaced or the damaged or decaying area of the tooth is removed and the tooth is prepared for the inlay or onlay. To ensure a precise fit and bite, an impression of the tooth is made and sent to our lab for fabrication. The dentist will then apply a temporary restoration on the tooth and a subsequent appointment will be scheduled to cement the restoration.

At the second appointment, the temporary filling is removed. Drs. Bowne and Holden will then make sure that the inlay or onlay fits correctly. If the fit is satisfactory, the inlay/onlay will be bonded to the tooth with a strong resin and polished for a smooth finish.


Traditional fillings can reduce the strength of a natural tooth by up to 50% . As an alternative, inlays/onlays that are bonded directly onto the tooth using special high-strength resins, can actually increase the strength of a tooth by up to 75%. As a result, they can last from 10 to 30 years. In some cases, where the damage to the tooth is not extensive enough to merit an entire crown, onlays provide an excellent alternative.