Inlays and onlays are partial porcelain crowns. Inlay is an indirect restoration fitted to a cavity in a tooth and cemented into place. An onlay is the same except that it restores a larger portion of the tooth including the cusp.
If the decay is even more extensive, a full porcelain crown is needed. Inlays and onlays are called indirect restoration because they are fabricated outside the tooth, and then placed on the tooth on a separate visit.
The tooth is prepared by removing the large existing old filling, or large decay and if necessary, filling in any deep holes or missing corners of the tooth. We may use any of a variety of filling materials to rebuild the tooth, such as composite resin or similar material.
We make an impression of the prepared tooth and place a temporary restoration. We send the impression to the lab for fabrication of final restoration. On the second appointment, we remove the temporary restoration, and place the final inlay/onlay. Minor adjustments maybe necessary for a perfect fit. Once we are satisfied with the fit, the inlay/onlay is permanently cemented.