Inlays and Onlays are special types of fillings that are not formed in place like traditional fillings. Onlays are used when a cusp is involved. Both are used for relatively small fillings in which the tooth has relatively little initial damage. Inlays and Onlays involve impressions and labwork. The materials used can be very strong, and they bond well to tooth enamel. The impressions may be sent out to a lab for processing, in which case the patient will have a temporary restoration until the prosthesis returns from the lab for insertion. Or, the inlay/onlay may be processed in the office using a CAD/CAM system while the patient is waiting. That way, the patient can get a high-quality restoration with a minimum of visits to the office.