These types of restorations cover multiple surfaces of the tooth and are used when the tooth structure is not strong enough to support a regular filling. Just like a crown, inlays and onlays require two visits to the office to complete: the first to prepare the tooth for the inlay or onlay, and the second to deliver it. Inlays and onlays are often made from ceramic materials and can be bonded to the remaining tooth to restore its integrity and strength.