Inlays and onlays are indirect restoration, which means they are made in the laboratory after dentist’s preparation and then cemented in place in the tooth. This is an alternative to a direct restoration, made out of composite or glass ionomer, that is built up within the mouth. Inlays and onlays are used in molars or premolars, when the tooth has experienced too much damage to support a basic filling, but not so much damage that a crown is necessary.