What is an Inlay?
An inlay is a pre-moulded filling fitted into the grooves of a tooth and do not extend over the cusps of tooth. The patient is numbed using a local anaesthetic and the dentist drills the tooth to remove and clean out the decay in the tooth. This is one of the restorative methods used to repair a tooth after it sustains harm from injury or decay that does not affect the cusps of the tooth. The dentist takes an impression and sends it to a laboratory where the inlay is made. Inlays are manufactured from porcelain or composite resin material matching the colour of the tooth, and provide almost invisible dental restoration while repairing the chewing surface. Dental inlays are generally more durable than regular fillings made from composite and GIC.
What is an Onlay?
Onlays also fit inside the tooth, but extend onto the chewing surface of a back tooth to replace one or more cusps. In the past, onlays were made only of gold, but like inlays, more and more patients request a tooth-coloured onlay. Making the onlay of ceramic/porcelain allows the restoration to be bonded to the tooth. This bonding process may actually improve the strength of the tooth and help seal the onlay to the tooth.
Inlay and onlays in now made of Zirconium also.
It is difficult to determine when inlays or onlays can be used instead of crowns or caps. Ask your prosthodontist if you are a candidate for a tooth-colored inlay or onlay.