Why an inlay or onlay?
When a large, defective filling needs to be replaced, porcelain inlays and onlays can be an excellent way to restore the tooth. A porcelain inlay is small and covers the grooves of the teeth. An onlay is larger and covers one or more cusps or corners of a tooth.

Because these fillings are made in a laboratory, they are very strong and are bonded to the tooth, making the tooth stronger. Traditional fillings, whether made of amalgam (silver) or composite resin (tooth-colored fillings), do not add to the tooth strength. Inlays and onlays are definitely a more long term restoration than fillings.

What are inlays and onlays made of? Since both are used in areas of heavy chewing and grinding, they must be made from durable materials. They can be made from porcelain or composite resin chosen to match the color of your teeth, or a mixture of metals called an alloy. Alloys can be a mixture of metals like gold and palladium or nickel and chromium.

What are the treatment procedures for inlays and onlay?
The tooth is first prepared by removing portions of decay or damage. The remaining tooth structure is shaped in preparation for the inlay or onlay. An impression of the tooth is made along with opposing teeth and the bite. From this a plaster model is formed which is used for a custom fit matching the contours of the tooth.

Since both inlays and onlays are custom-made by a dental laboratory, a second appointment is needed for checking the fit and cementing the inlay or onlay permanently. At that appointment, any adjustments to the bite will be made. Polishing adds the final touch to this fine restoration.