Porcelain & Resin Inlays and Onlays
As time goes by daily wear and tear on your teeth can cause old restorations (fillings) to go dark with age or fracture from decay. When this occurs these old fillings need to be replaced.
Porcelain or resin inlays and onlays are an aesthetic alternative to fillings. They look exactly like the rest of your natural tooth. Porcelain or resin inlays and onlays protect and restore large portions of the decayed tooth, much like a large filling.
An inlay covers more of the inside decayed part of the tooth and an onlay covers some of the inside but also more of the outer structure of the tooth.
Because they are made with porcelain or resin, they are customized to your natural tooth shade and look like your natural tooth. Porcelain or resin inlays and onlays are made from the same strong, tooth-colored material that is used for crowns and bridgework. A customized shade makes them virtually undetectable.
Original source: Library of the Academy of General Dentistry