An inlay is like a “processed” filling made outside of the mouth. An onlay is similar but larger, covering more of the tooth like a mini crown. Inlays and onlays last longer than fillings and do not require as much tooth removal as a crown. They can be made of gold, reinforced composite, or porcelain. Gold has been used for over 75 years with excellent success. It has excellent wear resistance, is kind to the opposing teeth and never breaks. Unfortunately it is not very esthetic and therefore is best used in nonvisible areas. Porcelain has been used for the last 15 years. Initially they had a high fracture rate but better bonding and stronger porcelains have reduced the fracture rate to 5% in 5 years. However, porcelain can wear the opposing teeth. It is very esthetic. Reinforced composite is as hard as tooth structure, very esthetic and kind to opposing teeth. Most all inlay/onlays are made in a dental laboratory from an impression but some can be fabricated in the dental office. Delmarva Dental Services makes all types of inlay/onlays.