Gold onlays or inlays are custom made in a laboratory and then cemented into place. While gold fillings are often the most expensive choice, many consider it the best filling material. Gold inlays are well-tolerated by gum tissues and may last more than 20 years.
Porcelain inlays or onlays and are custom created in a lab and then bonded to the tooth. They can be matched to the color of the tooth, resist staining, and are about the same cost as gold fillings. A porcelain restoration generally covers most of the tooth, making the filling nearly undetectable.