A crown, or “cap”, can be placed on any tooth, front or back, and covers it like a jacket or cup. Crowns encase the whole tooth, all the way to the gum line. They can be made of porcelain, ceramic, or metal such as gold. They may even be ceramic covered metal. A crown is not a “filling”. A filling repairs a small portion of the tooth. With a filling, material (usually a composite) is used to fill in a small area of the tooth. Fillings don’t encompass the whole tooth as a crown does.