"Fillings" are the most common type of dental restoration. Restorations of this kind are used to replace tooth structure that is missing due to decay, deterioration of a previously placed restoration, or fracture of a tooth. Teeth can be filled with gold, silver amalgam, or tooth-colored materials called composite resin fillings. Today, metal-free fillings are available that are safe and similar to natural tooth structure both in appearance and function. Composite restorations can be contoured to the exact bite, look completely natural, and help prevent fractures on teeth.