Several factors influence the performance, durability, longevity, and expense of dental restorations, including: The components used in the filling material The amount of tooth structure remaining Where and how the filling is placed The chewing load that the tooth will have to bear The length and number of visits needed to prepare and adjust the restored tooth. Before your treatment begins, your prosthodontist will discuss with you all of your options, and help you choose the best filling for your particular case. To help you prepare for this discussion it may be helpful to understand the two basic types of dental fillings: direct and indirect. Direct fillings are fillings placed immediately into a prepared cavity in a single visit. They include glass ionomers, resin ionomers, and composite (resin) fillings. The prosthodontist prepares the tooth, places the filling, and adjusts it in just one appointment. Indirect fillings generally require two or more visits. They include inlays, onlays, veneers, crowns, and bridges fabricated with gold, base metal alloys, ceramics, or composites. During the first visit, the prosthodontist prepares the tooth and makes an impression of the area to be restored. The prosthodontist then places a temporary covering over the prepared tooth. The impression is sent to a dental laboratory which creates the dental restoration. At the next appointment, the prosthodontist cements the restoration into the prepared cavity and adjusts it as needed.