Direct fillings are fillings placed into a prepared cavity in a single visit. They include silver amalgam, glass ionomers, resin ionomers, and composite (resin) fillings. The dentist prepares the tooth, places the filling, and adjusts it in one appointment.

Indirect fillings generally require two or more visits. They include inlays, onlays, and veneers fabricated with gold, base metal alloys, ceramics, or composites. They are used when a tooth has too much damage to support a filling but not enough to necessitate a crown. During the first visit, the dentist prepares the tooth and makes an impression of the area to be restored. The dentist 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 dentist cements the restoration into the prepared cavity and adjusts it as needed.