A dental technologist (dental laboratory technician) is a member of the dental team who, upon prescription from a dental clinician, constructs custom-made restorative and dental appliances. A dental technologist (dental laboratory technician) is a member of the dental team who, upon prescription from a dental clinician, constructs custom-made restorative and dental appliances. There are four major disciplines within dental technology. These are fixed prosthesis including crowns, bridges and implants; removable prosthesis, including dentures and removable partial dentures; maxillofacial prosthesis, including ocular prosthesis and craniofacial prosthesis; and orthodontics and auxiliaries, including orthodontic appliances and mouthguards. The dentist communicates with the dental technologist with prescriptions, drawings and measurements taken from the patient. The most important aspect of this is a dental impression into which the technologist flows a gypsum dental stone to create a replica of the patient's anatomy known as a dental cast. A technologist can then use this cast for the construction of custom appliances. A fixed dental restoration is an appliance designed to replace a tooth or teeth that may have been lost or damaged by injury, caries or other oral diseases. These restorations are distinguished from other restorations by the fact that once they have been placed by a dentist the patient can not remove them.Such Restorations include; crowns, bridges, veneers, fixed implant restorations, inlays and onlays. Removable restorations are dental appliances to replace one or more teeth that have been completely lost. These restorations ideally remain stable in normal function but can be removed by the patient for cleaning and at night. Removable restorations are either retained by the patients soft tissue as in full dentures, anchored and stabilized by other teeth as with partial dentures and overdentures or on implant attachments as with implant retained overdentures and partial dentures. Orthodontic technologists make removable orthodontic appliances with wires, springs and screws on prescription from an orthodontist to either move teeth to form a more harmonious occlusion and aesthetic appearance of teeth or to maintain the position of previously moved teeth.