A master cast is a cast made to replicate a patient’s entire oral structures, including teeth, gums, upper and lower jaw, and soft tissue structures. Master casts are first created by taking an impression of the patient’s mouth, usually with a flexible putty or liquid that will form around the structures inside the mouth. The putty or liquid is left in the patient’s mouth long enough to harden into a semi-solid, elastic material that will maintain the shape of the patient’s oral cavity once removed. This process usually only takes a few minutes. The impression is then taken to the lab where it is filled with dental stone or plastic. Once this is done, a complete replication of the patient’s entire mouth has been created. Master casts can be used to manufacture a wide variety of dental prostheses, including but not limited to dental implants, bridges, crowns, and partial and complete dentures.