Dental impression

A dental impression is an imprint of hard (teeth) and/or suft tissues, formed with specific types of impression materials that is used in different area of dentistry including prosthetics (such as making dentures, inlays and plastic models), restorative, diagnosis and Oral and Maxillofacial surgery for both intra oral and or extra oral aims.

The required type of material for taking an impression and the area that it covers will depend on the clinical indication.

A correct takien dental impression will describ a part or all of a person's dentition and other areas of the oral cavity. The dental impression forms an imprint (i.e. a 'negative' mould) of those teeth and soft tissues, which can then be used to make a cast or 'positive' model of the dentition. This may be used for the fabrication of dentures, crowns or other prostheses and orthodontics.

An impression is carried out by placing a viscous liquid material into the mouth, usually in a customised dental impression tray. The material, usually an alginate, then sets to become an elastic solid, and, when removed from the mouth, provides a detailed and stable reproduction of teeth. Common materials used for dental impressions are sodium alginate, polyether and silicones - both condensation-cured silicones and addition-cured silicones, such as polyvinyl siloxane. Historically plaster of Paris, zinc oxide eugenol and agar have been used.

See also