Making teeth impressions is a core part of most dental treatments, as dentists will need to take a complete three-dimensional look at your face to prepare the correct dental treatments or design accurate crowns and veneers to suit your face.

Outside of making a diagnosis, dental impressions are used to make dentures, prepare brace treatments, to prepare prosthetics or to plan for dental surgery.

Several different materials are used for making and casting impressions depending on the situation. In some cases, the preference of particular dentists will determine the impression used, as different impression materials vary in consistency.

Plaster of Paris is a material that is still often used to create the cast after an impression is taken with another material, but has been used in the past to take impressions as well.

The problem with it as an impression material is that it is affected by saliva. This means that in some cases multiple impressions need to be taken. In general, it is an effective modelling material that takes very little time to create a solid albeit brittle impression.

Alternatively, there are less solid solutions such as sodium alginate. Alginates are available as either a liquid or a gel and create a semi-solid impression after being placed in the mouth for around a minute.

There are other materials available as well, including silicones, dedicated impression materials and impression pastes.

These materials are loaded onto an impression tray, which is pushed into teeth to make an impression until it sets. This step usually takes a minute or two before the tray is removed and a cast is made using a casting material.