An alginate impression is used in dentistry to make an exact replica of the patient’s teeth, gingiva, and surrounding tissues in the mouth.
The alginate dental impression forms an imprint (i.e. a ‘negative’ mould) of those teeth and gums, which can then be used to make a cast or ‘positive’ model of the patient’s dentition.
Alginate impression material begins as a powder. When mixed with water, a thick pasty material, similar to cake frosting, appears.
The dental impression tray is filled with the viscous alginate impression material and placed over the teeth, one arch at a time.
The alginate impression material sets after 30 to 60 seconds in the patient’s mouth.
Cold water prolongs the setting time of alginate, while warm water shortens the set time considerably. Once the alginate impression material has set, it becomes solid.
When ready to create the final study models, the operator will fill the set alginate impression material with a stone mixture.