Prosthodontics: Alginate Impressions
What is Alginate?
Impression materials are often classified according to their properties.
A poorly executed alginate impression
What type of impression material is alginate?
Why is the setting reaction of alginate irreversible ?
What is a colloid? And a hydrocolloid?
Alginate goes through two phases before setting:
SOL formation, which is the stage at which it should be inserted in the mouth when
it is sufficiently fluid to record detail. No gelation should occur at this stage.
GEL formation is the stage at which fibrils are formed and alginate goes
through an irreversible setting process. It is after this stage that the tray should be removed.