Alginate impression material is available in the powder form.
It is mixed with water when impression is to be made. It is one of the most widely used dental impression materials.
Alginate impression material is widely used because of the:
Ease of mixing and manipulation.
Minimum requirement of equipment.
Flexibility of set impression.
Accuracy of the impression.
Alginate impression materials have following disadvantages:
Cast can only be made in gypsum or gypsum products.
The transfer of details to gypsum is not as good as agar or rubber impression materials.
Packaging of the Alginate Impression Material:
They are sold into two types of packaging:
1. Pre weighed package.
2. Bulk package.
The pre weighed packages are made up of plastic or metal foil. They contain enough material for single full arch impression. This kind of packaging minimizes the moisture contact with powder and extends the shelf life of the alginate impression material.
Bulk packages are available in plastic container that may contain powder in large quantities. When an impression is to be made, one or two spoons of the powder as per need is taken from the packet, and mixed with water to make impression.