Agar impression material is obtained from: (A) Seaweed, (B) Fungi, (C) Bacteria, (D) Plants
Answer is A. Agar, a polysaccharide extracted from certain types of seaweed, is the main active ingredient in the material, while water is the major constituent in the agar impression material. A small percentage of borax is added to strengthen the gel. Since borax is a potent retarder for the setting of gypsum, an accelerator such as potassium sulfate is added to counteract the effect of borax.