An irreversible hydrocolloid consisting of salts of alginic acid, a colloidal acid polysaccharide obtained from seaweed and composed of mannuronic acid residues; used in dental impression materials.
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al·gi·nate 'al-jə-.nāt n a salt of alginic acid
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al·gi·nate (alґjĭ-nāt) any salt of alginic acid. Soluble alginates, such as sodium, potassium, and magnesium alginates, form a viscous sol that can be changed into a gel by a chemical reaction with compounds such as calcium sulfate, a property which makes them useful as materials for taking dental impressions. See also magnesium alginate, under magnesium.Medical dictionary. 2011.