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Alginate
Also called: irreversible hydrocolloid, impression material
A powder mixed with water to take impressions for study models and trays.
Alginate is a powder that you mix with water into a smooth paste, load in a tray and seat in the mouth, where it sets in a few minutes. Cold water slows the set; warm water speeds it. It loses or gains water as it sits, so it should be poured in stone quickly, usually within about 15 minutes.
How to spot it
- A tub or bag of powder with a scoop and water measure, a flexible rubber bowl and a wide spatula.
What it is used for
- Measure powder and water exactly, mix firmly against the bowl, load the tray and seat it.
- Rinse and disinfect the impression right after removal, then wrap it and pour it soon.
Safety and care
- Avoid breathing the powder dust when you scoop and mix.
- Disinfect impressions with an intermediate-level (TB claim) disinfectant compatible with alginate.
Related
Sources: Boyd LD, Mallonee LF, Wyche CJ. Wilkins' Clinical Practice of the Dental Hygienist, 14th ed. Jones & Bartlett, 2024, CDC. Guidelines for Infection Control in Dental Health-Care Settings, 2003. MMWR 2003;52(RR-17)