Which of the following acts as an astringent?

 # Which of the following acts as an astringent?

A. Thymol

B. Glycerin

C. Zinc chloride

D. Liquoron

The correct answer is C. Zinc chloride.

Zinc chloride is a commonly known astringent used in various ways as in with retraction cords, gum paints and for management of oral ulcers. 

• Astringents : These are substances that act by precipitating proteins on the superficial layer of mucosa and make it mechanically stronger. Examples are alum or aluminum potassium sulfate (KAl (SO4)2), A1C13 and zinc chloride (ZnC12) 

• Styptics: These are concentrated forms of astringents, which cause superficial and local coagulation. Examples are ferric chloride and ferric sulfate (Fe2 (SO4)3) 

• A1C13 and ferrous sulfate are preferred astringents among dentists because of minimum tissue damage. 

• Because of the caustic action of zinc chloride on the oral tissues, it is not the preferred chemical for gingival retraction although it is still used for management of oral ulcers.