Astringents are useful in gingival retraction and are topically applied chemicals that constrict tissues. They are also known as hemostatic agents because they are able to constrict small blood vessels and produce mild coagulation. Aluminum chloride and ferric sulfate are the two most common astringents/hemostatic agents. Racemic epinephrine is an effective astringent and vasoconstrictor that must be use with carefulness for patients with hypertension or cardiac problems, because it can rise blood pressure and increase the heart rate. Astringents and hemostatic agents are used to control bleeding in gingival sulcus before taking a PVS impression, but it should be washed off the tooth since it could affect the surface detail of
