Their effervescence helps to remove unhealthy tissue. Examples are hydrogen peroxide and perborate. Astringents , which cause local blood vessels to contract and thereby reduce swollen tissues. Examples are alcohol, zinc chloride, zinc acetate, alum, and organic acids such as tannic, acetic, or citric acid. Anodynes , which alleviate pain and soreness.
Examples are phenol derivatives, oil of wintergreen and eucalyptus oil.
Buffers , which reduce the acidity in the mouth resulting from fermentation of food debris by microorganisms. Examples are sodium perborate and sodium bicarbonate. Deodorizing agents, which neutralize odor from decomposing oral debris. An example is chlorophyll. Detergents , which reduce surface tensions, thereby allowing ingredients to become more soluble, and which also degrade bacterial cell walls, causing the bacteria to lyse.