Abstract: A container of toothpaste comprises two portions, one containing a stabilized alkali metal bicarbonate and the other containing an acid or acid salt which is reactive with the bicarbonate to produce carbon dioxide upon simultaneous dispensing of both portions of the toothpaste. Reaction of the bicarbonate and the acidic material, and resulting effervescence are avoided during storage by maintaining the two portions of the toothpaste in separated sections of the toothpaste container, from which they may be dispensed together. Upon dispensing, as by extrusion of both portions from a collapsible tube, they contact each other with little or no effervescent reaction at the interface of the two phases, but effervesce strongly during intimate mixing of the portions during toothbrushing. Preferably the toothpaste is extruded from the tube as an attractive plural-colored striped or variegated ribbon, with the different portions being differently colored to produce the striped or other plural-colored appearance.