The misswak is an aromatic root of the small bush, Arraktree, (Salvadora persica L.), known as the toothbrush tree, which grows wild in the desert. The structure of this plant is extremely fibrous and contains sodium bicarbonate which protects it from micro-organisms usually invading the ordinary toothbrush. Certain astringents are also found, such as tannic acid which helps to protect the gums against infection. The misswak can also be used as a pacifier to prevent (1) smoking and (2) thumb sucking.