The miswak (miswaak, siwak, sewak, Arabic: سواك or مسواك) is a teeth-cleaning twig made from the Salvadora persica tree (known as arāk, أراك, in Arabic). It is reputed to have been used over 7,000 years ago. The miswak's properties have been described thus: "Apart from their antibacterial activity which may help control the formation and activity of dental plaque, they can be used effectively as a natural toothbrush for teeth cleaning. Such sticks are effective, inexpensive, common, available, and contain many medical properties". It also features prominently in Islamic hygienical jurisprudence.