THE Miswak was known before Islam, but Islam added a religious perspective to its usage. Prophet Muhammad (peace be upon him) recommended Muslims to clean their teeth using a Miswak every day; especially upon waking up, when performing ablution, before prayer, when reciting the Qur'an, before sleeping, when entering the house, and when the mouth has a foul odor. The Prophet (peace be upon him) said: “Ten things are part of one's natural disposition: Trimming the moustache, growing a beard, (using) the Miswak, snuff up the nostrils using water, cutting the nails, washing hands, plucking armpits, shaving pubic hair, and conserving water.” (Sahih Muslim) Furthermore, the Prophet (peace be upon him) highlighted its importance, saying: “If it were not that it would create hardship for my people, I would have ordered them to use the Miswak with every ablution and with every prayer.” (Al-Bukhari) Medical discoveries The Miswak, a natural tool for brushing teeth, is taken from roots and branches of particular desert trees. It differs from one region to another, but in Arabia and Asia it is taken from the Arak tree. This is the most famous variety, which was used by the Prophet (peace be upon him). Its scientific name is Salvadora Persica. It is an upright evergreen small tree or shrub. The leaves are small, oval, thick and succulent with a strong smell of cress or mustard. The Miswak is also obtained from other trees. In Africa, for example, it is cut from Lime and Orange trees, and in America some are cut from the Senna tree. The Arak tree has been scientifically studied and the following is a summary of it: Health effects of Miswak Miswak is composed of a compact group of minute natural fibers that perform the same function as a normal toothbrush does except that it is made of natural rather than plastic fibers. Miswak's natural toothpaste contains over 10 natural chemical compounds considered essential for good oral and dental hygiene. They are: fluoride, silica, tannic acid, resins, alkaloids (salvadorine), volatile oils (sinigrin), sulfur vitamin C, sodium bicarbonate, chlorides, calcium, benzylisothiocyanate (BIT), and others including salicylic acids, sterols, trimethylamine, saponins, flavenoids. Some of these components are stain removers and teeth whiteners, some protect teeth against caries, some are bactericidal and antiseptic, some help in healing and to repair tissues, some promote remineralization (building) of tooth enamel, and some give the pleasant taste and smell. Cell damages Results of cytotoxictests showed no cytotoxic (cell-damaging) effects from using freshly-cut Miswak. However, the same plant used 24 hours after cutting did contain harmful components. Based on these findings, researchers recommend cutting the used portion of the Miswak after it has been used for a day and preparing a fresh part. How to use Miswak should be whitish-brown in color; a dark brown color indicates that the Miswak is no longer fresh. If a stick is dry, the end for chewing should initially be soaked in fresh water for 24 hours. It should be noted that soaking for unduly long periods causes loss of active constituents and diminishes the therapeutic properties. Before Miswak is used, the end should be washed with water. It is then chewed repeatedly until the fibers stand out like the bristles of a toothbrush. These fibers should be trimmed every 24 hours. While using Miswak, like a normal toothbrush, it should be brushed away from the gums and care should be taken to avoid damaging the soft tissues of the mouth. Common mistakes in using Miswak u The end is either too thin or too thick. u Keeping it in the mouth while doing other things. u Not cutting the end every day. u Forgetting that teeth have five faces (inner, outer, two sides, and biting/chewing face), and only using Miswak to clean the outer faces.