The World Health Organization recommended the use of the miswak in 1986, but in 2000 an international consensus report on oral hygiene concluded that further research was needed to document the effect of the miswak. Some of this further research has been done on a population of 203, and concluded, in turn, "that the periodontal status of miswak users in this Sudanese population is better than that of toothbrush users". Yet anothercomparative study conducted on a sampling of 480 Saudi Arabian adults found that "the level of need for periodontal care in the sample chosen is low when compared with the findings of similar studies undertaken in other countries. The frequent use of the 'Miswak' was associated with a lower need for treatment". A 2016 paper has been published comparing human DNA left on used miswak and toothbrushes, including the effect of time, to determine whether miswak is a reasonable source of DNA when found at crime scenes. The conclusion was that miswak contains a high enough quantity of DNA, and retained good DNA profiling; and when compared to toothbrushes, miswak is a reasonable source of DNA for forensic profiling. In addition, time of storage up to 4 months had no or little effects on results.
The use of the miswak is frequently advocated in the hadith. Situations where the miswak is recommended to be used include before religious practice, before entering one's house, before and after going on a journey, on Fridays, before sleeping and after waking up, when experiencing hunger or thirst and before entering any good gathering. In addition to strengthening the gums, preventing tooth decay and eliminating toothaches, the miswak is said to halt further decay that has already set in. Furthermore, it is reputed to create a fragrance in the mouth, eliminate bad breath, improve sensitivity of taste-buds and promote cleaner teeth.
A hadith concerning the miswak
It is often mentioned that the Islamic prophetMuhammad recommended the miswak's use. He is quoted in various hadith extolling its virtues:
Maintenance
A miswak should be one hand span in length when selected. If it becomes dry, it should be soaked in any water to soften the end bristles. The end should be cut afresh to ensure hygiene and should never be stored near a toilet or sink. The brush may be created by cutting Salvadora persica's branches instead of its roots; keeping in mind that the tree's roots can retain moisture more so than its branches. This favors more long-term usage.
Carrying
Many companies offer special cases for carrying miswak. Many of these companies also produce miswak itself. The main purpose of these cases is to protect and carry miswak in order to preserve its freshness. Plastic toothbrush cases are available at most drug stores and may be used for carrying a Miswak.