Chemical effects of chewing sticks made of Salvadora persica.

Objective: The chewing sticks are widely used in many regions of Asia and Africa as a traditional tool to maintain oral hygiene. Salvadora persica L. (S. persica), also known as Arak or Miswak, a member of the salvadoraceae family. Chewing sticks, made up from S. persica, have chemical antibacterial properties and mechanical effects. The study aimed to investigate possible chemical effects of S. persica on dental plaque, sub-gingival microbiota and gingival inflammation. In order to achieve this, we inactivated some sticks through boiling to be used as inactive, but mechanically comparable control sticks.

Methods: In a double-blinded crossover trial, 24 patients with mild-to-moderate periodontitis were randomly allocated to use either fresh activated Miswak or inactivated Miswak for 3-week period. Plaque index (PI), gingival index (GI), visual plaque index (VPI) and bleeding on probing (BOP) were evaluated before and immediately following the experimental period. Sub-gingival plaque samples were analysed using DNA-DNA hybridization technique. The study was repeated with the participants switching the type of Miswak they used after a 7-week of "washout" period.

Results: There were no significant differences in the microflora after using active and inactive Miswak. Sixteen species of bacteria showed an increase (P < 0.05) after the usage of inactive Miswak, as compared to pretreatment values. No species showed a similar change after the use of active Miswak. There were no significant differences between active and inactive Miswak regarding the registered clinical variables.

Conclusion: This study has not shown any clinical effect of the chemically active Miswak, but there was a tendency towards an effect on the microflora.