Abstract
Miswak, a chewing stick, is obtained from Salvadora persica (Arak tree) roots and is commonly used in Saudi Arabia and other countries in the Middle East for oral hygiene. Several studies have demonstrated the antimicrobial effect of these sticks. The purpose of this study was to evaluate the antimicrobial effect of extracts of bark, pulp and entire S. persica in standardized experimental conditions at 1, 5, 10 and 50% concentrations, which were tested against five different micro-organisms using the blood agar ditch plate method. After 48 h of incubation variable antimicrobial effects were produced by bark, pulp and whole miswak extracts. At 10 and 50% concentrations all extracts were effective against Streptococcus faecalis. At 5% concentration only bark and whole miswak extracts were effective against S. faecalis. Bark and whole miswak extracts were effective against Streptococcus mutans at 50% concentration. Staphylococcus aureus, Staphylococcus epidermidis and Candida albicans were not inhibited by any concentrations of the three extracts. S. persica has an antimicrobial effect at higher concentrations and there is difference between the bark and pulp of miswak. The bark is effective against S. faecalis and S. mutans at 5, 10 and 50% concentrations and the whole miswak is more effective compared with bark or pulp separately.