Abstract
Miswak (Salvadora persica) is commonly used in Saudi Arabia and other middle Eastern countries as an oral hygiene tool. The purpose of this study was to evaluate the effect of freshness on the antibacterial action of 1, 5, 10 and 50% concentrations of miswak extract which were tested against six different microbes, using the blood agar ditch plate method. After 48 h of incubation there was no difference in antibacterial effect of freshly cut and 1-month-old miswak. At 50% concentration the extract was effective in inhibiting Streptococcus mutans, Streptococcus sanguis and Streptococcus faecalis, producing an inhibition zone of 2-7 mm. At 5 and 10% concentrations, the extract was effective only against Streptococcus faecalis. It is concluded that miswak (Salvadora persica) has an antibacterial effect at higher concentrations and there is no difference in the antibacterial effects of fresh and 1-month-old miswak.