摘要：The rate of dental caries and periodontal diseases in the world is still high, regardless of progress in the oral and dental hygiene. The natural toothbrush or chewing stick called “Mis- wak” has been used since ancient history. In this research the efficacy of Miswak in preventing dental caries was investigated and compared with the efficacy of toothbrush and tooth- paste. The analytical and clinical trial method was applied for this research among high sch- ool’s students in the city of Yazd, Iran, 2006. Three hundred eighty second year’s students (190 cases and 190 controls) were examined dentally. Then the Miswak was distributed to the case group and required trainings were given to both groups. After one year, the examinations were repeated. For analyzing the data one-way variance analysis test, Kai square, Paired t-test and two variable analyses were used. In the beginning of this study, there were no significant differences between two groups (cases and controls) regarding their dental situation and the frequency of brushing their teeth (p-value = 0.162). In addition, there were no significant differences in DMFT between the two groups. The data collected at the end of the study showed a significant increase in DMFT in the control group (p-value = 0.000). There was 55% increase in the rate of dental caries in control group compared to case group (0.89 before the study and 1.38 after the study). The risk of dental caries for each tooth in control group was 9.35 times more than case group (9.14% and 0.98% respectively). Dental caries rate was detected slightly less in the case group at the end of this study. This might be as a result of the antimicrobial effects of Miswak. A longer study with more cases is needed to prove this suggestion.
