evaluation of permanent teeth extraction and related risk factors in patients of karaj central health city year in 91-92

introduction: because of prevalence of permanent tooth extraction and it’s related complication and due to bether alternative ways of tooth repair, this stady is done in health centers of karaj province to evaluate the etiologies and related risk factors. methods: survey was done by cross-sectional method on 240 patients. after extraction of data/factors like etiology of tooth remoral/ age/ sex/ educational leval/ cigarette somking and history of systemic disease were analayzed by spss software version 10. results: in present study, the most common reason of tooth extraction are decaying (72.1%), periodontal disease (17.5%), prosthesic reasons (7.5%), orthodontics causes (1.7%) and other reason (1.3%). (54.6%) were women and (45.4%) were men. in term of educational leval (45.8%) were in undergratuate level and (8.3%) had university degree. except sex, in all other factors p value was <0.05. conclusion: because caries and periodontal diseases were the most causes of permanent tooth extraction in referred people development of the tooth and oral health system including an efficient program that educate people abaut prevention is needed.  keywords: extraction of teeth ,causes of extraction