摘要:Background: Oral health is one of the most important dimensions of individual health, so in order to assess the status of oral health in a community, it is necessary to conduct various epidemiological studies at different stages to determine the effectiveness of prevention and oral health programs in a community. The aim of this study was to determine some of the factors associated with dental caries in primary school students in Hamadan in 2019.Methods: In this case-control study, information about students with dental caries and controls was extracted by referring to schools in the four education districts of Hamadan (A girls' school and a boys' school were selected from each district). The total sample size was 980 people and 30 cases and 90 controls were selected from each school. For determining dental caries status a final year dental student examined the students. Logistic regression model was used to evaluate the risk factors for the disease. All analyses of this study were analyzed using Stata software, version 14.Results: A total of 240 cases and 740 controls were studied in this study. The mean dmft in primary school students in Hamadan was 1.86 ± 2.92. Among them, the first and second grade students had the highest caries rate. The results of the logistic regression model showed that the risk of tooth decay in people with severe toothache is almost twice as high as that in people who do not have toothache. This rate is more than 1.5 times higher for students whose fathers are workers than for those whose fathers are self-employed. Also, as the number of family members increased, the chances of developing tooth decay increased linearly. The odds of tooth decay in people who do not brush and floss are 2.84 and 2.13, respectively, more than people who brush and floss three times a day.Conclusion: In our study, having severe toothache, lack of parental supervision over the children's oral health, employment and education of parents, family dimension, not using toothbrush, flossing and mouthwash, excessive consumption of sweets, lack of regular visits to the dentist, and low dairy consumption were associated with tooth decay.