Dental hygiene (debris index) and dental caries are common in school-age children, dental caries is damage to the hard tissues of the teeth caused by acids present in carbohydrates through the intermediary of microorganisms present in saliva. The purpose of the study was to relate knowledge, consumption of snacks and tooth brushing actions to dental caries and debris index in 5th grade students of SD Muhammadiyah Meruyung Depok. The type of research used was analytical observational with cross sectional design. The population in this study were students of SD Muhammadiyah Meruyung Depok with a total of 90 students in grade 5. The sample in this study was 90 students taken by total sampling. the instrument used was a questionnaire. Data analysis was carried out by univariate analysis, bivariate analysis (chi-square test) and multivariate analysis (logistic regression). The results showed that there was a significant relationship between knowledge of snack consumption, snack consumption habits and tooth brushing actions on the incidence of dental caries. There is a significant relationship between snack consumption, snack consumption habits and tooth brushing actions on the debris index in students of SD Muhammadiyah Meruyung Depok. Of the three independent variables, it is known that the snack consumption variable has a significant contribution to the occurrence of dental caries with a p-value = 0.007 <0.0, which means that respondents with poor snack consumption habits will be at risk of 96.539 times developing dental caries compared to respondents who consume good snacks, known as the 95% C.I. value for EXP (B) (1.049-15.374). Of the three independent variables, it is known that the variable of tooth brushing action has a significant contribution to the debris index score with a p-value = 0.000 <0.05, which means that respondents with poor tooth brushing action will have a risk of 543,054 suffering from debris index compared to respondents with good tooth brushing action, known 95% C.I. for EXP (B) (26,498-11129,274).
Keywords: Snack consumption, knowledge, action, dental caries, debris index