The aim of this study was to determine the effect of oral and dental health education on combining dental caries preventive behaviors in students and the specific goals are: determine the demographic and background characteristics of students in two groups: intervention and control, determination The relationship between knowledge, attitude and behavior with demographic variables, determine and compare the mean score of knowledge, attitude and preventive behaviors in students about dental caries before, immediately and two months after the intervention. In this semi-experimental study, female students of elementary school in KootAbdollah town were selected through multistage cluster sampling in the first semester of the academic year of 2017-2016. The criteria for entering the study are as follows: Residence in Koot Abdollah, primary and secondary education, and willingness to participate in the study, as well as exclusion criteria include incomplete completion of the questionnaire, reluctance to continue studying and transfer to other schools. The data collection tool was a demographic and subscale characteristics questionnaire and a standard questionnaire for assessing the knowledge, attitude and behavior regarding the prevention of dental caries that was completed in three stages before, immediately and two months after the intervention. The experimental group received two sessions of combination training, which included the use of presentation, PowerPoint, practical and role play.