In the present interventional study, 82 primary school students were selected based on multi-stage cluster sampling. After receiving the required clearance for conducting the research and coordination with local authorities, two girl schools and two boy schools were randomly selected from governmental schools. Each grade was considered a cluster and 4 participants were randomly selected from each grade using class rosters. In the next stage, using simple randomization, one boy school was selected as the case school and another school was considered as the control school. The same process was applied to girl schools. The sample size, based on the results of the previous studies, was α=0.01 and β=0.1, and the attrition of 20% was 48 participants in the case group and 48 in the control group (20) . However, 14students did not complete the study. Thus, the data for 82 students including 38 in the case group and 44 in the control group were considered for analysis. The inclusion criteria were willingness to participate in the study, having the consent form signed by parents, and studying in the primary schools of X city . The exclusion criteria were withdrawal from the study, missing more than one educational session, and immigration from X city.
The data collection tool was a researcher-made questionnaire containing questions on self-care, knowledge, attitude, behavior, and self-efficacy, which was developed based on the questionnaires designed by Mohammadi Zeidi et al. (21) and Samiee Roudi et al. (22). The content validity of the questionnaires (CVI and CVR) was evaluated by asking a panel of experts including 10 experts in health education, school health, oral and dental health, and dentists. A CVR of above 0.62 was considered as acceptable. Regarding CVI, the experts evaluated each item in terms of relevance, clarity, and simplicity Based on the results, all were considered as acceptable since all values were above 0.79 (23) . The reliability of the questionnaire was measured through the Cronbach’s alpha coefficient in 30 students aged 6-12 years whose demographic characteristics were similar to those of the study population using the Stata 14 software (24) .
The questionnaire was designed in six sections. The variables like age, grade, sex, height, weight, etc. were collected in the demographics section. Private and personal questions were avoided in this part. The self-care section included 5 yes-no questions, and “I don’t know” as answers. Each correct answer received a score of 1 and a score of 0 was given to wrong and “I don’t know” answers. The total score of this section was 5. I clean my mouth and teeth myself (a . Yes, b. No. c. I don't know). The knowledge section contained 10 questions with three-choice answers For example, what is the best way to clean the space between your teeth? a. Toothbrush, b. Dental floss, c. Mouthwash). A score of 1 was given to correct answers, totaling a score of 10. The attitude section had 13 questions in a 5-point Likert scale from 1 to 5 with a total score of 65. For example,I think eating milk is very important for dental health ( I totally agree, I agree, It doesn't matter,I disagree, I completely disagree) Behavior was assessed with 8 questions in a 5-point Likert scale with a total score of 32. For example, I wash my mouth after eating sweets and food (Always, Most of the time, Sometimes, Rarely, Never). In adition, fourteen questions were used to assess self-efficacy in a 5-point Likert scale, scoring a total of 70 points. In each of the following situations, how sure are you that you can clean your teeth?When you are very tierd ( I'm not at all sure, I'm a little confident, I'm pretty sure, I'm pretty sure, I'm pretty sure). The questionnaires were completed in the form of interviews to explain more details to the students and provide appropriate answers. After coordination with school principals and conducting a pretest, two schools were randomly selected as the cases and received training in 4 45-60-min sessions (Table 1). The schools considered for control received routine school training. This study caused no conflicts of interest for any person or organization.
In this study, watching animations was used as a substitute for traditional training techniques. Exercising and recalling the learned material during games in a simple and child-friendly atmosphere causes an emotional arousal in children. Children’s involvement in practical education of oral and dental health behaviors, their success in correct performance, and regular display of the behavior based on a plan can be considered as the sources for self-efficacy. Moreover, positive feedback and encouragement of the instructors and parents provide a source of verbal persuasion for children. In this study, the students were taught about nutrition and its effect on oral health.
Written parental informed consent, as well as written child assent, was obtained from all students participating in this study . In addition, the training materials such as the booklets and CD (Animation ) were given to the control group. This study was registered under the ethics code of IR.ARAKMU.REC.1395.446.
Pre and post-intervention data were collected using a questionnaire ( Apendix1) and entered into SPSS version 20. The questionnaires were completed in the form of interviews to explain more details to the students and provide appropriate answers .The Kolmogorov-Smirnov test was applied to check normal data distribution and proper statistics were used accordingly. Chi square test, paired and independent t test, Mann-Whitney U test, and Wilcoxon signed-rank test were used for statistical analysis.