The present study is an educational randomized controlled trial., we selected 82 primary school students based on multistage cluster sampling. After receiving the necessary permits to conduct research and coordinating with local authorities, two girls schools and two boys 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 . However, 14 students 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 (Fig. 1). The inclusion criteria were a willingness to participate in the study, having the consent form signed by parents,and studying in the primary schools of Khomein city. The exclusion criteria were the withdrawal from the study, missing more than one educational session, and immigration from Khomein 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.  and Samiee Roudi et al. . Validity of the questionnaire was assessed through content validity in two quantitative and qualitative ways and with the assistance of ten professors and specialists in health education and promotion, school health, oral and dental health, and dentists. The content validity Index and ratio of the questionnaires (CVI and CVR) was evaluated by a panel of experts including 10 experts in health education,. 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 .The reliability of the questionnaire was measured through the Cronbach’s alpha coefficientin 30 students aged 6–12 years whose demographic characteristics were similar to those of the study population using the Stata 14 software .
The questionnaire was designed in six sections. Variables such as age, grade, gender, etc. were collected in the demographic section through the students file. The self-care section included 5 yes–no questions, and “I don’t know” as answers. The total score of this section was 5.For example, I clean my mouth and teeth myself (Yes,No, I don't know).The knowledge section contained 10 questions with three-choice answersFor example, what is the best way to clean the space between your teeth? (Toothbrush, Dental floss, 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 40.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 60 points. In each of the following situations, how sure are you that you can clean your teeth? a.Not sure at all; b. a little sure; c. pretty sure; d. very sure; e. totally sure).
The structural questionnaires 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 randomly selected as the cases and received training in 4 sessions (45–60-min) (Table 1). The schools considered for control received routine school training (Educating by health Instrutor). This study caused no conflicts of interest for any person or organization.
We used the animations related to oral health that are available in Aparat.com.
Exercising and recalling the learned material during games in a simple and child-friendly atmosphere causes an emotional arousal in children. Children participated in the practical training of oral health behaviors, as a source of self-efficacy, their success in proper functioning was considered. In addition,we used positive feedback and encouragement from educators and parents as a source of verbal encouragement for children. In this study, we taught students 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, after finishing the study, 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 from the children using a questionnaire( Apendix1) and entered into SPSS version 20. The questionnaires were completed in the form of structural 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.