This was a double-blind, parallel, pretest–posttest, controlled clinical trial with the allocation ratio of 1:1. The CONSORT statement is used as a guide to write this article [20]; see Additional file 2.
Ethical considerations
Participation in the study was voluntary and the mothers signed informed consent forms prior to participation in the study. The study was approved by the ethics committee of School of Dentistry, Tehran University of Medical Sciences (IR.TUMS.VCR.REC.1397.1126). It was also registered in the Iranian Registry of Clinical Trials (IRCT20131102015238N2).
Designing the app
The existing literature and the available media and mobile apps were evaluated aiming to find other apps in our field of research, inspiring designs for this app, and the required technical information to design it. Finally, we designed a simple app (without gamification) to promote oral-health knowledge of mothers using the best relevant evidence and guidelines according to the educational design principles. We have considered American Association for Pediatric Dentistry guidelines as well [21,22,23]. This app was designed for Android operating system with JAVA programming language in Android Studio version 3.1.4. The SQLite website was used to design and install the database, and DB Browser for SQLite version 3.10.1 was used to transfer data to the database. The designed app provided the mothers with oral healthcare information for their children such as oral hygiene, proper nutrition, fluoride intake, and dental visits. Also, the app could send a notification at 9 p.m. every night for the mothers reminding them to brush the teeth of their children. The app was evaluated by a group of oral medicine specialists, pediatric dentists and electronic learning and programming technicians, and the recommended modifications were made.
Gamification of the app
Another version of this app was designed using the gamification elements. In the gamified version of the app, toothbrushing for the child, frequency of toothbrushing, application of toothpaste, and daily amount of intake of sugary substances by the child were the key elements reinforced by gamification; the mothers were asked questions about these topics and received a feedback for each response. She would be rewarded in case of giving the correct answer. The acquired scores for each question would be summed and the total daily score of the mother would be displayed. In case of acquiring a high score, the background color of the app would change for 1 week, indicating achieving a higher level. Also, a progress bar was present on the top of the page showing the scoring process for the purpose of encouragement. The opinion of the experts was asked regarding this app, and the modifications were made accordingly. Both apps were piloted on 2–3 mothers and their opinions after 1 week of using the app were collected and applied.
The app would send a notification to the mother at 9 p.m. every night. Clicking on the notification would redirect the user to the scoring section. The app was designed such that it would not allow accessing the scoring feature more than once daily. Also, the mother had to enter the child’s name and gender when signing up in the app. Thus, every time that the mother would log in, questions and notifications would include the name of her child, in order to be more user-friendly. Also, a female avatar would appear for baby girls and a male avatar would appear for baby boys on the home page of the app.
Research environment and methodology
In order to assess the efficacy of the apps, an intervention was performed on mothers of preschool children presenting to the specialty clinic of Tehran School of Dentistry. The collection data of our study was begun in March 2019 and ended by June 2019. The inclusion criteria of this study included the mother possessing a smart phone and her child being 6 years old or younger. The mothers were randomly divided into two groups (Fig. 1), to use either simple app or the gamified app, using a simple randomization method done by a computer software (Microsoft Excel).
The random allocation sequences were done by MZ, the enrolment of participants and their assignments to interventions were done by SZM, and they were examined by MSH.
The mothers in both groups filled out a questionnaire prior to downloading the app. The questionnaire (Additional file 1) assessed the oral health knowledge of mothers (18 questions) and their self-reported practice regarding oral health of their children (5 questions). It also had a demographic section regarding level of education of mother, level of education of father, socioeconomic status of the family, child’s age, and mother’s age. Also, the plaque index (PI) of children was measured and recorded in the questionnaire. PI was measured using a dental explorer and a dental mirror. MSH examined the children according to the “Leo & Silness” modified dental plaque index [24].
If the tooth had no plaque, it was given score zero, plaque present at gingival margin only, score one, and abundant dental plaque covering more than gingival margin, score two. For each child, the average level of plaque for all teeth scores was taken into account.
The questionnaire was designed using the available valid questionnaires [25,26,27,28] and included a number of researcher-designed questions too. The content and face validity of the questionnaire was assessed by a group of 7 experts of community oral health and pediatric dentistry. All item Content Validity Indexes were more than 0.83. Moreover, 10 mothers were requested to fill out the questionnaire twice with a 2-week interval to assess its reliability; the coefficient of agreement for all questions was at least 0.85.
Mothers who were considered in the assessment of the reliability of the study were excluded from the main study. Mothers were first interviewed with the questionnaire and after that the PI of the children was measured and recorded in a form at the end of the questionnaire.
Next, the apps were downloaded on mobile phones of the mothers. The address bar of the app had customer service contact information, and the mothers were asked to contact the customer service in case of having a problem.
After 1 month, the mothers were contacted by phone and were requested to show up for free fluoride therapy. The same questionnaire was filled out again by the mothers and the PI of their children was measured again.
Sample size
Sample size was calculated to be 29 in each group considering the standard deviation of 2 for PI, study power of 80%, alpha = 5% and detection of 1.5 score difference between the two groups using the formula below:
$$n = \frac{{\left( {Z_{1 - \alpha /2} + Z_{1 - \beta } } \right)^{2} \left( {S_{1}^{2} + S_{2}^{2} } \right)}}{{\left( {\mu_{1} - \mu_{2} } \right)^{2} }}$$
Blinding
Participants were blind in the current study. We had not informed participants that there were two different apps; however, the participants inevitably knew whether the app there were using is conventional or gamified. In accordance, the examiner was blind as well.
Statistical analysis
Data were analyzed using PASW Statistics (Version 18). Descriptive data including percentage, mean and standard deviation were reported. The response to knowledge questions was dichotomized as correct and incorrect. Each correct answer was scored 1 and incorrect answers were scored 0. The maximum and minimum scores were 18 and 0, respectively. Regarding the five practice questions, the maximum and minimum scores that could be acquired were 14 and 0, respectively. Paired t-test was used to compare the pretest and posttest scores. The linear regression by the backward method was applied to assess the effect of demographic factors and type of intervention on the results.