Assessing the Impact of a Social Media-Based Educational Intervention Using WhatsApp Video Messages on Dental Caries Prevention Knowledge, Oral Hygiene Practices, and Attitudes Toward Dental Health Among Primary School Children Aged 10-12 Years in Public Schools in Cairo Governorate, Egypt: A Quasi-

STUDY DESIGN AND RATIONALE

This is a quasi-experimental pre-post study with a non-equivalent control group. The study compares WhatsApp-delivered video-based educational intervention (intervention group) to standard school activities (control group) among primary school children aged 10-12 years in Cairo, Egypt.

Quasi-experimental design was chosen because randomization at the individual level was not feasible in the school setting. To minimize contamination between groups, children were assigned by grade level: all Grade 5 students form the intervention group, and all Grade 6 students form the control group. This approach reduces daily interaction between groups while maintaining comparable baseline characteristics.

The intervention is based on social cognitive theory, which emphasizes observational learning, self-efficacy, and behavioral modeling. Videos were selected to demonstrate proper techniques, provide positive role models, and build confidence in children's ability to practice good oral health behaviors.

INTERVENTION DESCRIPTION

Intervention Group (Grade 5, n=75):

Children will receive 6 educational videos about dental health via a closed WhatsApp group over 6 weeks (one video per week, posted every Monday at 4:00 PM).

Video Content and Delivery Schedule:

Week 1 - "Why Do We Need Teeth?" (3:58 minutes) Topics: Dental anatomy and tooth functions (chewing, speaking, smiling), consequences of tooth loss, importance of caring for baby teeth, introduction to tooth decay. Format: Animated educational video with Arabic voiceover.

Week 2 - "The Right Way to Brush Our Teeth" (4:17 minutes) Topics: Step-by-step brushing technique (circular motion), brushing all surfaces (outer, inner, chewing), tongue brushing, frequency (twice daily), duration (2 minutes), replacing toothbrush every 3 months. Format: Animated demonstration with catchy song and visual instructions.

Week 3 - "Foods That Harm Our Teeth" (3-4 minutes) Topics: How sugary foods and drinks feed bacteria to produce acid causing cavities, sticky foods, frequent snacking, identifying unhealthy foods (candy, soda, cookies), limiting sugar intake. Format: Interactive animated video with visual categorization.

Week 4 - "Foods Good for Our Teeth" (3-4 minutes) Topics: Calcium-rich foods (milk, cheese, yogurt) strengthen teeth, crunchy fruits and vegetables naturally clean teeth, water rinses the mouth, importance of balanced diet for oral health. Format: Animated educational video.

Week 5 - "Why Do We Go to the Dentist?" (2-4 minutes) Topics: What happens during a dental checkup (examination, cleaning), professional cleaning removes plaque, importance of preventive care, recommended visit frequency (every 6 months), making dental visits fun instead of scary. Format: Animated story or live-action video showing positive dental visit experience.

Week 6 - "Fun Tips for Healthy Teeth" (2-3 minutes) Topics: Review of key messages, creative ways to make brushing fun (brushing to a song for 2 minutes, family brushing time, friendly competitions), establishing morning and evening routines, celebrating healthy smiles, positive reinforcement and encouragement. Format: Musical video with children singing and performing.

All videos were selected based on: high-quality production (clear audio/video), evidence-based content (aligned with WHO and American Academy of Pediatric Dentistry guidelines), age-appropriateness (10-12 years), cultural relevance (Arabic language, Egyptian context), engaging format (animation, demonstration, music), appropriate length (2-5 minutes), positive tone (encouraging, not fear-based), no commercial content, educational value, and positive viewer feedback.

WhatsApp Group Management:

A closed WhatsApp group named "Healthy Teeth Friends" will include 75 intervention group children and approximately 45 parents (60%) who optionally choose to join, with the researcher as group administrator.

Each weekly post includes: friendly greeting in Arabic, 2-3 sentence introduction about the week's topic, YouTube video link, encouraging message, and relevant emoji. Mid-week reminders will be sent to children who have not viewed the video within 48 hours. The researcher will monitor the group daily, respond to questions within 24 hours, and document intervention fidelity including date/time of posting, number of views within 48 hours, number of questions and reactions, and responses provided.

Control Group (Grade 6, n=75):

Children will continue their usual school and home activities without receiving study-related educational materials during the 8-week study period. They will be informed that a second assessment will occur in May. After completing post-intervention assessments, the control group will be invited to a separate WhatsApp group to receive all 6 educational videos for ethical reciprocity.

OUTCOME MEASURES

Primary Outcome:

Dental Health Knowledge

• Change in Dental Health Practices Score [Срок оценки: Baseline (Week 0) and 8 weeks after baseline]