After obtaining written parental consent and demographic data, the study protocol is implemented. Oral examinations are conducted in the school infirmary by a pediatric dentist, under the researcher's supervision, using disposable materials. The number of teeth, caries and fillings, plaque index scores, and gingival health are recorded. Children and their parents then watch a 14-step toothbrushing instructional video in a separate classroom, in which a healthy 12-year-old boy demonstrates proper brushing behaviors with verbal instructions. Following the video, children practice brushing using a mirror and materials provided by the researcher. Performance is assessed using a 14-step tool scored from 0 to 3, and parents receive individualized feedback. For the peer video modeling group, a WhatsApp group is created, and parents are instructed to show the video daily before brushing. Assessments are conducted at baseline and at 1, 3, and 6 months using plaque and gingival indices.

After obtaining written parental consent and demographic data, the study protocol is implemented. Oral examinations are conducted in the school infirmary by a pediatric dentist under researcher supervision using disposable materials. The number of teeth, caries and fillings, plaque index scores, and gingival health are recorded. Children and their parents then watch a 14-step toothbrushing instructional video in a separate classroom, in which a 3D jaw model demonstrates proper brushing behaviors with verbal instructions. Following the video, children practice brushing using a mirror and materials provided by the researcher. Performance is assessed using a 14-step tool scored from 0 to 3, and parents receive individualized feedback. For the peer video modeling group, a WhatsApp group is created, and parents are instructed to show the video daily before brushing. Assessments are conducted at baseline and at 1, 3, and 6 months using plaque and gingival indices.

After obtaining written parental consent and demographic data, the study protocol is implemented. Oral examinations are conducted in the school infirmary by a pediatric dentist, under the researcher's supervision, using disposable materials. The number of teeth, caries and fillings, plaque index scores, and gingival health are recorded. Children and their parents then watch a 14-step toothbrushing instructional video in a separate classroom, in which a healthy 12-year-old boy demonstrates proper brushing behaviors with verbal instructions. Following the video, children practice brushing using a mirror and materials provided by the researcher. Performance is assessed using a 14-step tool scored from 0 to 3, and parents receive individualized feedback. For the peer video modeling group, a WhatsApp group is created, and parents are instructed to show the video daily before brushing. Assessments are conducted at baseline and at 1, 3, and 6 months using plaque and gingival indices.

Dental plaque accumulation was assessed using the Modified Silness-Löe Plaque Index (mPLI), a widely used tool for evaluating plaque presence on tooth surfaces, particularly suitable for pediatric and special needs populations. In accordance with the FDI tooth numbering system and expert consultation, six index teeth (3 buccal, 8 buccal, 14 buccal, 19 lingual, 24 buccal, and 30 lingual) were selected. Both buccal and lingual surfaces were examined. Each surface was scored on a 4-point scale (0 = no plaque; 1 = plaque detectable by probe; 2 = visible plaque; 3 = abundant plaque). The individual plaque score was calculated by dividing the total score by the number of surfaces examined. Scores were categorized as no (<0.1), mild (0.1-1.0), moderate (1.1-2.0), or severe (2.1-3.0) plaque accumulation.

Gingival health was assessed using the Silness-Löe Gingival Index, a validated tool used to evaluate gingival inflammation and overall periodontal health. Gingival inflammation was measured by gently probing four gingival surfaces of each selected tooth with a WHO periodontal probe, applying a force not exceeding 20 g. Each surface was scored on a 4-point scale (0-3). The individual gingival index score was calculated by dividing the total score by the number of surfaces examined. Scores were classified as no (<0.1), mild (0.1-1.0), moderate (1.1-2.0), or severe (2.1-3.0) inflammation.

Toothbrushing performance was assessed using a structured 14-step protocol designed to evaluate toothbrushing skills and independence in oral hygiene practices, based on national guidelines and relevant literature. Each step was scored on a 4-point scale (0 = not completed, 1 = completed with caregiver assistance, 2 = completed with verbal guidance, 3 = completed independently). The overall score was calculated by dividing the total score by 14. The protocol includes essential brushing steps, such as cleaning anterior teeth and right and left posterior teeth in both jaws. This tool enables the systematic assessment of brushing accuracy, skill acquisition, and level of independence in children.