Ensuring access to oral health care for children in low- and middle-income countries remains a persistent challenge, with little guidance on which interventions should be prioritized. The Healthy Kids Cambodia (HKC) program introduces an innovative model for school-based dental care, focusing on a core preventive package that combines daily brushing with 1,500 ppm fluoride toothpaste and targeted use of Silver Diamine Fluoride (SDF) to address cavities in primary teeth. To assess dental outcomes at the tooth level among 8- to 10-year-old children from two schools that implemented daily toothbrushing alongside Silver Diamine Fluoride applications at different intervals. This study followed a cohort of children in the late mixed dentition phase to observe how dental lesions progressed over time in two schools. Tooth-level data were recorded using the dmft and pufa indices. Both schools implemented daily toothbrushing (DTB) with training and supplies provided at the outset. In School One, Silver Diamine Fluoride (SDF) was applied at the start of the study, while in School Two, SDF was delayed until nine months later. Oral examinations assessed cavitated primary teeth at baseline and after 12 months, with teeth that remained carious or developed pulpal involvement classified as treatment failures. The analysis included descriptive statistics, and chi-squared tests were employed to compare the proportion of failed teeth between the two schools. Of the 521 children initially enrolled, follow-up data were obtained for 470 (90.2%). Delaying the application of Silver Diamine Fluoride in School Two was associated with a threefold higher risk of poor outcomes. Specifically, 10% of primary teeth in School One were classified as having unfavorable outcomes, compared with 33% in School Two. This study provides evidence on anticipated effect sizes that could guide the design of future stepped-wedge clinical trials aimed at validating a highest-priority oral health care package for Cambodian children. Implementing a care package that combines daily toothbrushing (DTB) with Silver Diamine Fluoride (SDF) has the potential to reduce negative outcomes, including dental infections, in primary teeth affected by caries.
