Early childhood is a critical period for establishing lifelong oral hygiene habits, yet dental caries remain highly prevalent among preschool children worldwide. In Iran, over 88% of children aged 5–6 show signs of dental disease, emphasizing the urgent need for effective interventions. Parental knowledge, motivation, and capability play a pivotal role in shaping children’s oral health practices, as young children are often unable to maintain adequate hygiene independently. The COM-B model—focusing on Capability, Opportunity, and Motivation—offers a comprehensive framework for designing behavior change interventions. This study explores the application of a COM-B–informed educational program to improve oral health practices in preschool children. Findings suggest that addressing all three components simultaneously can enhance brushing behaviors, promote preventive care, and potentially reduce early childhood dental caries. The results provide evidence for integrating behavior change theory into early oral health promotion programs.