Background <p>School-based toothbrushing programs control children’s caries effectively. Given the superior efficacy of establishing a brushing routine with the program compared to relying solely on traditional education to develop autonomous brushing habits, the aim of this study pertains to how to motivate school staff to implement toothbrushing programs.</p> Methods <p>Twenty elementary schools participated in the school-based toothbrushing program in Taiwan. Action research and participant engagement were adopted for three years. Ninety-one school participants (including staff, principals, and school nurses) and five additional dental-related professionals received interviews, so there were 96 participants in total. Semi-structured interviews and field notes were taken. Ethnography was also adopted. The data underwent thematic analysis.</p> Results <p>Participants identified contextual factors such as interpersonal relationships, school atmosphere, optimism, school size, and time constraints influencing their motivation to implement the program. Some staff members demonstrated intrinsic motivation at the beginning. Other staff might be motivated by their peers through peer influences. Social influences were observed both within individual schools and across multiple schools. Staff also reported that the simplicity and adaptability of the program supported its integration into various school settings and indirectly enhanced their motivation.</p> Conclusion <p>Engaging intrinsically motivated staff who can inspire their peers through social influence, together with maintaining program simplicity and flexibility are key strategies for sustainable implementation of the school-based toothbrushing program.</p>