Metrics details. Dental caries are a common non-communicable disease among children. Prefectures focusing on promoting oral health policies may promote both, but the interaction effect of implementing both subsidy policies and S-FMR at the prefectural level on caries prevention has not yet been examined. We conducted an ecological study using two-wave panel data, prefecture-level aggregated data in Japan for and The effects of six interaction terms, each representing a unique pairing from the four independent variables, were individually calculated.
No interaction was found between S-FMR and the subsidy policy at both outcomes. High S-FMR utilization and no co-payment until children enter elementary school were associated with fewer deciduous tooth extractions. Peer Review reports. Dental caries is a common non-communicable disease affecting adults and children [ 1 , 2 ], and previous studies suggest its prevalence was associated with socioeconomic status SES [ 3 , 4 ].
Protecting children's oral health from economic inequaliies is a crucial issue in dental public health. One approach is the use of fluoride, such as tap water fluoridation or pit and fissure sealant application, which has been shown to be effective in preventing childhood caries [ 5 , 6 ].
Tap water fluoridation is recognized as one of the top 10 public health achievements of the twentieth century by the US Centers for Disease Control and Prevention [ 7 ]. In Japan, several municipalities intervene in children's oral health through school-based fluoride mouth-rinse program S-FMR.
Previous studies have suggested that S-FMR reduces dental caries among children [ 8 , 9 , 10 ]. Another measure to protect children's oral health is the introduction of universal health coverage into the dental care system to eliminate inequalities in dental care access [ 11 , 12 ].
