Health Financing and Functional Health Expenditure Allocation in Relation to Oral Health: A Longitudinal Ecological Panel Study of EU Member States Between 2016 and 2023

Background: Health financing decisions allocate resources across preventive and curative functions, but the relationship between system-wide expenditure composition and population oral health is unclear. This study assessed country-level associations between general healthcare expenditure and modeled oral disease prevalence in EU Member States. Methods: We assembled a 2016–2023 ecological panel for 27 Member States, matching Eurostat expenditure data with Global Burden of Disease (GBD) 2023 prevalence estimates for caries of permanent teeth (all ages) and periodontal diseases (age-standardized). Expenditure was examined at per-capita levels, functional shares, and the Preventive Expenditure Share (PES). Two-way fixed-effects models estimated within-country associations, adjusting for country and year effects and, in extended models, GDP per capita and dentist density. The complete panel comprised 216 country-years; primary HC.1 models included 192 observations from 24 countries. Results: In GDP-adjusted models, a 10% higher preventive expenditure level was associated with a 0.028 percentage-point higher caries prevalence (β = 0.291, 95% CI 0.028–0.554; p = 0.032); this association was not reproduced in the first-difference model and was specification-sensitive. Curative expenditure was positively associated with periodontal prevalence (β = 0.416, 95% CI 0.038–0.794; p = 0.032), equivalent to 0.040 percentage points per 10% expenditure difference, and this association was more consistent across reported sensitivity analyses. PES and functional expenditure shares were not associated with either outcome; the log P/C ratio was positively associated with caries, whereas its untransformed form was not. Conclusions: These ecological estimates describe associations between broad system-wide expenditure categories and modeled oral-health outcomes. They do not identify oral-health-specific spending or establish causal effects, and they cannot show that preventive dentistry is ineffective. Disease-specific expenditure, service delivery, and coverage data are needed to assess oral-health policy performance.