Sugar-Sweetened Beverage Taxation Exposure and Dental Caries Prevalence Among South African Adolescents: A computed Control Analysis of Fiscal Policy and Hygiene Service Demand

South Africa's Health Promotion Levy, introduced in 2018, was the first national sugar-sweetened beverage tax in sub-Saharan Africa, yet its implications for dental caries among adolescents remain unexamined. Because no post-implementation caries surveillance data are available for the adolescent cohort, the analysis is framed as a methodological and policy-modelling contribution rather than an empirical evaluation. The paper specifies a donor pool of comparable middle-income jurisdictions, defines a caries prevalence outcome from repeated cross-sectional oral health surveys, and derives a treatment-effect estimator that accommodates the gradual pass-through of excise duties to retail prices. A service-demand component translates estimated caries reductions into hygiene visit requirements and therapist workforce implications. The framework is calibrated against published price-elasticity estimates for sugar-sweetened beverages in South Africa and against caries increment data from adolescent cohorts. The analysis identifies three conditions under which a computed control design can credibly attribute caries change to the levy: stable survey instruments, a donor pool uncontaminated by concurrent sugar taxes, and a pre-treatment window of sufficient length. It concludes that the levy's dental benefits are plausible but currently unquantified, and that the principal obstacle to evaluation is the absence of a caries surveillance system linked to fiscal implementation dates.