Socioeconomic inequalities and the economic burden of dental caries: A longitudinal simulation analysis across forty countries

<b>Background</b><br/>In 2024, World Health Organization (WHO) member states endorsed the Bangkok declaration, prioritizing oral diseases within universal health coverage and non-communicable disease agendas, and calling for prevention-oriented, primary care-led systems. This study aimed to: 1) explore the healthcare costs of managing dental caries between the ages of 12 and 65 years across income quintiles in 40 countries, and 2) estimate the potential reduction in direct costs from non-targeted and targeted oral health-promoting interventions.<br/><br/><b>Methods</b><br/>A cohort simulation model was developed to estimate the direct costs of dental caries over time for different income quintiles across 40 countries. National-level DMFT (dentine threshold) data, the relative likelihood of receiving an intervention (such as a restorative procedure, tooth extraction and replacement), and clinically guided assumptions were used to populate the model. A hypothetical group of upstream and downstream preventive interventions were applied either uniformly across all income groups to reduce caries progression rates by 30% or in a “levelling-up” fashion with the greatest gains seen in the lowest income group. <br/><br/><b>Results </b><br/>The population-level direct costs of caries from 12 to 65 years of age varied between US317.8 million in Slovenia to US$182.6 billion in China. The highest per-person costs were in Switzerland at US$55,932 and the lowest in Jordan at US$6,399. The per-person direct costs were highest in the lowest income quintile across the 40 countries. Inadequate preventative oral care for lower-income groups results in 50% higher total treatment costs. With the uniform application of preventive measures across all income quintiles, the greatest reduction in per-person costs for caries management was seen in the lowest income quintile across all countries. With a levelling-up approach, cost reductions in the lowest income group ranged from US$4,083 in Vietnam to US$43,106 in Switzerland. <br/><br/><b>Conclusion</b><br/>Lower income groups experience a greater health and economic burden from dental caries. Early, targeted preventive interventions, such as twice daily bushing with fluoridated toothpaste, water fluoridation, oral health education, and school programs, within a life-course, equity-driven framework, can reduce costs, mitigate disease burden, and advance global oral health equity.<br/>