Socioeconomic inequalities in unmet dental care needs in Spain.

Objective: Socioeconomic inequalities in access to dental care remain a critical public health challenge in Spain, where adult coverage is limited and largely financed through out-of-pocket payments. This study aims to estimate the magnitude of socioeconomic inequality in unmet dental care needs among the Spanish adult population in 2024 and to decompose the contribution of its determinants. Methods: A cross-sectional analysis was conducted using data from the 2024 Spanish Living Conditions Survey (ECV). The analytic sample included 32,425 adults who reported a perceived need for dental care in the previous 12 months. Socioeconomic position was measured using equivalised disposable household income. Income-related inequalities were quantified using the Concentration Index (CI) for relative inequality and the Slope Index of Inequality (SII) for absolute inequality. Furthermore, a Wagstaff decomposition analysis was performed to isolate the specific contribution of multidimensional factors such as material deprivation and housing tenure. Results: Among individuals with perceived need, 10.44% reported unmet dental care needs, with economic constraints identified as the overwhelming barrier (78.9%). The analysis revealed a robust pro-poor gradient, indicated by a Concentration Index of -0.361 ( Conclusion: The findings confirm that the "Inverse Care Law" persists in the Spanish dental healthcare system, driven fundamentally by structural economic vulnerability rather than demographic factors. The current model fails to protect the most deprived groups. Policy interventions must prioritize the expansion of public coverage and implement targeted financial protection mechanisms to effectively reduce these inequities.