Background: Early childhood caries (ECC) is one of the most common chronic diseases in children and remains unevenly distributed across populations. It is associated with pain, impaired function, and long-term health consequences. Although advances have been made in understanding its aetiology and prevention, important gaps in evidence limit progress in prevention, early detection, and equitable care. Objective: To examine current evidence on ECC and identify key research gaps across biological, behavioral, social, and health system domains. Methods: This narrative review draws on peer-reviewed literature addressing ECC epidemiology, pathogenesis, risk factors, diagnosis, management, and service delivery. The literature was examined to identify areas where evidence is limited, inconsistent, or insufficient to inform clinical practice and public health policy. Results: Research on ECC remains uneven across levels. Longitudinal evidence linking microbiome dynamics, host susceptibility, and lesion progression is limited, restricting causal understanding. Genetic and epigenetic contributions are incompletely defined, particularly in diverse populations. Although socioeconomic gradients are well established, integrative models connecting structural determinants with biological mechanisms are scarce. Emerging diagnostic tools, including biomarkers and artificial intelligence, lack robust evidence demonstrating improved clinical or behavioral outcomes. Implementation research addressing scalability, cost-effectiveness, and equity impact is underdeveloped, especially in low-resource settings. Long-term systemic and developmental consequences of ECC remain insufficiently characterized. Conclusions: Addressing ECC requires integrated and equity-oriented research frameworks that bridge biological, social, diagnostic, and implementation domains. Clarifying these gaps is essential to inform coherent prevention strategies and reduce persistent disparities in child oral health.
Cheng et al. (Mon,) studied this question.