Equity or Two-Tier Care? Guardrails for Silver Diamine Fluoride and Delegated Early Childhood Caries Pathways

Early childhood caries (ECC) is a complex, multifactorial disease shaped by biofilm ecology, host susceptibility, diet and behaviors, and structural determinants of health. Silver diamine fluoride (SDF) is an effective non-restorative option for arresting cavitated lesions in many settings and can support access when definitive care is delayed. However, translating short-horizon "arrest" outcomes into broad policy claims-that SDF-first, delegated pathways can substitute for dentist-led diagnosis and comprehensive rehabilitation-risks institutionalizing a two-tier standard of care for children facing the greatest access barriers. This perspective critically appraises evidence-to-implementation pathways for SDF and delegated ECC management, using risk-of-bias and reporting guidance as interpretive tools and drawing on pragmatic regimen trials, microbiome substudies, oral health-related quality of life (OHRQoL) analyses, and implementation work including the Canadian Caries Risk Assessment Tool (CCRAT) in primary care. We explicitly distinguish what studies demonstrate (e.g., feasibility and short-term arrest differences by reapplication interval) from what they do not establish (e.g., long-term tooth survival, pulpal outcomes, definitive treatment completion, and equity impacts). We propose practical guardrails that position SDF as interim management within a continuum of care: dentist-led diagnosis and escalation when pulpal risk is suspected; time-bound referral pathways with completion tracking; protocolized follow-up aligned with lesion/risk status; outcome sets that extend beyond "arrest" to include pain, function, OHRQoL, tooth survival, and equity stratification; and lesion-site sampling plus preregistered analyses when mechanistic claims are advanced.