From Polycausal Disease to “Paint-and-Go”: Evidence-to-Policy Drift in Early Childhood Caries, SDF “Magic Paint,” and the Risks of Delegation Without Deliberation

Early childhood caries (ECC) is routinely described as a complex, multifactorial disease shaped by biofilm ecology, host susceptibility, diet, behavior, and social context. Yet, a growing strand of public-health messaging and implementation practice increasingly treats ECC as a one-step problem solvable by a topical “magic paint” (most prominently silver diamine fluoride, SDF) and deliverable by non-dental or minimally trained providers. This commentary argues that the core contradiction—declaring ECC polycausal while operationalizing it as monocausal—drives a harmful evidence-to-policy drift: research designs favor short-term, easily marketable surrogate endpoints (e.g., “arrest” defined partly by SDF-induced black staining) and implementation strategies shift diagnosis and management to underprepared personnel without robust guardrails.Using a journal-style critical lens anchored in ROB-2, CONSORT, and STROBE principles, I examine recent Canadian work frequently cited to justify “paint-and-go” approaches, including open-label randomized trials of SDF application intervals and microbiome-focused substudies, and I integrate the delegation axis through the Canadian Caries Risk Assessment Tool (CCRAT) and its embedding into primary care workflows. While SDF and non-dental screening can be valuable adjuncts in a continuum of care, overselling them as substitutes for dentist-led diagnosis, pulpal assessment, and definitive rehabilitation risks institutionalizing a two-tier standard for children—especially for Indigenous and remote communities. I conclude with concrete research and policy guardrails: comparator-driven trials, multilevel modeling, lesion-specific sampling where mechanistic claims are made, patient-centered outcomes, defined referral timelines, and a dental-home–anchored pathway that treats SDF as a bridge—not a destination.