Lesion-Level Clinical Trajectories of Early Childhood Caries During Nano-HAp-Based Home Care: A Retrospective Longitudinal Study

Abstract

Early childhood caries (ECC) affects approximately 57% of children under age six in North America and represents the most prevalent chronic disease of childhood. While fluoride varnish remains the endorsed prophylactic standard under guidelines from the American Academy of Pediatric Dentistry (AAPD) and the American Dental Association (ADA), a clinically meaningful proportion of caregivers decline fluoride-based interventions, creating an evidence gap regarding fluoride-free alternatives in high-risk pediatric populations. This retrospective longitudinal study tracked 314 carious lesion sites in 35 de-identified pediatric patients (mean age 38.4 months) over 18 months following initiation of a multicomponent, fluoride-free home care protocol anchored by nano-hydroxyapatite (nano-HAp) toothpaste, complemented by pit-and-fissure sealants and xylitol adjuncts. Lesion trajectories were classified per International Caries Detection and Assessment System-II (ICDAS) criteria at four follow-up intervals. At 18 months, 51.7% of lesion sites were arrested or reversed and 22.3% progressed; outcomes were inversely correlated with lesion severity at baseline and positively associated with protocol compliance. ICDAS 1–2 lesions demonstrated arrest rates exceeding 55%, whereas ICDAS 4–5 sites showed predominantly progressive behavior. Findings suggest that within a structured, compliance-monitored framework, nano-hydroxyapatite (nano-HAp) home care can stabilize early enamel lesions in fluoride-refusing families, though it does not substitute for professional-grade fluoride prophylaxis in advanced disease. The data will be of particular interest to pediatric dentists, dental hygienists, and pediatricians engaged in preventive caries management for high-risk preschool-age children in the United States.