Work

Fluoride varnish application and the temporal evolution of supragingival microbiota in children with differential caries risk

Year: 2026

Type: article

Abstract: Background: Fluoride varnish is used to prevent early childhood caries, but its longitudinal ecological impact on the supragingival microbiome beyond enamel remineralization remains poorly understood, especially long-term. Objective: To characterize 24‑month supragingival plaque microbiome evolution in young children under biannual fluoride varnish, stratified by caries risk, and fluoride's ecological effect on microbial structure, interactions, and metabolism. Design: A total of 48 children were categorized into low‑, moderate‑, and high‑caries‑risk groups using the modified caries-risk assessment tool for preschool children (PSC-MCAT). All received fluoride varnish every six months. Supragingival plaque collected at five timepoints over 24 months. 16S rRNA sequencing assessed diversity, key taxa, co-occurrence networks, and PICRUSt2 metabolic pathways. Results: with suppressed abundance. Fluoride increased network complexity and negative correlations in moderate‑/high‑risk groups. Glycolysis, TCA cycle, and starch/sucrose metabolism were inhibited in the high‑risk group post‑intervention. Conclusions: Regular fluoride varnish reduces ecological disparities across risk groups, suppresses cariogenic taxa, and alters microbial interactions and carbohydrate metabolism, promoting homeostasis. High‑risk children may require more frequent interventions.

Source: Journal of Oral Microbiology

DOI: 10.1080/20002297.2026.2682471