Fluoride Effects on Oral Bacterial Ecology

Fluoride, long recognised as a cornerstone of caries prevention, exerts a spectrum of biochemical and ecological effects on the oral microbiome. By inhibiting key glycolytic enzymes and impairing proton extrusion, fluoride reduces bacterial acidogenicity and disrupts pH homeostasis within biofilms. It also influences gene expression profiles, shifting community composition away from highly cariogenic species such as Streptococcus mutans towards less acid‐tolerant commensals. Concurrently, fluoride enhances enamel remineralisation and curtails demineralisation by forming fluorapatite on tooth surfaces, indirectly altering the habitat that sustains oral bacteria. Topical applications and controlled‐release systems aim to establish sustained fluoride reservoirs within the extracellular matrix, prolonging antibacterial action during acid challenges. Taken together, these multifaceted interactions shape both the structural integrity of dental hard tissues and the metabolic behaviour of resident microorganisms, underpinning global strategies—ranging from water fluoridation to advanced delivery vehicles—to manage caries risk and promote oral health.

Research from Nature Portfolio

Recent studies have employed precise biofilm sampling and analytical techniques to map fluoride retention across distinct oral sites following application of amine fluoride and sodium fluoride formulations. Findings reveal that the tongue coating serves as a major fluoride reservoir, sustaining elevated levels for up to two hours post-application, whereas palatal and buccal biofilms display faster clearance. These site-specific kinetic profiles indicate that chemical form influences both distribution and persistence of fluoride within the oral cavity. Such insights suggest that targeted formulation and delivery strategies can be optimised to maintain antimicrobial fluoride concentrations in regions most vulnerable to cariogenic activity.

Fluoride Effects on Oral Bacterial Ecology publication trend

The graph below shows the total number of articles in fluoride effects on oral bacterial ecology across all publications each year (not limited to Nature Index journals).

Technical terms

Biofilm: A structured community of microorganisms embedded within a self-produced extracellular matrix adherent to a surface.

Extracellular polysaccharides: Sugar polymers secreted by bacteria that form the scaffold of the biofilm matrix.

Acidogenicity: The capacity of microorganisms to produce organic acids through fermentation, contributing to enamel demineralisation.

Remineralisation: The process by which mineral ions, notably fluoride, calcium and phosphate, are redeposited into demineralised enamel.

Fluoride bioavailability: The extent and duration of fluoride ion presence in saliva and biofilm, determining its antimicrobial and anti-demineralisation efficacy.

References

1. THE RELEASE OF FLUORIDE IONS OF BIOACTIVE RESIN IN THE SOLUTION OF LACTIC ACID AND ARTIFICIAL SALIVA. Dentino Jurnal Kedokteran Gigi (2022).
2. Ação do fluoreto de sódio sobre a formação de depósitos, “in vitro”, por bactérias placogênicas [Title in english no available]. Revista da Faculdade de Odontologia de Porto Alegre (2021).
3. Dynamics of Fluoride Bioavailability in the Biofilms of Different Oral Surfaces after Amine Fluoride and Sodium Fluoride Application. Scientific Reports (2016).