Topical fluoride use in dental fluorosis: caries risk, fluoride toothpaste effectiveness, and whether fluoride avoidance is justified: a narrative review

Relevance. Dental fluorosis (DF) is an enamel hypomineralization caused by excessive systemic fluoride intake during critical periods of amelogenesis. It is endemic in regions with high fluoride levels in drinking water (>1.5 ppm), including the Moscow Region and the Republic of Mordovia in the Russian Federation, but may also occur in non-endemic areas because of alternative sources of fluoride exposure. Historically, teeth affected by dental fluorosis were considered resistant to dental caries; however, current evidence refutes this view and indicates an increased caries risk.

Objective: To assess whether restricting fluoride-containing oral hygiene products in patients with dental fluorosis is scientifically justified and to evaluate the benefits and risks of their use for caries prevention in this population.

Materials and methods. A literature search covering the past 30 years was performed across PubMed, EMBASE, MEDLINE, Springer, Wiley Online Library, ResearchGate, and eLIBRARY using the following search terms: dental fluorosis, dental caries, hypomineralization, fluoride, toothpaste, caries susceptibility, enamel defects, salivary buffering capacity, and dietary habits. Of the 265 identified articles, 26 relevant studies were selected for full-text analysis.

Results. Patients with dental fluorosis are at increased risk of dental caries and rapid lesion progression because of altered enamel structure, reduced mineralization, and increased enamel fragility. Caries prevalence increases with fluorosis severity regardless of fluoride concentration in drinking water. Topical fluoride use in children and adults with dental fluorosis is important for counteracting this increased caries risk. Topical fluorides do not worsen fluorosis and remain the main preventive measure for affected teeth after eruption.

Conclusion. Restricting topical fluoride use in dental fluorosis is not supported by convincing scientific evidence and may reduce protection against dental caries. Recommendations to avoid fluoride-containing toothpastes appear to stem largely from conflating the systemic pathogenesis of dental fluorosis with the topical effects of fluoride, as well as from outdated concepts.

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