# Fluoride Levels in Austrian Drinking Water Are Insufficient for Effective Caries Prevention

## TL;DR

Austrian drinking water has low fluoride levels, which are not enough to prevent tooth decay, with most areas below the recommended 0.5 mg/L.

## Contribution

The study provides updated evidence on fluoride levels in Austrian drinking water, highlighting insufficient concentrations for caries prevention.

## Key findings

- 98% of Austrian municipal water samples had fluoride below 0.5 mg/L, insufficient for caries prevention.
- One quarter of municipalities had fluoride levels under 0.1 mg/L.
- One Tyrolean municipality had fluoride levels exceeding the recommended threshold, potentially harmful.

## Abstract

Background/Objectives: Fluorides play a well-established role in preventing dental caries, primarily by enhancing enamel resistance and inhibiting demineralization. Drinking water is among the most important sources of systemic fluoride intake. In 1993 and 2007, national analyses of Austrian drinking water revealed fluoride levels below 0.5 mg/L in almost all regions, which is insufficient for effective caries prevention. The present study aimed to re-examine the fluoride concentration in Austrian drinking water. Methods: Drinking water was collected in a total of 1985 Austrian municipalities. Fluoride concentration was measured by a fluoride-selective electrode. Results: The average fluoride concentration in the measured water samples ranged between 0.1 and 0.27 mg/L, depending on the region. The analysis revealed that 98% of the municipal drinking water samples contained fluoride at concentrations below 0.5 mg/L. In almost one quarter of Austrian municipalities, the fluoride levels amounted to less than 0.1 mg/L. The fluoride concentration in the drinking water of one Tyrolean municipality exceeded the recommended threshold. Conclusions: The results of the study reveal that the fluoride concentration in Austrian drinking water is generally too low to provide effective prevention against dental caries, affecting nearly all municipalities. Notably, the drinking water of one municipality reached potentially harmful fluoride levels. These findings could be used as a basis for targeted and individual fluoride supplementation, as well as for national or area-specific guidelines.