Variability of Drinking Water Fluoride and Dental Health in Estonia

Fluoride is a natural element found in various concentrations in natural waters. Ingestion of fluoride in the drinking water reduces the prevalence of dental caries due to the increase in tooth mineralization. However in high doses of fluoride, toxic effect occurs.

Objectives: The aim of the study was to measure the fluoride content in public water supply systems in Estonia and to assess the dental health of children in corresponding areas.

Methods: All public water supply systems serving at least 100 inhabitants were included into the study. The study included 70.6 % of Estonian population.

In total, 735 water samples from 44 towns and 473 smaller settlements were taken from the tap water and fluoride concentration was measured colorimetrically using SPADNS method. In 531 12-year-old children DMFT index and fluorosis were evaluated.

Results: Fluoride content in water samples varied in a wide range between 0.01 – 6.95 mg/l. National limit (1.5 mg F-/l) was exceeded in 15 % of samples. Over 7.3 % of study population are exposed daily to high-fluoride water, mainly in West-Estonia. Half of the population is consuming water with optimal fluoride content (0.5-1.5 mg/l). Over 40% of the consumed water has low fluoride content (up to 0.5 mg/l). A database for the fluoride levels of drinking water in Estonian towns and settlements was established.

The average value of DMFT index is 2.36 ±2.17, varying from 1.8 to 4.05 in different regions and increasing in correlation to the decrease of the fluoride content in drinking water. Dental fluorosis was diagnosed in 29.8% (13.7 – 56.9%) of the examined children.

Conclusions: The obtained data can be used for planning dental care and prevention of dental caries and fluorosis in diffrent regions of Estonia.