Dental fluorosis is a condition that results from the intake of too much fluoride during the period of tooth development, usually from birth to approximately 6-8 years of age.
Excess levels of fluoride can disturb the cell function of the enamel-forming cells (ameloblasts) which prevents the normal maturation of the enamel.
The severity of this condition ranges from very mild to severe, depending on the extent of fluoride exposure during the period of tooth development. Mild dental fluorosis is usually characterized by the appearance of small white areas in the enamel; individuals with severe dental fluorosis have teeth that appear stained and pitted ("mottled").
Source: based on GreenFacts
Enamel - Fluoride - Skeletal fluorosis
Español: Flurosis dental
Français: Fluorose dentaire