Excess absorbed fluoride may impair normal development of enamel in the pre-eruptive tooth.
This will not be apparent until tooth eruption, which will be more than 4-5 years after exposure.
In Europe, skeletal fluorosis has only been reported in workers in the aluminium industry, fluorospar processing and superphosphate manufacturing (Hodge and Smith 1977).
SCHER concludes that there are insufficient data to evaluate the risk of bone fracture at the fluoride levels seen in areas with fluoridated water.
The SCHER opinion states: Genotoxicity studies In general, fluoride is not mutagenic in prokaryotic cells, however sodium and potassium fluoride (500-700 mg/L) induced mutations at the thymidine kinase (Tk) locus in cultured cells at concentrations that were slightly cytotoxic and reduced growth rate.
Figure 1 shows a plot of the Community Fluorosis Index versus the daily fluoride dose/kg bodyweight (Butler et al. Similarly, enamel fluorosis may occur in non-fluoridated areas, in conjunction with the use of fluoride supplements and in combination with fluoridated toothpaste (Ismail and Hasson 2008).
Fluoridated toothpaste has been dominating the European toothpaste market for more than 30 years.