Anti-fluoride propagandists often use the incidence of dental fluorosis as an argument against community water fluoridation. However, they exaggerate the problem by misrepresenting the issue in two ways:
1: They present the issue as if the figures for the incidence of dental fluorosis relate to the severe forms when they don’t. Most cases of dental fluorosis in areas using CWF are classified as questionable or mild. Yet the anti-fluoride people will present images of severe dental fluorosis which is never caused by CWF (see Dental fluorosis: badly misrepresented by FANNZ ). Severe forms are caused by excessive toothpaste consumption, high natural fluoride levels or industrial contamination. Never by CWF.
The figure below shows the incidence of the different dental fluorosis categories in New Zealand (data taken from 2009 New Zealand Oral health Survey – see Our Oral Health).
And here are some accurate images of dental fluorosis provided by the Centers for Disease Control and Prevention (CDC).
(Double click to enlarge)
2: They will then go on to claim that dental fluorosis is disfiguring and destroys the quality of life of the afflicted. Of course this may be true in countries where severe dental fluorosis occurs,* but not in countries like New Zealand where CWF is used.
A recently published study objectively determined the effect of dental fluorosis and dental decay on 5,474 North Carolina schoolchildren and their families – Effects of Enamel Fluorosis and Dental Caries on Quality of Life. It found no statistically significant association between dental fluorosis and oral-health related quality of life scores. Probably what one would expect because the incidence of dental fluorosis was about 28% and most of this was questionable or very mild.
But what about the effect of tooth decay on quality of life? In this case the results were statistically significant showing that dental caries does decrease the quality of life.
Their overall conclusions – a child’s caries experience negatively affects oral health-related quality of life, while fluorosis has little impact.
I think many of us can relate to this from our own childhood experience.
*The mainly poor quality IQ studies anti-fluoridation activists like Paul Connett love to quote were made in areas of high natural fluoride where dental and skeletal fluorosis is endemic. Such studies are not relevant to the issue of CWF, but they do raise in my mind the effect of severe dental fluorosis on quality of life, learning problems and hence possibly IQ measurements (see my article Confirmation blindness on the fluoride-IQ issue). Personally I think any disfiguring oral defect like bad tooth decay or severe dental fluorosis would effect a child’s quality of life and potentially cause learning defects and so drop in IQ.
In countries like NZ such effects on quality of life and learning are much more likely to result from bad dental decay than severe dental fluorosis. If anything, perhaps CWF actually reduces learning problems and potentially prevents decreases in IQ.
Another study invesdtigatign the influence of tooth decay and dental fluorsis on quality of life is described in the paper by Do, L. G., & Spencer, A. (2007). Oral Health-Related Quality of Life of Children by Dental Caries and Fluorosis Experience. Journal of Public Health Dentistry, 67(3), 132–139.
This also concluded that caries and less acceptable appearance showed a negative impact, while mild fluorosis had a positive impact on child and parental perception of oral health-related quality of life.
New report from the National Fluoridation Information Service – Dental fluorosis – is it more than an aesthetic concern? Its key findings are:
“Evidence does not indicate there are any health risks associated with CWF at the levels of 0.7 to 1.0 mg/L in New Zealand, and no severe dental fluorosis, or skeletal fluorosis, has been found. While fluoride is incorporated into teeth and bones, there is no robust evidence of toxic accumulation of fluoride in other tissues in the body. CWF in New Zealand has been found to not lead to anything more than very mild or mild dental fluorosis for a small “