According to the CDC, Oregon has the 8th lowest incidence of tooth destruction due to “tooth decay or gum disease” when isolating the 65+ population despite only 27.4% of all Oregonians drinking fluoridated water. In fact, the states with the lowest rates of water fluoridation have the least amount of tooth destruction with a positive .52 correlation. Only 8.4% of Hawaii’s population receives fluoridated water, yet Hawaii has the lowest incidence of tooth destruction according to CDC’s own data.
Could there be an economic reason for this? I ran correlations on state GDP, water fluoridation, and tooth destruction, finding the data to be spurious. A state’s economic status did NOT bear a close relationship to water fluoridation levels or tooth destruction.
I did find high correlations between water fluoridation rates and tooth destruction, meaning the states with the highest fluoridation rates had the highest rates of tooth destruction—these are most of the states that meet the Healthy People 2010 goal of fluoridating 75% of the population’s water. The Brunelle and Carlos study of 1990 showed that cavity rates did not vary much in states with high water fluoridation rates because of the spillover effect from the transportation of fluoridated beverages to nonfluoridated areas. Although people in these states are being exposed to water fluoridation indirectly and directly, the rate of tooth destruction is higher for the entire state.
How can tooth destruction happen? Normal bone matrix is made with very strong hydroxyapatite. The inclusion of fluoride creates fluorohydroxyapatite, a substance more capable of resisting bacterial decay, but much weaker structurally. The American Dental Association in its fluoride fact paper cites that water fluoridation contributes to a 10% greater rate of fluorosis, which is considered the level where fluoridation is considered excessive. The Institute of Medicine Committee on the Scientific Evaluation of Dietary Reference Intakes’ review of water fluoridation led to the optimal range of .7 to 1.2 ppm. This range was formulated assuming that dietary fluoride would contribute an additional .5 ppm. Added together, 1.7 ppm was considered the optimal “safe” level of fluoride before the “threshold for a problem of public health significance.” This is also the highest rate considered safe for infants. It’s very easy for a person to consume more than 1.7 ppm of fluoride after drinking fluoridated water calibrated to a different area through the spillover effect, ingesting fluoridated dental care products (children) or fluoride supplements, or eating a nonaverage diet where the level of fluoride is greater than .5 ppm.
The Institute of Medicine also states: “Many studies conducted prior to availability of fluoride-containing dental products demonstrated that dietary fluoride exposure is beneficial, owing to its ability to inhibit the development of caries in both children and adults (Russell and Elgrove 1951). “ Well, let’s take a look at the Russell and Elgrove study.
The authors first studied a NY city where rates of 1 ppm showed a reduction of 8%, a barely statistically significant amount. An examination of a CO city with rates of 2.5 ppm, twice the recommended water fluoridation rate, resulted in a 14% decrease in dental events. The authors also concluded: “[The findings] are not adequate to support a hypothesis that use of a fluoride water results in improved health of periodontal tissue.”
The ADA claims that there are no credible studies that show a negative health effect of fluoride whereby they simply discredit any study that shows any negative effect. I found on PubMed several credible studies that showed fluoride increases the virulence of Strep mutans and increases risks for people with chronic kidney disease. The ADA claims that dialysis occurs with nonfluoridated water so it’s not a concern, but they ignore the fact that people with chronic kidney disease ingest water apart from dialysis. There are no studies referencing multiple myeloma except for the University of Tokyo study on cancer that the ADA dismisses as poorly designed. The problem with comparing nonfluoridated areas to fluoridated areas in time regression analysis, which CDC often cites, is the growing spillover effect from widespread beverage distribution.
The CDC claims that water fluoridation saves $38 for every $1 spent. This study used data from the 1980s using a discount rate of 4% despite inflation rates ranging from 12-16%. The study also assumes that one hour of wages is lost for every tooth cavity filled—5 cavities in total. This wage rate does not take into account people that can see a dentist on a day off or use paid days-off. Reading the study, the $38 figure represents a best-case scenario. The worst-case scenario shows a benefit of $3.52 using a discount rate of 8%. If we used real inflation rates from the 1980s, there would be no benefit under the worst-case scenario.
A Portland resident will spend $51.64 on water fluoridation over a 75-year lifespan using Portland’s budget estimates. Using this $38 cost-benefit claim, we would generate $1,962 in dental savings per person. If we assume that lost wages and dental costs average $170 (CDC study uses $72 in 1995 terms) to get a cavity filled, we would save enough to fill 11.54 cavities. A slight overestimation since the average person never gets 11.54 total cavities filled over their lifetime. Assuming that we fill 5 fewer cavities as the CDC study claims and a cavity costs $170 to fill, we save 16x in relation to what we invest under the best-case scenario. If we have cost overruns beyond budget estimates, we experience an increase in tooth destruction, or we experience less than a 5-cavity reduction, then this best-case scenario would not manifest.
The cost-benefit could be negative if we experience more tooth destruction from water fluoridation. If we ignore tooth destruction and we actually achieve optimal levels of cavity prevention, then the total we save on our overall dental care is only 3.4% at best using national dental statistics of $333 spent per person/year. We do not save money on more expensive procedures related to periodontal tissue or from extreme tooth decay caused by lack of access to dentists.
I will admit that reducing cavities is important because of toxic elements in fillings. However, if we experience an increase in tooth destruction, then the amount of metal placed in our mouths from caps will be much higher than what a few cavities would involve. The best preventative measure is access to dental care, better dental practices, and a proper diet. I would much rather invest in these measures, even if they cost more, because they are the only proven way of decreasing cavities, periodontal disease, tooth destruction, and myriad other health problems we face.