Posted by mattdds on September 27, 2003, at 14:15:59
In reply to Re: Fluoride ....matt and jan » tealady, posted by Larry Hoover on September 27, 2003, at 12:39:39
Hey Larry,
Good to hear from you again!
>>Methinks you may have "dental student credulity disorder". <grin>
Hey, this is a real disorder you're making fun of! And yes, I suspect I do meet some of the DSM-IV criteria for it. Is there any cure short of dropping out of dental school? I gotta pay the loans back somehow.
First of all, you are right about one thing. the evidence is not *always* pro-fluoride. But then again, when is the evidence *always* pro-anything? I would say with a good degree of confidence that the vast majority of evidence shows a great deal of caries reduction (usually 50%) with appropriate levels of fluoride. If you search hard enough, you can find an article to support nearly any pet hypothesis.
As an anecdotal finding, all the older practitioners I talk to in the clinic say that the "golden age" of dentistry was before fluoridation. Now, due to lower levels of decay, you are starting to see dentists offer treatments like tooth whitening and veneers or other esthetic "treatments".
The abstract you pasted was investigating *fluorosis*, and how it related to DMFT and DMFS. It was not studying fluoridation at appropriate levels. It studied 3 areas. One with natuaral levels of fluoride, and two with approximately 50% above the recommended amount. No population with the recommended 1 ppm was included. So it's difficult to extrapolate from this. Also, the sample size was small, compared to say, an n of the size of Grand Rapids, Michigan.
>>The link between thyroid hypofunction and fluoride exposure is quite firm in humans, but most of the evidence has been presented in papers in Russian and Chinese
Possible. But why are North American researchers so unaware or unconvinced of this? I should be honest here and say that I've never investigated this. I'd be curious to know at what levels fluoride has been shown to induce hypothyroidism. Are they similar to what is used in fluoridated water? Are there any epidemiological studies showing increases in hypothyroidism that is clearly linded to fluoridation of public water? If you're dismissing large epidemiological studies, how do we know that certain individuals are susceptible, as you say? Case studies? Little cameras inside their thyroid that watches the fluoride do its harm?
>>What underlies the "1 ppm fluoride is safe" argument appears to be the idea that there is a toxic threshold, below which there is no adverse effect. That, however, is not true. The toxic effect is continuous, and variable in different populations exposed to the same dose
First of all, keep in mind *natural* water contains fluoride, sometimes up to 0.5 ppm or more.
Second. I have trouble with your argument that fluoride causes disease along a continuum. Couldn't you say the same thing of nearly any substance - including ones like selenium, vitamin A, and zinc? This is even more true with things like psych drugs. We are giving psychiatric drugs to a certain population. We are weighing the relative risk of adverse events to benefits and deciding that the benefits outweigh the risks. Same with fluoridation. It is a drug (although again, it is found in natural water at 50% of "fluoridated" water), but we've found a level where the benefits greatly outweigh the risks.
But if you can show me some convincing evidence that hypothyroidism is significantly on the rise from fluoridation, I would be happy to agree with you that public water should not be fluoridated. Perhaps, in that case, systemic fluoride supplements would be an alternative (to protect people susceptible to getting hypothyroidism from fluoride). On the other hand, supplements would place a huge economic burden on people (public fluoridation is dirt cheap compared to individual supplementation), and treatment adherence would be a problem.
>>Looking at whole-population parameters will not reveal the effect on thyroid function in susceptible individuals, because it is a rather rare effect
So it's rare? So how are we so certain it even exists at all? You say that the link is "firmly established" in Russian and Chinese literature, but I know of no such link. Again, if you have references, please! I'm not married to any of my ideas.
On the other hand, tooth decay certainly is not rare! And if you don't think tooth decay is a serious enough disease to warrant taking some calculated risks, consider that edentulism has been strongly associated with a decreased lifespan. This is not to mention the obvious decrease in quality of life - even with a good set of dentures. I would even argue that edentulism can precipitate depression - and this is *not* rare. I have already seen it firsthand many times in my very short clinical experience. Can you imagine living without teeth? Even the best dentures are, pretty obviously, dentures, and don't even come close to paralleling natural dentition in terms of function. What about living with severely painful or decayed teeth? I know it would affect me!
If the dental profession listened to all the anti-information, we would have *no* treatment options short of pulling teeth and fabricating dentures. Fluoride is bad. Dental amalgam is bad. Bis-GMA resins are worse. Cast metals are causing Lupus. Endodontic therapy causes NICO. If we do gold work (about the only totally inert material), it's not cost-effective enough.
So tell me what the ideal solution is, in your mind? We must take some (very well calculated, in my opinion) risks to make headway in *any* disease, and this includes dental disease.
I always appreciated a good exchange with you Larry, even if we seem to be of different minds much of the time (except for CBT, of course ;))
Best,
Matt
poster:mattdds
thread:263511
URL: http://www.dr-bob.org/babble/20030923/msgs/263760.html