Fluoridation in the UK

[Ivor the Engineer]

Why wasn't that said in the actual study?

The actual study:

Conclusions
This review presents a summary of the best available and most reliable evidence on the safety and efficacy of water fluoridation.

Given the level of interest surrounding the issue of public water fluoridation, it is surprising to find that little high quality research has been undertaken. As such, this review should provide both researchers and commissioners of research with an overview of the methodological limitations of previous research conducted in this area.

The evidence of a benefit of a reduction in caries should be considered together with the increased prevalence of dental fluorosis. The research evidence is of insufficient quality to allow confident statements about other potential harms or whether there is an impact on social inequalities. This evidence on benefits and harms needs to be considered along with the ethical, environmental, ecological, costs and legal issues that surround any decisions about water fluoridation. All of these issues fell outside the scope of this review.

Any future research into the safety and efficacy of water fluoridation should be carried out with appropriate methodology to improve the quality of the existing evidence base.

Also, what makes this almost decade old study so authoritative in your eyes?

It was a review of studies performed world-wide. I admit I'm going out on a limb believing that the authors were not idiots. Perhaps one day I'll organise my own DBPCT.

 

[Tomblvd]

The actual study:





It was a review of studies performed world-wide. I admit I'm going out on a limb believing that the authors were not idiots. Perhaps one day I'll organise my own DBPCT.

Well, here's a more recent (2007) meta-type study from Australia:

http://www.nhmrc.gov.au/publications/synopses/eh41syn.htm

Research question: Is intentional water fluoridation more efficacious than no water fluoridation in the prevention of dental caries?

The existing body of evidence strongly suggests that water fluoridation is beneficial at reducing dental caries. After adjustment for potential confounding variables, McDonagh et al (2000a) showed
in their systematic review that the introduction of water fluoridation into an area significantly increased the proportion of caries-free children, and decreased mean dmft/DMFT scores compared with areas which were non-fluoridated over the same time period. The findings of McDonagh et al (2000a) also suggest that cessation of fluoridation resulting in a narrowing of the difference in caries prevalence between the fluoridated and non-fluoridated populations. Only one additional relevant original study was identified in the current review and this did not change the conclusion of the existing systematic review.

Research question: Does intentional water fluoridation result in dental fluorosis over and above no intentional water fluoridation?

There is consistent Level III/IV evidence from existing systematic reviews that water fluoridation results in the development of dental fluorosis. However, the majority of dental fluorosis is mild and is not considered to be of ‘aesthetic concern’. The number needed to harm (NNH) with water fluoridation at an optimal level compared with no fluoridation to get one additional person with ‘any fluorosis’ is approximately 6. The corresponding NNH to get one additional person with ‘fluorosis of aesthetic concern’ is approximately 22. Meta-analysis of additional original studies provides results consistent with those seen in the existing systematic reviews.

 

[Ivor the Engineer]

Which is what the York review found. A lot of not very good evidence, which depending on your subjective opinion of whether fewer fillings or less dental fluorosis is more desirable, either does or does not support the fluoridation of tap water.

If it was up to me, I'd want to be much more certain than the current standard of evidence allows us to be about the scale of the potential benefits and harms before recommending mass-medication. But it isn't up to me, so it doesn't matter what I think.

 

[Tomblvd]

Which is what the York review found.

Really?

The existing body of evidence strongly suggests that water fluoridation is beneficial at reducing dental caries.

There is consistent Level III/IV evidence from existing systematic reviews that water fluoridation results in the development of dental fluorosis. However, the majority of dental fluorosis is mild and is not considered to be of ‘aesthetic concern’.

Given that, I fail to see any reason to question fluoridation. I can't recall a study that ever said "no further study on this topic is necessary". It is the nature of researchers to, well, research.

You have given the York researchers (well, at least the one who wrote the unsigned "correction") almost mythical status. I'm not sure why, other that it gives you a very slim thread to hang on to. However, speaking as an "expert" (one of the very few times I get to do this on the internet), I can honestly say that I have never, ever seen a severe case of dental fluorosis, and very seldom have I ever had to repair a cosmetic fluorosis problem.

The data is out there, fluoride is effective and safe.

 

[Ivor the Engineer]

<snip>

Given that, I fail to see any reason to question fluoridation.

<snip>

So why do you care what I or anyone else thinks of the evidence?

 

[Tomblvd]

So why do you care what I or anyone else thinks of the evidence?

Obviously for the benefit of anybody reading this thread. I realize by your tenacious clinging to that "clarification" of that single study that you don't like fluoridation (yes, I'm putting words in your mouth but really, why play games?), and nothing in the recent literature will change your mind. But there are people who will read this, and I feel it is important to hear the reality concerning fluoridation.

Put very simply, and addressing your concerns, YES it is effective in preventing dental caries primarily in pediatric cases, and NO it does not cause, per se, moderate to severe fluorosis.

It really is that simple.

 

[Ivor the Engineer]

Obviously for the benefit of anybody reading this thread. I realize by your tenacious clinging to that "clarification" of that single study that you don't like fluoridation (yes, I'm putting words in your mouth but really, why play games?), and nothing in the recent literature will change your mind. But there are people who will read this, and I feel it is important to hear the reality concerning fluoridation.

Put very simply, and addressing your concerns, YES it is effective in preventing dental caries primarily in pediatric cases, and NO it does not cause, per se, moderate to severe fluorosis.

It really is that simple.

1) It was not a "single study" it was a review of the studies performed world-wide.

2) The evidence suggests the NNT for a reduction in dental caries is 6, and the NNH for mild fluorosis is 6, or 22 for "aesthetically concerning" fluorosis.

3) The evidence for other possible harms is of insufficient quality to draw any reliable conclusions.

What I don't like is mass medication based on crappy evidence. I am quite aware that medical professionals typically settle for a much lower standard of evidence than I do in my professional activities for a variety of reasons, some of which I think are valid, others less so.

 

[Tomblvd]

1) It was not a "single study" it was a review of the studies performed world-wide.

Your nit is well picked.

2) The evidence suggests the NNT for a reduction in dental caries is 6, and the NNH for mild fluorosis is 6, or 22 for "aesthetically concerning" fluorosis.

So studies showed fluoride is effective and the risk of "aesthetically concerning" is low. Your point?

3) The evidence for other possible harms is of insufficient quality to draw any reliable conclusions.

Given the tremendously long time frame, the inconsistent levels of fluoridated water, and the extremely litigous nature of society, I'm more than convinced of its safety.

If you want me to prove it is NOT harmful, you'll have a long wait, as, you undoubtely already know, it is impossible.

What I don't like is mass medication based on crappy evidence. I am quite aware that medical professionals typically settle for a much lower standard of evidence than I do in my professional activities for a variety of reasons, some of which I think are valid, others less so.

First of all, it is silly in the extreme to call fluoridation "medication" simply due to the fact that it is naturally occurring in many areas of the world. Since in the US there are many areas that have fluoride levels above the recommended limit, do you suggest the local water supplies completely remove all natual fluoride from the water? Do you see how silly that is?

Second, considering fluoridation is about as universally accepted as any health measure can be (over 130 countries provide fluoride in some way), that's an awful lot of stupid, lazy or compromised doctors and scientists. I'm glad you are so professionally pure, I guess you've exposed the rest of us.

 

[Ivor the Engineer]

<snip>

So studies showed fluoride is effective and the risk of "aesthetically concerning" is low. Your point?

An NNH of 22 (4 to 5%) is NOT low.

Given the tremendously long time frame, the inconsistent levels of fluoridated water, and the extremely litigous nature of society, I'm more than convinced of its safety.

Good for you.

If you want me to prove it is NOT harmful, you'll have a long wait, as, you undoubtely already know, it is impossible.

No, I want to see large, good quality studies, not collections of crappy ones.

First of all, it is silly in the extreme to call fluoridation "medication" simply due to the fact that it is naturally occurring in many areas of the world. Since in the US there are many areas that have fluoride levels above the recommended limit, do you suggest the local water supplies completely remove all natual fluoride from the water?

If the levels cause aesthetically concerning dental fluorosis or more serious health effects, then yes.

Do you see how silly that is?

Not really.

Second, considering fluoridation is about as universally accepted as any health measure can be (over 130 countries provide fluoride in some way), that's an awful lot of stupid, lazy or compromised doctors and scientists. I'm glad you are so professionally pure, I guess you've exposed the rest of us.

I bet you are when you get on a plane. Oh what fun the world would be if engineers used 95% (or even 99.9%) CI's for their designs...