Below is Paul Melters’ response to Johnny Johnson’s comment
concerning the 5 studies listed by
Louise Mantella in Comment 47741 - Ken Perrott blog.

November 28, 2013

In COMMENT 47834, Johnny Johnson writes:

JOHNSON:“The references you make regarding fluorosis and caries are not from studies done in the United States, nor Canada. Perhaps your position would be better supported if you provided peer reviewed literature from the US or Canada that’s more applicable to the United States.”

PM Response: The two most important and most recent references were from studies done in
Mexico. Last time I checked, Mexico was right next to the USA. I understand that there is also a very large hispanic population in the US (53 million).

JOHNSON:“As Billy points out, studies must pass the critical review process that credible scientific journals require. That includes sample size, control of confounding factors (to the best that they can be), and a representative sampling of the population.”

PM Response: Both studies were published in peer-reviewed, credible scientific journals.

1) Azpeitia-Valadez et al: (2008)

Sample: 6 to 15 years old children. 456 children was evaluated. 270 children presented fluorosis (59.2 %). Sample size, representation of population, and method of investigation are discussed.

2) Pontigo-Loyola et al (2007)

Sample size - Pontigo-Loyola: 12 to 15 year old children. A total of 1,538 adolescents
(representing 86.9 percent of the population) were included.

Confounding factors: As already mentioned in the post to Billy Budd, any “control of confounding factors” here really is irrelevant. Have a look at the Pontigo-Loyola paper and tell me what variables should have been controlled for, and weren’t. And, as you’re stressing the importance of controlling factors - please answer the question at the bottom of this post. You’ve been avoiding it for

JOHNSON: “Taking literature that meets one’s own position is easy to do. I am just as guilty of this bias as the next person. However, my bias is based on the literature that has appeared in refereed peer reviewed scientific journals worldwide. This literature is weighed by the experts in this particular field and debated in expert panels like the 2006 NRC Review of EPA standards, and the U.S. Community Preventive Services Task Force. These folks are tasked with reviewing volumes of literature and arriving at a consensus opinion. It is those experts that I rely on, not a handful of studies done somewhere, anywhere, that happens to support my position.”

PM Response: See above. These papers are recent publication (2007, 2008), published AFTER the 2006 NRC review.

JOHNSON: “The science is crystal clear. Community water fluoridation is effective and safe. That’s the consensus opinion of our experts at this time. And it has been that same consensus for the past 68 years. When, and if that were to ever change, Ken would be one of the first to broadcast it, right after the CDC and other credible scientific groups have yelled it from the highest mountain.”

PM Response: The science is NOT crystal clear. If it were, why have you NOT been able to provide ONE scientific study showing this - as has been asked from you now many, many times? Where I live, caries DECREASED once fluoridation stopped.

Maupomé G, Clark DC, Levy SM, Berkowitz J. Patterns of dental caries following the cessation of water fluoridation. Community Dent Oral Epidemiol. 2001 Feb;29(1):37-47.

I will ask once again - please provide ONE study capable of demonstrating this “effective and safe” effect of CWF that has accounted for established confounding factors such as race, gender, age, total intake, tooth eruption, brushing and other oral hygiene factors, SES.


Paul Melters