A news piece by KWCH 12 in Wichita Kansas about a local community voting on whether to cease water fluoridation quotes local dentist, Doctor Allison Lesko, as saying:

Depending on which grade level they were, anywhere from 90 to 200 percent increase in cavities within that five years. So this is something that we are going to see and we obviously don't want to see that.

The quote appears to be referring to a previous community (or communities) which ceased water fluoridation and had a 90-200% increase in cavities.

My question: Is there a documented case of a community observing a 90-200% increase in cavities after the cessation of artificial water fluoridation?


I have only found studies comparing two cities (one with, one without artificial fluoridation), or very large-scale (i.e. national) scale statistics which show an overall decrease in cavities over time, but which is too general to account for the cessation of fluoridation in individual communities.

I am looking specifically for a case study where artificial water fluoridation was ceased, and cavities increased over the following 5 years, as claimed in the quote.

  • Well, there are lots of Canadian cities to pick: o.canada.com/health/hows-that-fluoride-free-water-treating-you, going back to 2001, if you can find stats on cavities. Nov 3, 2014 at 15:35
  • @Sklivvz: I see the reason for your new tag. I think a study from any country would count toward an answer, not just from the US.
    – Flimzy
    Nov 3, 2014 at 20:28
  • I assume this claim is about a specific case, not a general rule, in which case it applies (i guess).
    – Sklivvz
    Nov 3, 2014 at 21:37
  • @Sklivvz: But I don't know where that specific case happened, it could well have been outside of the USA.
    – Flimzy
    Nov 3, 2014 at 21:41

1 Answer 1


Cannot confirm the above, but there are plenty of examples where cavities rates went DOWN when fluoridation ended, for example:

Caries frequency before and after discontinuation of water fluoridation in Kuopio, Finland

In spite of discontinued water fluoridation, no indication of an increasing trend of caries could be found in Kuopio. The mean numbers of fluoride varnish and sealant applications decreased sharply in both towns between 1992 and 1995. In spite of that caries declined.

PMID: 9758426

Patterns of dental caries following the cessation of water fluoridation” [Canada]

The prevalence of caries (assessed in 5,927 children, grades 2, 3, 8, 9) decreased over time in the fluoridation-ended community while remaining unchanged in the fluoridated community.

PMID: 11153562

Caries prevalence after cessation of water fluoridation La Salud, Cuba

In the past, caries has usually increased after cessation of water fluoridation. More recently an opposite trend could be observed: following the cessation of drinking water fluoridation, in contrast to an expected rise in caries prevalence, DMFT and DMFS values remained at a low level for 6-9-year-olds and to decrease for 10/11-year-olds. In the 12/13-year-olds, there was a significant decrease.

PMID: 10601780

Decline of caries prevalence after the cessation of water fluoridation in the former East Germany

In contrast to the anticipated increase in dental caries following the cessation of water fluoridation in the cities Chemnitz and Plauen, a significant fall in caries prevalence was observed. This corresponded to the national caries decline and appears to be a new population-wide phenomenon. There is still no explanation for the pattern.

PMID: 11014515

…dental caries in 12-year-old children residing in cities with and without fluoridated water supply… [São Paulo, Brazil]

There was no statistically significant difference between DMFT in municipalities of the same size, regardless of the presence or absence of fluoride in the water supply… Prevalence of caries in the region was ‘high’, with a DMFT of 4.82, thus failing to reach the goals set for the year 2000.

PMID: 12244360

The fluoride content of drinking water and caries experience in 15-19 year old school children in Iba-dan, Nigeria

955 students aged 15-19 years randomly selected from eleven secondary schools in Ibadan metropolis were examined for dental caries. The fluoride level of the different water sources was between 0.02 and 0.03 ppm. [only] Forty-four (4.6%) of the children had dental caries. In conclusion, both the fluoride level and caries prevalence were low.

PMID: 18756850

Prevalence and severity of dental caries in adolescents… [Mexico]

In an analysis of caries severity (DMFT > or = 4), both adolescents with very mild/mild and moder-ate/severe dental fluorosis have higher caries severity. Fluoride exposure (measured through fluorosis presence) does not appear to be reducing the caries prevalence (DMFT > 0) or caries severity (DMFT > or = 4) in these high-altitude communities.

PMID: 17436973

[The effects of a break in water fluoridation [11 months] on the development of dental caries and fluorosis” Durham, North Carolina

It was concluded that while the break had little effect on caries, dental fluorosis is sensitive to even small changes in fluoride exposure from drinking water, and this sensitivity is greater at 1 to 3 years of age than at 4 or 5 years.

PMID: 10728978

  • 3
    Any control about other source of fluoride in those studies? That is, if water fluoridation is ended but people still get enough fluoride from toothpaste or other sources then it is not that surprising not to see an effect.
    – nico
    Nov 3, 2014 at 20:20
  • 6
    @nico Especially if people knew the water fluoridation was ending, and specifically took steps to ensure they had enough fluoride from other sources (or were simply more dental-hygiene aware as a result of it).
    – Is Begot
    Nov 3, 2014 at 20:55
  • 1
    I have to downvote this answer, as it doesn't address the question (which it admits in the first sentence). It's interesting information, but not relevant to directly answering this question. While this information may be beneficial in addressing the general implied claim that water fluoridation will always result in a reduction of cavities, the specific claim is looking for a single case study of a city with a specific negative result after the removal of fluoride.
    – Flimzy
    Nov 4, 2014 at 0:24

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