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Volume1 Issue1
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ews and
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The impact of removing fluoridation frommunicipal water supplies inCanada:
ataleoftwocities
Why do you think it’s important to
conductthisstudy?
Researchondrink-
ingwater fluoridationasapublichealth
intervention, on balance, supports the
benefits of fluoridation for the preven-
tion of tooth decay in populations. But
things can changeover time. So it’s im-
portant that we keep the literature up
todate.
Drinking water fluoridation, because it
affects the whole population, is poten-
tially a very powerful intervention and
that’s a big part of its appeal, or lack of
appeal, depending onwhat side of the
debate you’reon. If there’sabenefit that
we’renow losing, weneed to know this
to inform future decision making. I’m
not saying we’re necessarily going to
seeabenefit, but if it’s therewewant to
document it.
Why does the evidence on drinking
water fluoridation need an update?
Arguably, most of the research is from
cases of fluoridation initiation—when
communities start fluoridating their
water— and its impact on oral health.
There are far fewer studies on the dis-
continuation of fluoridation. Also, it’s
important to consider the time and
place of the studies. Unlike in the 1960s
and70s,wenowhaveagreater number
of sourcesoffluoride thatwe’reexposed
to. And finally, the oral healthprofile of
the population has changed. When
fluoridationwas first implementedback
in the1940s and1950s toothdecaywas
almost universal among thechildpopu-
lation and that’s not the case anymore.
Tooth decay is still common, but not
nearly as common as it was backwhen
fluoridation started.
Who will your study be looking at?
Our target population is children in
grade 2. We picked this age group—
around 7 years old—because, on aver-
age, children of that age have started
to develop some of their adult teeth
so it will allow us to examine both
baby teeth and adult teeth in one age
group. We’re doing oral health assess-
ments, a visual-tactile exam conducted
by registered dental hygienists that will
take about 10 minutes per child. There
is also a questionnaire for the parents
to complete. The questionnaire is really
designed to tap into other determin-
ants of oral health—aside fromdrinking
water fluoridation— that we’ll take into
account inour analyses.
What factors are being evaluated in
the questionnaire for parents?
Diet,
oral healthbehaviours likebrushingand
flossing, visits to the dentist, whether
they have dental insurance and what
type, the primary source of drinking
water, how long they’ve lived in their
currenthome. And if a familyhasmoved
during the child’s life, what other com-
munities have they lived in?Wewill also
ask about sociodemographic informa-
tion, like household education level,
whether the home is owned or rent-
ed, median income of the census area
where this child’s school is located, and
ethnocultural backgroundof the family.
Howmanychildrenwillbeexamined?
For each city, we hope to examine sev-
eral thousand from about 150 schools,
so it’s quite a big sample size. We’re in
Calgary and Edmonton schools for this
entireacademicyear.
What do you expect your study
will find?
I honestly don’t know. I’m of
course very, very curious. On one hand,
I feel that theexisting research literature,
on balance, supports a beneficial effect
of drinking water fluoridation on oral
health. And so from that point of view,
wemight expect to seeadecline inoral
health in Calgary, reflecting the remov-
al of fluoride from thewater. But on the
other hand, times have changed, and
we can’t assume that findings frompre-
vious studies will show up in this time
andplace.
Do you think your work will influ-
ence the debates over fluoridat-
ing drinking water?
Evidence is only
one piece of why some people sup-
port or don’t support drinking water
fluoridation. Our study is only speak-
ing to the evidence aspect. That said,
I don’t think it’s out of the question that
the Calgary city council will look careful-
ly at our results. I’m not sure what they
would dowith it, but I do think it would
bean importantpieceof thediscussion.
a
This interviewhasbeencondensedandedited.
Questions about the effectiveness ofmunicipal water fluoridation in
preventing tooth decay have polarized scores of communities across
Canada. Dr. LindsayMcLaren, a researcher from the University of
Calgary, alongwith a teamof experts inpublic health anddentistry,
is aiming to enrich the debate by examining whether Calgary’s city
council decision to stop fluoridating its water in 2011 has affected
the oral health of children living in that city. She talked to CDA about her research
project thatwill compare levelsof toothdecay inyoungCalgarians to children living in
Edmonton—a citywhere thedrinkingwater supply isfluoridated.
Toothdecay is still common, but not nearlyas
commonas itwas backwhenfluoridation started.
