26 l © 2025 American Dental Association
Section 1: Effectiveness and Benefits
Data from National Lithuanian Oral Health Survey
Similar findings supporting the benefits of community water fluoridation for adults include a 2021 study
of adults ages 34–74 in Lithuania where greater exposure to optimal fluoride in water corresponds
with lower caries experience.136
Data from US National Health and Nutrition Examination Surveys
A window into the positive impact of community water fluoridation in the United States can be
seen from research done in nationally representative samples of US adults. Differences in tooth
decay patterns between two cohorts of young adults highlight this: the first cohort grew up before
fluoridation was widely available and the second after fluoridation became more widespread.
Comparing data from two different US National Health and Nutrition Examination Surveys (NHANES),
NHANES I (1971–1974), and NHANES III (1988–1984), the results indicated that total tooth decay
declined among people aged 45 years and younger at the time of the survey. No decline was observed
in people then aged 46–65, the cohort that grew up during the late 1940s and early 1950s before
fluoridation was widely available. Lack of exposure to community water fluoridation was cited as the
major reason this older cohort did not show a decline in tooth decay.137
Root Surface Decay
An important issue for adults is the prevention of root surface decay.125,126 People in the United
States are living longer and retaining more of their natural teeth than ever before, in part due to
water fluoridation. Adults with gum recession are at risk for root surface decay because the root
surface, a much softer tooth surface than enamel, becomes exposed to decay-causing bacteria in
the mouth as gums recede.
While most studies related to the prevention of root surface decay focus on professional fluoride
treatments, such as fluoride varnish, there is evidence that demonstrates fluoridation has an impact
on root surface decay.138–140 For example, in Ontario, Canada, lifelong residents of the non-fluoridated
community of Woodstock had a 21% higher root surface decay experience than those living in the
naturally fluoridated (1.6 ppm) matched community of Stratford.139 Similarly, Iowa residents more
than 40 years of age living long-term in fluoridated communities had significantly less root decay
than lifelong residents of non-fluoridated communities (0.56 versus 1.11 surfaces).140
Fluoridation is unique in that it remains the one dental public health measure that reaches all members
of a community, including young, middle-aged, and older adults. It is a cost-effective approach for
achieving life-long caries prevention in a manner that addresses health equity.141
Section 1: Effectiveness and Benefits
Data from National Lithuanian Oral Health Survey
Similar findings supporting the benefits of community water fluoridation for adults include a 2021 study
of adults ages 34–74 in Lithuania where greater exposure to optimal fluoride in water corresponds
with lower caries experience.136
Data from US National Health and Nutrition Examination Surveys
A window into the positive impact of community water fluoridation in the United States can be
seen from research done in nationally representative samples of US adults. Differences in tooth
decay patterns between two cohorts of young adults highlight this: the first cohort grew up before
fluoridation was widely available and the second after fluoridation became more widespread.
Comparing data from two different US National Health and Nutrition Examination Surveys (NHANES),
NHANES I (1971–1974), and NHANES III (1988–1984), the results indicated that total tooth decay
declined among people aged 45 years and younger at the time of the survey. No decline was observed
in people then aged 46–65, the cohort that grew up during the late 1940s and early 1950s before
fluoridation was widely available. Lack of exposure to community water fluoridation was cited as the
major reason this older cohort did not show a decline in tooth decay.137
Root Surface Decay
An important issue for adults is the prevention of root surface decay.125,126 People in the United
States are living longer and retaining more of their natural teeth than ever before, in part due to
water fluoridation. Adults with gum recession are at risk for root surface decay because the root
surface, a much softer tooth surface than enamel, becomes exposed to decay-causing bacteria in
the mouth as gums recede.
While most studies related to the prevention of root surface decay focus on professional fluoride
treatments, such as fluoride varnish, there is evidence that demonstrates fluoridation has an impact
on root surface decay.138–140 For example, in Ontario, Canada, lifelong residents of the non-fluoridated
community of Woodstock had a 21% higher root surface decay experience than those living in the
naturally fluoridated (1.6 ppm) matched community of Stratford.139 Similarly, Iowa residents more
than 40 years of age living long-term in fluoridated communities had significantly less root decay
than lifelong residents of non-fluoridated communities (0.56 versus 1.11 surfaces).140
Fluoridation is unique in that it remains the one dental public health measure that reaches all members
of a community, including young, middle-aged, and older adults. It is a cost-effective approach for
achieving life-long caries prevention in a manner that addresses health equity.141
