© 2025 American Dental Association l 17
Fluoridation Facts
Summary of Systematic Reviews (Parnell et al., 2009)
A summary of systematic reviews by the Oral Health Services Research Centre at the University Dental
School in Cork, Ireland, published in 2009,98 reviewed results from three systematic reviews, all of which
were published between 2000 and 2007. The summary of results concluded that the best available
scientific evidence demonstrated that water fluoridation was an effective community-based method
to prevent tooth decay, especially for the disadvantaged who bear the greatest burden of disease.98
Systematic Review and Meta-Analysis (Griffin et al., 2007)
A meta-analysis (a type of systematic review that seeks to determine a statistical estimate of an overall
benefit based on the results of the collection of studies included in the review) published in 2007 in
the Journal of Dental Research demonstrated the effectiveness of water fluoridation for preventing
tooth decay in adults.63 Twenty studies representing more than 13,500 participants were included
in the analysis. Of the 20 studies, nine examined the effectiveness of water fluoridation. A review
of these studies found that fluoridation prevents approximately 27% of tooth decay in adults.63
First Fifty Years Review—International (Murray, 1993)
In 1993, the results of 113 studies in 23 countries (more than half the studies were from the United
States) were compiled and analyzed.99 That review provided effectiveness data for 66 studies of primary
teeth and 86 studies of permanent teeth. The analysis of the studies demonstrated a 40–49% overall
decay reduction for primary teeth and a 50–59% overall decay reduction for permanent teeth for
those living in fluoridated communities.99
First 50 Years Review—United States (Ripa, 1993)
A comprehensive analysis of the first 50 years of community water fluoridation in the United States
concluded that “Community water fluoridation is one of the most successful public health disease
prevention programs ever initiated.”100 While noting that the difference in tooth decay between
optimally fluoridated communities and fluoride-deficient communities was smaller than in the early
days of fluoridation, largely due to additional sources of fluoride, the difference was still significant
and the benefits for adults should be emphasized. The report ended by noting that water fluoridation
is a near-ideal public health measure whose benefits can transcend racial, ethnic, socioeconomic, and
regional differences.100
The systematic reviews noted here provide scientific evidence that, for more than 80 years,
fluoridation has been effective in helping to prevent tooth decay.
Fluoridation Facts
Summary of Systematic Reviews (Parnell et al., 2009)
A summary of systematic reviews by the Oral Health Services Research Centre at the University Dental
School in Cork, Ireland, published in 2009,98 reviewed results from three systematic reviews, all of which
were published between 2000 and 2007. The summary of results concluded that the best available
scientific evidence demonstrated that water fluoridation was an effective community-based method
to prevent tooth decay, especially for the disadvantaged who bear the greatest burden of disease.98
Systematic Review and Meta-Analysis (Griffin et al., 2007)
A meta-analysis (a type of systematic review that seeks to determine a statistical estimate of an overall
benefit based on the results of the collection of studies included in the review) published in 2007 in
the Journal of Dental Research demonstrated the effectiveness of water fluoridation for preventing
tooth decay in adults.63 Twenty studies representing more than 13,500 participants were included
in the analysis. Of the 20 studies, nine examined the effectiveness of water fluoridation. A review
of these studies found that fluoridation prevents approximately 27% of tooth decay in adults.63
First Fifty Years Review—International (Murray, 1993)
In 1993, the results of 113 studies in 23 countries (more than half the studies were from the United
States) were compiled and analyzed.99 That review provided effectiveness data for 66 studies of primary
teeth and 86 studies of permanent teeth. The analysis of the studies demonstrated a 40–49% overall
decay reduction for primary teeth and a 50–59% overall decay reduction for permanent teeth for
those living in fluoridated communities.99
First 50 Years Review—United States (Ripa, 1993)
A comprehensive analysis of the first 50 years of community water fluoridation in the United States
concluded that “Community water fluoridation is one of the most successful public health disease
prevention programs ever initiated.”100 While noting that the difference in tooth decay between
optimally fluoridated communities and fluoride-deficient communities was smaller than in the early
days of fluoridation, largely due to additional sources of fluoride, the difference was still significant
and the benefits for adults should be emphasized. The report ended by noting that water fluoridation
is a near-ideal public health measure whose benefits can transcend racial, ethnic, socioeconomic, and
regional differences.100
The systematic reviews noted here provide scientific evidence that, for more than 80 years,
fluoridation has been effective in helping to prevent tooth decay.
