14 l © 2025 American Dental Association
Section 1: Effectiveness and Benefits
6. Is there a difference in effectiveness between naturally occurring
fluoridated water (at optimal fluoride levels) and water that has
fluoride added to reach the optimal level?
Answer
No. The dental benefits of optimally fluoridated water occur regardless of the fluoride’s source.
Fact
Fluoride is present in water as “ions” or electrically charged atoms.92 These ions are the same whether
acquired by water as it seeps through rocks and sand or added to the water supply under carefully
controlled conditions.
The major features of the human fluoride metabolism are not affected by which of the three fluoride
additives is used in community water fluoridation, nor are they affected by whether the fluoride is
present naturally or added to drinking water.93 In simpler terms, there is no difference chemically
between natural and adjusted fluoridation.
When fluoride is added under controlled conditions to fluoride-deficient water, the dental benefits are
the same as those obtained from naturally fluoridated water. Fluoridation is merely an increase of the
level of the naturally occurring fluoride present in all drinking water sources to the level recommended
for optimal dental health.
For example, a fluoridation study22 conducted in the Ontario, Canada, communities of Brantford
(optimally fluoridated by adjustment), Stratford (optimally fluoridated naturally), and Sarnia (fluoride-
deficient) revealed much lower decay rates in both Brantford and Stratford as compared with non-
fluoridated Sarnia. There was no observable difference in the decay-reducing effect between the
naturally occurring fluoride and adjusted fluoride concentration water supplies.22
Some individuals use the term “artificial fluoridation” to imply that the process of water fluoridation is
unnatural and that it delivers a foreign substance into a water supply when, in fact, all water sources
contain some fluoride. The fluoride ion released in water is the same regardless of the source92 and
is metabolized (processed) by the body in the same way no matter what the source is.93 Community
water fluoridation is a natural way to improve oral health.
Fluoridation is merely an adjustment of the level of the naturally occurring
fluoride present in all drinking water sources to the level recommended for
optimal dental health.
Section 1: Effectiveness and Benefits
6. Is there a difference in effectiveness between naturally occurring
fluoridated water (at optimal fluoride levels) and water that has
fluoride added to reach the optimal level?
Answer
No. The dental benefits of optimally fluoridated water occur regardless of the fluoride’s source.
Fact
Fluoride is present in water as “ions” or electrically charged atoms.92 These ions are the same whether
acquired by water as it seeps through rocks and sand or added to the water supply under carefully
controlled conditions.
The major features of the human fluoride metabolism are not affected by which of the three fluoride
additives is used in community water fluoridation, nor are they affected by whether the fluoride is
present naturally or added to drinking water.93 In simpler terms, there is no difference chemically
between natural and adjusted fluoridation.
When fluoride is added under controlled conditions to fluoride-deficient water, the dental benefits are
the same as those obtained from naturally fluoridated water. Fluoridation is merely an increase of the
level of the naturally occurring fluoride present in all drinking water sources to the level recommended
for optimal dental health.
For example, a fluoridation study22 conducted in the Ontario, Canada, communities of Brantford
(optimally fluoridated by adjustment), Stratford (optimally fluoridated naturally), and Sarnia (fluoride-
deficient) revealed much lower decay rates in both Brantford and Stratford as compared with non-
fluoridated Sarnia. There was no observable difference in the decay-reducing effect between the
naturally occurring fluoride and adjusted fluoride concentration water supplies.22
Some individuals use the term “artificial fluoridation” to imply that the process of water fluoridation is
unnatural and that it delivers a foreign substance into a water supply when, in fact, all water sources
contain some fluoride. The fluoride ion released in water is the same regardless of the source92 and
is metabolized (processed) by the body in the same way no matter what the source is.93 Community
water fluoridation is a natural way to improve oral health.
Fluoridation is merely an adjustment of the level of the naturally occurring
fluoride present in all drinking water sources to the level recommended for
optimal dental health.
