Frequently Asked Questions

 Below is a list of commonly asked questions and some common misinformation about fluoridation. If you do not see the information you are looking for, please feel free to get in touch with us anytime at [email protected]. The American Dental Association also provides an in depth look at fluoride in their “Fluoride Facts" handbook (PDF).

Interested in doing your own research? Here’s a list of peer-reviewed studies, reports, and reviews of studies. This list demonstrates the decades of research on fluoridation.

Fluoride Studies


What is fluoride, and how does it benefit dental health?

Fluoride is a mineral that exists naturally in rocks, soil, and nearly all water supplies. According to the Centers for Disease Control and Prevention (CDC), at the proper level in drinking water, fluoride prevents tooth decay. This optimal level is reached when a public water system adjusts — by increasing or lowering — the level of fluoride.

Why is Oregon experiencing a dental health crisis?

Oregon’s low water fluoridation levels and high rates of underinsured or uninsured individuals are contributing to an oral health crisis. Portland is the largest U.S. city that has not adopted water fluoridation, and Oregon ranks 48th among all states in access to fluoridated water. Our uninsured rate is higher than 40 other states. According to the Oregon Department of Human Services, children are paying the biggest price. The 2007 Oregon Smile Survey reveals that Oregon children suffer higher rates of untreated tooth decay than those in neighboring states. The same survey shows untreated tooth decay increased 49 percent in Oregon from 2002 to 2007 and that more than 35 percent of Oregon children have untreated tooth decay — compared with 15 percent in Washington. Nationally, Oregon ranks near the bottom for childhood oral health.  Similarly, the Portland metro area ranks below neighboring cities.  The tri-county area has twice the rate of untreated tooth decay of Vancouver, just across the river, and 40% more decay than Seattle area.  Both those communities have water fluoridation.

Can water fluoridation really help prevent tooth decay?

Yes. Numerous studies prove that water fluoridation is one of the most effective ways to prevent tooth decay in a community. According to the American Dental Association, water fluoridation can reduce cavities by at least 25%, and can reduce the need for more serious dental surgeries by even more.

Fluoridated drinking water guards growing teeth from decay and continuously protects everyone’s teeth over a lifetime.  Fluoridation is especially beneficial to the elderly to protect them from losing teeth later in life.

American Dental Association, “Fluoridation Facts," Chicago, Illinois, 2005.

How does oral health affect overall health?

Research shows that the health of the mouth affects total health. According to the surgeon general, recent research links chronic oral infections with heart and lung diseases, stroke, and premature births. Untreated tooth decay can cause tooth loss, oral diseases, abscesses, bone loss, infection in the bloodstream, speech problems, and low self-esteem. Tooth decay is the most common childhood disease and is a leading cause of school absenteeism.  It affects five times more children than asthma. Left untreated, tooth decay can impair a child’s ability to eat, speak, learn, and play. It can also prevent educational success and future employment opportunities.

Healthy People: 2010. Html version hosted on website.
S. Blumenshine et al., “Children’s School Performance: Impact of General and Oral Health," Journal of Public Health Dentistry 68 (2008): 82–87.

Is tooth decay preventable and treatable?

Yes. Education, dental exams, and fluoride prevent and treat tooth decay and cavities. Water fluoridation is an important part of that strategy. Even with widespread access to fluoride from other sources, such as fluoride toothpaste and tablets, studies prove water fluoridation reduces tooth decay by at least 25 percent.

American Dental Association. Fluoride & Fluoridation.

Aren’t fluoride toothpaste and tablets enough?

No. If tablets and brushing alone were enough, Oregon would not be experiencing levels of tooth decay far in excess of our fluoridated neighbors. Brushing your teeth and drinking fluoridated water go hand in hand to promote healthy teeth.  Brushing your teeth with fluoridated toothpaste reduces cavities by about 25%, and drinking fluoridated water reduces cavities by another 30% on top of brushing.  Fluoride works best when we both ingest a low level of fluoride throughout the day by drinking fluoridated water, and we also apply a higher concentration directly to the teeth.  Water fluoridation provides the foundation of dental health.

Fluoride tablets are not as effective as water fluoridation and a lot more costly.  With fluoride tablets, it can be difficult to get kids to take the tablets on a regular basis, and in addition there is a potential for kids to take too many tablets.  Water fluoridation is therefore the most effective, safest and most affordable option.

American Dental Association, “Fluoridation Facts," Chicago, Illinois, 2005.

Is fluoride unsafe for some people to ingest?

No. According to thousands of peer-reviewed studies, fluoride produces no negative health effects at the level used to fluoridate drinking water. It is also not deemed an allergen, according to the American Academy of Allergy, Asthma, and Immunology.

Fluoride is a natural mineral and already exists in many sources of drinking water in the U.S. It is harmful to humans only in very high concentrations. The U.S. Department of Health and Human Services (HHS) identifies the optimal level of fluoride in public water systems as 0.7 milligrams per liter (mg/L) of water.

What is dental fluorosis?

Dental fluorosis found in the U.S. consists of barely noticeable white dots or streaks on the teeth.  It is determined that it has no negative health effects, and it likely associated with stronger teeth, that are more resistant to decay.  In rare cases, children under 4 years of age may develop a condition called severe dental fluorosis from ingesting high amounts of fluoride.  Most fluorosis is caused from kids swallowing their toothpaste.  The National Research Council has said that there is only a slight increase in mild fluorosis from drinking fluoridated water and the rate of severe fluorosis is essentially zero with optimally-fluoridated water.

What is the history of water fluoridation?

The benefits of water fluoridation go back more than 65 years. In 1945, Grand Rapids, Michigan, added fluoride to its municipal water system. Within a brief period, according to the National Academy of Sciences’ National Research Council, tooth decay in Grand Rapids dramatically dropped. Since then, thousands of studies have proved the effectiveness of community water fluoridation in reducing tooth decay.

Today, according to the American Dental Association, evidence shows water fluoridation reduces tooth decay in communities by at least 25%. Two studies released in 2010 strengthened the substantial evidence that fluoridated water prevents cavities.

Among numerous other organizations, the Centers for Disease Control and Prevention (CDC) recommends fluoridating public water supplies.

In 1999, the CDC recognized community water fluoridation as one of the 10 great public health achievements of the 20th century.

Opponents of water fluoridation have claimed that fluoridation was started in Nazi ghettos or concentration camps to control and pacify the Jews. This story has been tested by and deemed entirely false:

How does Oregon compare with other states in water fluoridation?

Oregon ranks 48th in water fluoridation among all states. And Portland is the largest metropolitan areas in the U.S. that has not adopted water fluoridation. Among Oregon cities that fluoridate water are Beaverton, Forest Grove, and Salem. In total, about one-fifth — more than 760,000 — of Oregon residents receive fluoridated public water. According to the American Dental Association, roughly 72 percent of Americans are connected to a fluoridated water system.

American Dental Association, Fluoridation Facts, Chicago, Illinois, 2005.

How much will it cost Portland residents to fluoridate the city’s public water?

Fluoridating Portland’s public water system is estimated to cost Portland residents about 61 cents per person, per year. Residents will also pay a onetime setup fee of about $5 per person.

What is the economic impact of fluoridating Portland’s drinking water?

Fluoridation has been shown to dramatically reduce dental costs, paying for itself many times over.  Three recent studies have shown that fluoridation cuts Medicaid dental costs in half, so we could cover twice as many people with the same money when water fluoridation is implemented.  The Centers for Disease Control estimated that about $38 is saved for every $1 invested in fluoridation.  Given these estimates, it is expected that the Portland area would save at least $20 million per year in dental costs, and about $5 million per year would be saved in Medicaid costs (i.e. taxpayer dollars).

American Dental Association, Fluoridation Facts, Chicago, Illinois, 2005.

Who backs water fluoridation in Portland?

More than 80 organizations have endorsed Portland’s proposal to fluoridate the water. These include social justice non-profits, research institutions, businesses and health systems.

To see the complete list visit: supporters.htm

Getting to the Truth

Is water fluoridation okay for small children?

The Truth: Getting enough fluoride in childhood will determine the strength of our teeth over our entire lifetime.

The Facts:

  • According to the American Academy of Pediatrics optimal exposure to fluoride is important to infants and children.  The use of fluoride for the prevention and control of cavities is documented to be both safe and effective.
  • All the major health and science organizations strongly disagree with opponents’ “toxic" claim.  In fact, the American Academy of Family Physicians recommends that parents consider using dietary fluoride supplements for children at risk of tooth decay from ages 6 months through age 16 if their water isn’t fluoridated.
  • Children who drink fluoridated water as their teeth grow will have stronger, more decay resistant teeth over their lifetime.  A 2010 study confirmed that the fluoridated water consumed as a young child makes the loss of teeth (due to decay) less likely 40 or 50 years later when that child is a middle-aged adult.

Does Fluoride belong in drinking water?

The Truth: yes, fluoride occurs naturally in water, though usually not at the optimal level to protect teeth. Fluoride is naturally occurring in Bull Run at 0.1ppm but needs to be at 0.7ppm for optimal health benefit.

The Facts:

  • Fluoride is already there.  Fluoride exists naturally in virtually all water supplies and even in various brands of bottled water.  To avoid ingesting fluoride completely, one would no longer be able to drink water, tea, beer or grape juice — or eat shellfish, meat, cheese or other foods that contain higher amounts of fluoride.
  • What’s at issue is the amount of fluoride in water.  There are proven benefits for public health that come from having the optimal level of fluoride in the water — just enough to protect our teeth.  In 2011, federal health officials offered a new recommended optimal level for water fluoridation: 0.7 parts per million.  That’s our goal: getting just enough to help all of us keep our teeth longer.

Are there better ways of delivering fluoride?

The Truth: Community water fluoridation is the most effective and most affordable way to protect dental health.

The Facts:

  • A 2003 study of fluoridation in Colorado concluded that “even in the current situation of widespread use of fluoride toothpaste," water fluoridation “remains effective and cost saving" at preventing cavities.
  • Studies conducted in communities that fluoridated water in the years after fluoride toothpastes were widely used have shown a lower rate of tooth decay than communities without fluoridated water.
  • The co-author of a 2010 study stated that research confirms the “the most effective source of fluoride to be water fluoridation."
  • Water fluoridation is inexpensive to maintain and saves money down the road.  The typical cost of fluoridating a local water system is between 40 cents and $2.70 per person, per year — less than the cost of a medium-sized latte from Starbucks each year.
  • For low-income individuals who are at higher risk of dental problems, fluoride tablets or rinses are a costly expense, which is why these products are not the “easy" answer that opponents of fluoridation claim they are.

Is adding fluoride like medication?

The Truth: Numerous scientific studies and reviews have recognized fluoride as an important mineral for healthy teeth.

The Facts:

  • Fluoride is not a medication.  The FDA regulates all medications and it does not regulate fluoride because it is a mineral. This mineral, fluoride when present at the right level in drinking water has two beneficial effects: preventing tooth decay and contributing to healthy bones.
  • U.S. court decisions have rejected the argument that fluoride is a “medication" that should not be allowed in water.  The American Journal of Public Health summarized one of these rulings, noting that “fluoride is not a medication, but rather a nutrient found naturally in some areas but deficient in others."
  • There are several examples of how everyday products are fortified to enhance the health of Americans — iodine is added to salt, folic acid is added to breads and cereals, and Vitamin D is added to milk.

Because we get fluoride in toothpaste, do we need it in our drinking water?

The Truth: Fluoridated water is the best way to protect everyone’s teeth from decay.

The Facts:

  • The benefits from water fluoridation build on those from fluoride in toothpaste.  Studies conducted in communities that fluoridated water in the years after fluoride toothpastes were common have shown a lower rate of tooth decay than communities without fluoridated water.
  • Fluoridated toothpaste reduces cavities by 20-25%, and water fluoridation reduces cavities by and additional 25-30% even when brushing is commonly practiced.
  • The CDC reviewed this question in January 2011.  After looking at all the ways we might get fluoride — including fluoride toothpaste — the CDC recommended that communities fluoridate water at 0.7 parts per million.  Any less than that puts the health of our teeth at risk.
  • Fluoride toothpaste alone is insufficient, which is why pediatricians and dentists often prescribe fluoride tablets to children living in non-fluoridated areas.

Is water fluoridation a ‘freedom of choice’ issue?

The Truth: Fluoridation is a smart public health policy where a modest community-wide investment benefits everyone, especially those who can’t afford to go to the dentist.

The Facts:

  • Fluoride exists naturally in virtually all water supplies, so it isn’t a question of choosing to get fluoride.  The only question is whether people receive the optimal level that’s documented to prevent tooth decay.
  • It is completely unrealistic to make water fluoridation a person-by-person or household-by-household choice.  The cost efficiency comes from a public water system fluoridating its entire supply.
  • Maintaining an optimal amount of fluoride in water is based on the principle that decisions about public health should be based on what is healthy for the entire community, not based on a handful of individuals whose extreme fears are not backed by the scientific evidence.
  • Fluoridation is not a local issue.  Every taxpayer in a state pays the price for the dental problems that result from tooth decay.  Three studies have shown that Medicaid dental costs are cut in half, showing the dramatic return on investment for water fluoridation.

Is fluorosis a health concern?

Truth: Mild fluorosis is not a health concern but is merely a slight cosmetic condition that includes mostly microscopic white speaks. Mild fluorosis is associated with stronger and healthier teeth.   Nearly all fluorosis in the U.S. is mild.  The National Research Council states that water fluoridation below 2ppm does not lead to mild fluorosis. Serious fluorosis in the U.S. is not caused by optimally fluoridated water.

The Facts:

  • Nearly all cases of fluorosis are mild — faint, white specks on teeth — that are usually so subtle that only a dentist will notice this condition.  Mild fluorosis does not cause pain, and it does not affect the health or function of the teeth.
  • The pictures of dark pitted teeth that anti-fluoride opponents circulate show severe cases of fluorosis, a condition that is virtually unheard of in the U.S.  Many of these photos are from India, and the reason is natural fluoride levels over there that are dramatically higher than the level used in the U.S. to fluoridate public water systems.  Common sense shows how misleading these photos are.  Think about it: Do one-third of the children’s teeth you see look brown and pitted?  No, they don’t.
  • In 2011, the CDC proposed a new level for fluoridation — 0.7 parts per million — that is expected to reduce the likelihood of fluorosis while continuing to protect teeth from decay.

There’s a warning label on fluoride toothpaste that tells you to ‘keep out of reach of children’, does that mean fluoride in water is a problem?

The Truth: Swallowing toothpaste in high amounts is a mild irritant because of several ingredients, but this does not relate to the proven safety of water fluoridation.

The Facts:

  • The warning label simply reflects the fact that toothpaste contains roughly 1,000 times as much fluoride per milligram as fluoridated water.  Even so, the American Dental Association (ADA) believes the warning label on toothpaste exaggerates the potential for negative health effects from swallowing toothpaste.  The ADA has stated that “a child could not absorb enough fluoride from toothpaste to cause a serious problem" and noted that fluoride toothpaste has an “excellent safety record."
  • Many vitamin labels have similar statements: “Keep out of reach of children."  That’s because almost anything has the potential for negative health effects if unsupervised children consume enough of it.  This also underscores why water fluoridation is the safest option, because no one can consume enough water to get anywhere near a harmful amount.

Is fluoridated water safe for babies?

The Truth: Yes, fluoridated water is safe for babies and young children.

The Facts:

  • The American Dental Association concludes that “it is safe to use fluoridated water to mix infant formula" and encourages parents to discuss any questions they may have with their dentists and pediatricians. The evidence does not support what anti-fluoride groups say.
  • A 2010 study examined the issue of fluorosis and infant formula, and reached the conclusion that “no general recommendations to avoid use of fluoridated water in reconstituting infant formula are warranted."  The researchers examined the condition’s impact on children and concluded that “the effect of mild fluorosis was not adverse and could even be favorable." Fluorosis nearly always appears as very faint white streaks on teeth.  The effect is usually so subtle that only a dentist would notice it during an examination.  Mild fluorosis does not cause pain, nor does it affect the function or health of the teeth.

Does water fluoridation cause cancer and other serious health problems?

The Truth: All the major health and medical organizations agree: optimally fluoridated water is both safe and effective, and is not linked to any of the health concerns opponents of fluoridation falsely claim.

The Facts:

  • The American Academy of Family Physicians, the Institute of Medicine and many other respected authorities endorse water fluoridation as safe.  The Centers for Disease Control and Prevention reports that “panels of experts from different health and scientific fields have provided strong evidence that water fluoridation is safe and effective."
  • More than 3,200 studies or reports had been published on the subject of fluoridation. Even after all of this research, the best that anti-fluoride groups can do is to claim that fluoride could cause or may cause one harm or another.  They can’t go beyond speculating because the evidence simply doesn’t back up the fear they are attempting to generate in the public mind.
  • The cancer claim is part of a pattern.  According to the American Council on Science and Health, “Historically, anti-fluoride activists have claimed, with no evidence, that fluoridation causes everything from cancer to mental disease."
  • A 2011 Harvard study found no link between fluoride and bone cancer.  This study reviewed hundreds of bone samples, and the study’s design was approved by the National Cancer Institute.  The study is significant because the National Research Council reported that if there were any type of cancer that fluoride might possibly be linked to, it would probably be bone cancer (because fluoride is drawn to bones).  The fact that this Harvard study found no link to bone cancer strengthens confidence that fluoride is unlikely to cause any form of cancer.
  • Opponents usually cite a 2006 study when they raise the cancer issue, but they omit the fact that the author of this study called it “an exploratory analysis."  Instead of measuring the actual fluoride level in bone, this 2006 study relied on surveys about water consumption, with a lot of potential for error.

Do European countries use fluoridation?

The Truth: Millions of people living in Europe are receiving the benefits of fluoride.

The Facts:

  • Europe has used a variety of programs to provide fluoride’s benefits to the public.  Water fluoridation is one of these programs.  Fluoridated water reaches 12 million Europeans, mostly residents of Great Britain, Ireland and Spain.  Fluoridated milk programs reach millions of additional Europeans, mostly in Eastern Europe.
  • Salt fluoridation is the most widely used approach in Europe.  In fact, at least 70 million Europeans consume fluoridated salt, and this method of fluoridation reaches most of the population in Germany and Switzerland.  These two countries have among the lowest rates of tooth decay in all of Europe.
  • Italy has not tried to create a national system of water fluoridation, but the main reasons are cultural and geological.  First, many Italians regularly drink bottled water.  Second, a number of areas in Italy have water supplies with natural fluoride levels that already reach the optimal level that prevents decay.
  • Technical challenges are a major reason why fluoridated water isn’t widespread in Europe.  In France and Switzerland, for example, water fluoridation is logistically difficult because of the terrain and because there are tens of thousands of separate sources for drinking water.  This is why Western Europe relies more on salt fluoridation, fluoride rinse programs and other means to get fluoride to the public

Does The National Research Council’s 2006 report say that “fluoride can have harmful effects?"

The Truth: Water fluoridation has been one of the most thoroughly studied subjects, including by the National Research Council, and the evidence shows it is safe and effective.

The Facts:

  • The National Research Council only studied and reported on optimally fluoridated water fluoridation in 1951, 1977, 1993, and most recently 2007 – each time reporting on the safety and effectiveness of water fluoridation. In 2006, the NRC did not study optimally fluoridated water but instead evaluated areas of the U.S. where the natural fluoride levels in well water or aquifers are unusually high.  These natural fluoride levels are about three to five times higher than the level used to fluoridate public water systems.
  • The National Research Council itself explained that its report was not an evaluation of the safety of water fluoridation.
  • The Centers for Disease Control and Prevention reviewed the NRC report and stated, “The report addresses the safety of high levels of fluoride in water that occur naturally, and does not question the use of lower levels of fluoride to prevent tooth decay."

Do studies show that water fluoridation is linked to lower IQ scores in children?

The Truth: Absolutely not. The flawed IQ studies being cited by anti-fluoride groups were in fact not about municipal water fluoridation but were poorly designed foreign studies about water systems with extremely high levels of fluoride up to 1500% higher than optimally fluoridated water. Even the authors of the study have said that their results do not relate to the safety of water fluoridation in the U.S.

The Facts:

  • The foreign studies that anti-fluoride activists cite involved fluoride levels that were at times 400% to 1500%  the level used to fluoridate drinking water in the U.S., and other contaminants such as lead or arsenic were generally not tested suggesting a strong possibility of bias. It is irresponsible to claim these studies have any real meaning for our situation in the U.S.
  • British researchers who evaluated these studies from China and other countries found “basic errors."  These researchers pointed out that the lower IQs could be traced to other factors, such as arsenic exposure, the burning of high-fluoride coal inside homes and the eating of contaminated grain.

Is fluoride a so called “by-product from the phosphate fertilizer industry?"

The Truth: Fluoride used to fluoridate public water systems is extracted from natural deposits of phosphate rock. It’s a mineral.

The Facts:

  • Much of the fluoride used to fluoridate water is extracted from phosphate rock, and so is phosphoric acid—an ingredient in Coke and Pepsi.  After fluoride is extracted from phosphate rock, much of that rock is later used to provide nutrients in plant fertilizers that will enrich the soil.  Opponents use this message a lot, maybe because they want to create the false impression that fluoride is synthetic or comes from fertilizer.
  • Cow’s milk produces the by-product cheese. Corn produces by-products including corn oil and cornstarch.  Fluoride is one example of many by-products that help to improve the quality of life or health.

The issue of fluoride being a “toxic waste byproduct" has specifically been reviewed by and found to be false:

This information comes from

National Research Council. “Earth Materials and Health: Research Priorities for Earth Science and Public Health." National Academies Press. 2007.

Readey v. St. Louis County Water Co., supranote 25 at 628, 631 for the court’s statement that it could not assume that the addition of 0.5 parts per million of fluoride to water that already contained 0.5 parts per million would result in infringement of any constitutional rights; Roemer, Ruth. “Water Fluoridation PH Responsibility and the Democratic Process."

American Journal of Public Health. Vol. 55 (9), 1965. (2) Chapman v. City of Shreveport, supra note 25 at 146.

ADA Fluoridation Facts, 2005.

American Dental Association Website.

U.S. Centers for Disease Control and Prevention. “Water Fluoridation: Nature’s Way to Prevent Tooth Decay," 2006, Pew Center on the States.

Nadereh Pourat and Gina Nicholson, “Unaffordable Dental Care Is Linked to Frequent School Absences," Health Policy Research Brief. (UCLA Center for Health Policy Research, Los Angeles, California) November 2009.

American Dental Association, “Statement on FDA Toothpaste Warning Labels," (July 19, 1997),

Advanced Dental Hygiene Practitioners Frequently Asked Questions. NNDHA Spring 2008, p. 8.

M. Neidell, K. Herzog and S. Glied, “The Association Between Community Water Fluoridation and Adult Tooth Loss," American Journal of Public Health, (2010).

M. Willis, C. Esqueda, and R. Schact, “Social Perceptions of Individuals Missing Upper Front Teeth," Perceptual and Motor Skills, 106 (2008): 423–435.

Thomas M. Leiendecker, Gary C. Martin et al., “2008 DOD Recruit Oral Health Survey: A Report on Clinical Findings and Treatment Need," Tri-Service Center for Oral Health Studies, (2008) 1 (accessed August 19, 2010).

B. Dye, et al., “Trends in Oral Health Status: United States, 1988-1994 and 1999-2004," Vital Health and Statistics Series 11, 248 (2007), Table 5, (accessed December 4, 2009).

National Cancer Institute Website. Water Fluoridation Fact Sheet. Accessed July 28, 2010.

Dr. Bill Bailey, CDC Podcast 7/17/2008.

National Health and Medical Research Council (Australia) (2007). “A systematic review of the efficacy and safety of fluoridation".

Centers for Disease Control and Prevention. “ Water Fluoridation" Homepage.

Centers for Disease Control and Prevention. “Public Health Service report on fluoride benefits and risks." Journal of the American Medical Association 1991; 266(8).

Mouden, L. “Fluoride: The Natural State of Water." Arkansas Dentistry; Summer 2005; 77(2): 15-16.

Kumar, J. “Geographic Variation in Medicaid Claims for Dental Procedures in New York State: Role of Fluoridation Under Contemporary Conditions". Public Health Reports.