Fluoride

Fluoride: A Comprehensive Encyclopedic Reference

1. Identity, Chemical Nature, and Natural Sources

Chemical Identity

Fluoride is an inorganic, monatomic anion of fluorine, with the chemical formula F⁻ (also written [F]⁻), whose salts are typically white or colorless. Fluoride is classified as a weak base, since it only partially associates in solution, but concentrated fluoride is corrosive and can attack the skin. Fluoride is a negatively charged ion of fluorine that is highly reactive and forms stable compounds with other elements, especially metals. It readily binds to calcium and certain other minerals, forming inorganic salts such as sodium fluoride and calcium fluoride.

The element fluorine is a pale, yellow gas found naturally in the Earth's crust. It is highly reactive, meaning it can combine with nearly any element on Earth. Fluoride is chemically related to fluorine, but they are not the same. Fluoride is a different chemical compound, created from salts that form when fluorine combines with minerals in soil or rocks. Fluoride is usually very stable and relatively unreactive, unlike its chemical relative fluorine.

Fluorine is estimated to be the 13th-most abundant element in Earth's crust and is widely dispersed in nature, entirely in the form of fluorides. Fluoride is the ionic form of the element fluorine, and it inhibits or reverses the initiation and progression of dental caries (tooth decay) and stimulates new bone formation.

Natural Sources and Environmental Occurrence

Fluoride is produced naturally through the weathering and erosion of fluoride-containing minerals, such as calcium fluoride and apatite. It is released into the atmosphere through volcanic activity and is commonly found in groundwater in concentrations varying by geographic region. Fluorine occurs in ionic forms, or combined with other chemicals in minerals like fluorspar, fluorapatite, and cryolite, and other compounds.

Fluoride is naturally present at low concentration in most fresh and saltwater sources and may also be present in rainwater. Seawater fluoride levels are usually in the range of 0.86 to 1.4 mg/L, and average 1.1 mg/L. Concentrations of fluorine can be quite high in areas of volcanic or geothermal activity, such as natural hot springs.

Fluoride is found naturally in soil, water, and many foods, and occurs naturally in the human body in bones and teeth. Food sources of fluoride include fluoridated water, tea, coffee, soybeans, and marine fish with bones such as canned salmon and mackerel.

Common Chemical Forms and Preparations

Any chemical compound that contains the fluoride ion is also known as a fluoride, such as calcium fluoride (CaF₂) and sodium fluoride (NaF). Fluorine combines with metals to make fluorides such as sodium fluoride and calcium fluoride, both white solids. Sodium fluoride dissolves easily in water, but calcium fluoride does not. Sodium fluoride, sodium fluorophosphate, and hexafluorosilicic acid are commonly used as food additives and in water fluoridation programs.

Fluoride in dietary supplements is usually in the form of sodium fluoride. Only a few dietary supplements contain fluoride, usually in the form of sodium fluoride. Most of these products are multivitamin/multimineral supplements, multivitamins plus fluoride, or supplements containing trace minerals only. Some fluoride supplements, usually intended for children, are in the form of drops.

Sodium fluoride is most often used as an additive to toothpaste and mouthwash. Calcium fluoride is the primary compound found in natural water sources. Fluoride preparations used in clinical settings have included sodium fluoride, slow-release fluoride, and monofluorophosphate, at various doses and in combination with calcium and vitamin D regimens.

2. Traditional and Historical Use

Early 20th-Century Discovery

The journey of fluoride in dentistry began in the early 1900s with a surprising observation by Dr. Frederick McKay, a dentist in Colorado Springs, Colorado. Dr. McKay noticed that many of his patients had brown stains, or "mottled enamel," on their teeth, but surprisingly, these teeth were also highly resistant to cavities. Dr. McKay teamed up with Dr. G.V. Black, a leading dental researcher of the time, to investigate further. Their studies revealed that the local drinking water contained unusually high levels of fluoride. While this excess fluoride caused discoloration (now known as dental fluorosis), it also made teeth more decay-resistant.

A phenomenon called "Brown Stain," associated with too much fluoride ingestion, was thought to be "typical caries" in a paper presented in 1904 before the German Society for Surgery. McKay and Black investigated what had been termed Colorado Brown Stain as early as 1916. In 1937, a dental preparation claiming to prevent decay was not favorably looked upon by the American Dental Association's (ADA) Council on Dental Therapeutics. The possibility of toxicity, conditions of usage, and absorption questions led to the ADA's conclusion that "The use of fluoride in dentifrices is unscientific and irrational, and therefore should not be permitted." At that time, dental problems were considered to be a personal matter.

The finding that the single greatest reason for rejecting people from the military in World War II was a result of poor oral health changed this sentiment. Very quickly, oral health became a national security issue and was recognized as a public health problem.

Introduction of Community Water Fluoridation

In 1945, the city of Grand Rapids, Michigan, became the first in the world to add fluoride to its public water supply as part of a controlled study. Studies in which the water supply of cities was artificially fluoridated were done in order to determine potential effectiveness of such a measure. Initial studies were placed in Grand Rapids, MI in 1945, with Muskegon, MI acting as the control city. Within a decade, cavity rates in children dropped significantly, establishing fluoride as a powerful preventive tool.

This process, known as community fluoridation, has been named as one of the 10 great public health achievements of the 20th century by the CDC.

Expansion of Fluoride Use

Untreated dental caries is the most common disease globally, and fluoride use at the population level is crucial for its control. Fluoride began to be incorporated into dental products — including toothpastes, gels, varnishes, and mouthrinses — during the latter half of the 20th century. An updated Cochrane review has found that the dental health benefits of adding fluoride to drinking water may be smaller now than before fluoride toothpaste was widely available, reflecting the historical progression from water fluoridation as the dominant delivery method toward multimodal topical delivery.

3. Key Constituents, Pharmacokinetics, and Mechanisms of Action

Absorption and Distribution

The pharmacokinetics of fluoride are driven primarily by pH and storage in bone. The acidic environment of the stomach promotes the conversion of fluoride ion to hydrogen fluoride, which is rapidly absorbed by passive diffusion from the stomach and small intestine. Approximately 70–90% of ingested fluoride is absorbed in the alimentary tract and, for very soluble forms such as sodium fluoride, absorption is almost 100%. Peak plasma concentrations are reached within 30 minutes. Calcified tissues such as bone and teeth readily incorporate fluoride.

Fluoride is readily incorporated into calcified tissues, such as bone and teeth, substituting for hydroxyls in hydroxyapatite crystals. Fluoride exchanges between body fluids and bone, both at the surface layer of bone (a short-term process) and in areas undergoing bone remodeling (a longer-term process). Most of the fluoride in the body, about 99%, is contained in bone.

Under most conditions, fluoride is rapidly and extensively absorbed from the gastrointestinal tract. The rate of gastric absorption is inversely related to the pH of the gastric contents. Overall absorption is reduced by calcium and certain other cations and by elevated plasma fluoride levels. Fluoride removal from plasma occurs by calcified tissue uptake and urinary excretion.

Mechanisms of Action in Dental Caries Prevention

Fluoride exerts its anti-cariogenic action when administered topically through three mechanisms: it inhibits tooth demineralization, promotes tooth remineralization, and inhibits plaque bacteria. Fluoride in drinking water and fluoride-containing products like toothpaste, mouthwash, and varnish work through these mechanisms.

When fluoride is present in oral fluids (i.e., saliva), fluorapatite, rather than hydroxyapatite, forms during the remineralization process. Fluoride ions (F⁻) replace hydroxyl groups (OH⁻) in the formation of the apatite crystal lattice. The presence of fluoride increases the rate of remineralization.

Under cariogenic conditions, carbohydrates are converted to acids by bacteria in the plaque biofilm. When the pH drops below 5.5, the biofilm fluid becomes undersaturated with phosphate ion and enamel dissolves to restore balance. When fluoride (F⁻) is present, fluorapatite is incorporated into demineralized enamel and subsequent demineralization is inhibited.

In the 1980s, it was established that fluoride controls caries mainly through its topical effect. Fluoride present in low, sustained concentrations (sub-ppm range) in the oral fluids during an acidic challenge is able to absorb to the surface of the apatite crystals, inhibiting demineralization.

Topical fluoride plays important roles in bacterial inhibition, fluorapatite formation, demineralization reduction, and remineralization enhancement. Fluoride acts on the acids of oral bacteria such as Mutans Streptococci (MS) and reduces the formation of these acids. This effect is considered a topical effect that leads to a reduction in tooth colonization by bacteria and thus leads to a decrease in enamel demineralization.

The persistent increase in salivary fluoride from average levels around 1 µmol/L to roughly 2–5 µmol/L is usually regarded as the key therapeutic ingredient in preventing dental caries. It is probable that salivary and plaque fluoride equilibria exist that play a role in fluoride's cariostatic regulation.

Fluoride used at high concentrations, more than 2500 ppm, can penetrate the dental biofilm, deliver fluoride to the tooth surface, and concentrate in incipient lesions. Fluoride decreases enamel demineralization and increases remineralization. A higher fluoride concentration also prolongs the fluoride retention in the oral cavity by forming a fluoride reservoir (calcium fluoride-like deposits) on the tooth surface and in dental biofilms.

Mechanisms of Action in Bone

Fluoride is attracted in particular to tissues that are calcium-rich, such as teeth and bones. At the tooth surface, for instance, it facilitates the attachment of calcium and phosphate ions, promoting the formation of fluorapatite crystals. In large enough doses, fluoride stimulates bone formation by osteoblastic stimulation, increases bone formation earlier and to a larger extent in trabecular bone compared to cortical bone, and increases spinal bone density. It also has the unique ability to stimulate new bone formation, and as such, it has been used as an experimental drug for the treatment of osteoporosis.

4. Scientific Evidence by Area of Use

4.1 Dental Caries Prevention — Water Fluoridation

The primary objectives of systematic review in this area have been to evaluate the effects of water fluoridation (artificial or natural) on the prevention of dental caries, and to evaluate the effects of water fluoridation on dental fluorosis.

Earlier systematic review (McDonagh 2000, also known as the York review) showed that fluoridation programs reduce caries as well as increase the risk of dental fluorosis. However, the review authors found insufficient evidence to draw conclusions regarding other potential harms or health disparities.

In an updated 2024 Cochrane systematic review of 21 studies of the initiation of water fluoridation, researchers found low-certainty evidence that initiation of community water fluoridation (CWF) may lead to a slightly greater change (reduction) in dmft (MD 0.24, 95% CI -0.03 to 0.52, P=0.09; 2 studies, 2908 children). It may also lead to a slightly greater change (increase) in the proportion of caries-free children with deciduous dentition and permanent dentition. These low-certainty findings were in favor of CWF, but the effect estimates include the possibility of benefit and no benefit.

The updated Cochrane review found that the dental health benefits of adding fluoride to drinking water may be smaller now than before fluoride toothpaste was widely available. This reflects the significance of baseline fluoride toothpaste use as a confounding factor in evaluating the incremental contribution of water fluoridation to caries reduction in the modern era.

4.2 Dental Caries Prevention — Topical Fluoride Products (Varnishes, Toothpastes, Mouthrinses, Gels)

A Cochrane review reported that professionally applied fluoride varnish can reduce caries incidence by 37% in primary dentition and by 43% in permanent dentition when applied two to four times annually. Questions remain about the optimal frequency and long-term sustainability of these effects in real-world clinical settings.

Another Cochrane review demonstrated that fluoride mouthrinses reduce caries incidence by about 27% in the permanent teeth of children and adolescents, confirming their value as an adjunctive preventive strategy.

Surveys show that children and teenagers who drink fluoridated water have fewer cavities. Also, adults who drink fluoridated water have fewer decayed and filled teeth and lose fewer teeth. Children who take dietary supplements that contain fluoride have a lower risk of tooth decay and tooth loss.

4.3 Dental Caries Prevention — Dietary Fluoride Supplements in Children

The available evidence suggests that dietary supplements containing fluoride can reduce rates of dental caries in children who lack access to fluoridated drinking water. No studies have assessed the impact of fluoride supplements on caries development in adults. The NIH ODS notes that no studies have addressed the dosage or duration of oral fluoride supplementation in pregnant women specifically, and that recommended doses for children are based on poor-quality evidence.

A 2011 Cochrane review by Tubert-Jeannin and colleagues and a 2008 JADA systematic review by Ismail and Hasson were among the primary systematic reviews cited by the FDA when evaluating ingestible fluoride drug products. Most research on systemic fluoride supplementation comes primarily from studies conducted from the 1950s through the 1990s, with most research focusing on prevention of tooth decay in children.

Like other nutrients, fluoride is transferred from a pregnant woman to her fetus, so a few studies have evaluated the use of fluoride supplements by pregnant women to prevent dental caries in their children. Studies suggest that giving a pregnant woman fluoride dietary supplements does not help prevent cavities in her child's teeth.

4.4 Bone Health and Osteoporosis

Because fluoride helps stimulate the formation of new bone, researchers have hypothesized that fluoride supplements might reduce bone fracture risk. However, research to date has provided only limited evidence supporting this hypothesis.

The ability of fluoride to increase BMD has been shown in several randomized controlled trials, as well as a systematic review by the National Osteoporosis Foundation. Specifically, spine BMD increased by 7.9% (95% CI: 5.4%, 10.5%, p<0.001, n=1,774) and hip BMD by 2.1% (95% CI: 0.9%, 3.4%, p<0.01, n=1,434) after treatment with fluoride, but with evidence of significant heterogeneity.

Although fluoride has an ability to increase BMD at the lumbar spine, it does not result in a reduction of vertebral fractures. In increasing the dose of fluoride, one increases the risk of non-vertebral fracture and gastrointestinal side effects without any effect on the vertebral fracture rate.

Histomorphometric studies suggest that although fluoride increases bone mineral density, there is a corresponding decrease in elasticity and strength of the bone tissue, and fluoride is thought to alter the crystalline structure of the bone tissue.

The findings of observational studies on the impact of fluoride levels in water on bone mineral density and fracture risk have been mixed. A study of 7,129 white women found no significant differences in BMD or risk of hip, vertebral, wrist, or humerus fracture between those exposed and those not exposed to fluoridated water between 1950 and 1994. In contrast, in a study in 8,266 Chinese residents age 50 years or older, people with access to water fluoride levels of approximately 1 mg/L had a lower overall risk of fractures, but not of hip fractures, than those with access to water containing negligible fluoride levels.

Evidence strength for bone health: Fluoride at high pharmacological doses reliably increases BMD, particularly at the lumbar spine, but the clinical evidence does not demonstrate a consistent reduction in fracture rates, and higher doses are associated with increased non-vertebral fracture risk. Evidence for fracture prevention from water fluoridation at public health concentrations is mixed and inconclusive.

5. Body Systems and Health Areas Associated with Fluoride

5.1 Oral and Dental System

Fluoride is defined as the form of fluorine that naturally occurs and is considered a beneficial nutrient, essential for the integrity of bones and teeth. It is added to drinking water and is found in various food sources, contributing to increased tooth mineralization and bone density while reducing the risk of dental caries. The oral system — encompassing enamel, dentin, cementum, and the plaque biofilm — is the primary site at which fluoride's most well-documented physiological actions occur.

5.2 Skeletal System

Owing to its high affinity for calcium, fluoride is mainly associated with calcified tissues. Fluoride is readily incorporated into calcified tissues, such as bone and teeth, substituting for hydroxyls in hydroxyapatite crystals. Fluoride exchanges between body fluids and bone, both at the surface layer of bone (a short-term process) and in areas undergoing bone remodeling (a longer-term process). Most of the fluoride in the body, about 99%, is contained in bone.

5.3 Neurological System

A 2006 evaluation by the National Research Council (NRC) found support for an association between consumption of high levels of naturally occurring fluoride in drinking water and adverse neurological effects in humans and recommended further investigation. The evidence reviewed at that time was from dental and skeletal fluorosis-endemic regions of China. Since the NRC evaluation, the number and location of studies examining cognitive and neurobehavioral effects of fluoride in humans have grown considerably, including several recent North American prospective cohort studies evaluating prenatal fluoride exposure.

The 2024 NTP systematic review finds, with moderate confidence, that higher estimated fluoride exposures (e.g., drinking water fluoride concentrations that exceed the World Health Organization Guidelines for Drinking-water Quality of 1.5 mg/L of fluoride) are consistently associated with lower IQ in children. More studies are needed to fully understand the potential for lower fluoride exposure to affect children's IQ.

Specific molecular targets for most of the effects of fluoride on neurodevelopment remain to be established, and many of the findings from in vitro studies were only observed in the millimolar range, in studies with human pulmonary epithelial cells, human hepatocellular carcinoma cells, rat hippocampal neurons, and mouse hepatocytes. The in vivo relevance of such concentrations in humans is questionable, since fluoride plasma concentrations in healthy adults generally range between 0.4 and 3.0 µM.

5.4 Endocrine and Other Systems

Health concerns cited in relation to fluoride include skeletal fluorosis, lower intelligence quotient (IQ) and other neurological effects, cancer, and endocrine disruption. In 2006, an expert panel convened by the US National Academies concluded that there was growing evidence that fluoride at levels of 2 to 4 mg/L in drinking water may increase the risk of skeletal fluorosis, bone fractures, IQ deficits, and assorted endocrine and other effects, and that more research was needed.

Fluoride is highly electronegative and can disrupt hydrogen bonds and alter enzymatic activity. This is especially relevant in biological systems, where fluoride can disrupt hydrogen bonds and alter enzymatic activity, depending on its concentration and the types of cells and tissues with which it interacts.

6. Dosage Forms and Reported Dosages

Adequate Intake (AI) Values

Intake recommendations for fluoride and other nutrients are provided in the Dietary Reference Intakes (DRIs) developed by the Food and Nutrition Board (FNB) at the National Academies of Sciences, Engineering, and Medicine. DRI is the general term for a set of reference values used for planning and assessing nutrient intakes of healthy people. Because evidence was insufficient to establish an RDA, an Adequate Intake (AI) was established for fluoride. It is recommended that females 18 years and older consume 3 mg of fluoride daily. It is recommended that males 18 years of age consume 3 mg, and males 19 years and older consume 4 mg daily.

Upper tolerable intake levels (ULs) for children are set by age: 0.7 mg for 0–6 months, 0.9 mg for 7–12 months, 1.3 mg for 1–3 years, 2.2 mg for 4–8 years, and 10 mg for children 8 years and older.

Dietary Fluoride Supplement Dosages in Children

Birth to 6 months: No fluoride supplements are recommended (minimal risk of deficiency at this age). Ages 6 months to 3 years: If the local water supply has <0.3 ppm fluoride, prescribe 0.25 mg fluoride per day, typically as liquid drops for infants. No supplement is needed if water fluoride ≥0.3 ppm.

Ages 3–6 years: If water fluoride is <0.3 ppm, give 0.50 mg/day; if water fluoride is moderate (0.3–0.6 ppm), give 0.25 mg/day. No supplement is needed if water fluoride ≥0.6 ppm. Ages 6–16 years: If water fluoride is <0.3 ppm, give 1.0 mg/day; if water is 0.3–0.6 ppm, give 0.50 mg/day.

Supplements are available only by prescription and are intended for use by children living in areas with low water fluoride concentrations so that their intake is similar to that by children whose water fluoride concentrations are approximately 1.0 mg/liter. Supplements are rarely prescribed for adults.

Pharmacological Doses Used in Osteoporosis Clinical Trials

In studies of osteoporosis treatment with fluoride, doses of fluoride 30 ± 8 mg/day (equivalent to 66 ± 17 mg NaF/day) with calcium 1500 mg/day for 28 ± 18 months have been assessed. The clinical trials predominantly showed increased bone density in several sites associated with fluoride treatment of 9–22.6 mg fluoride per day for one to four years.

Water Fluoridation Standards

The World Health Organization (WHO) set a safe water guideline of 1.5 mg/L of fluoride in drinking water (first established in 1984 and reaffirmed in 1993 and 2011), which is recommended to protect against increasing risk of dental and skeletal fluorosis. Estimates of fluoride intake among U.S. and Canadian adults have ranged from <1.0 mg fluoride per day in nonfluoridated areas to 1–3 mg fluoride per day in fluoridated areas.

7. Safety Considerations

Dental Fluorosis

Excessive fluoride intake during the period of tooth development can cause dental fluorosis. When constantly consumed in large amounts for a long time, fluoride can cause chronic disease. The first sign of chronic toxicity is observed through changes in the dental organs, which show a creamy-white surface, white and yellow spots, lines or striations, and porosity. In more severe injuries, the tooth enamel becomes weak, brittle, prone to fractures or ruptures, and has significant areas of wear and tear.

Some evidence shows that the prevalence of mild enamel fluorosis in the primary teeth, but not the permanent teeth, is higher among formula-fed infants than infants fed cow's milk, which has a low fluoride concentration similar to that of human milk.

Skeletal Fluorosis

Dental fluorosis is one of the first clinical signs of fluorosis and can be associated with skeletal and systemic fluorosis, affecting the bones, joints, organs, and entire systems. The NRC report concluded that the Maximum Contaminant Level Goal (MCLG), 4 mg/L, should be lowered to protect against severe enamel fluorosis and reduce the risk of bone fractures associated with skeletal fluorosis.

Tolerable Upper Intake Level

Fluoride is likely safe when consumed in doses below the tolerable upper intake level (UL) of 10 mg of elemental fluoride daily. Taking high doses long-term can weaken bones and ligaments, and cause muscle weakness and nervous system problems.

Neurodevelopmental Safety Signal (2024 NTP Review)

The 2024 NTP systematic review found, with moderate confidence, that higher estimated fluoride exposures (e.g., as in drinking water fluoride concentrations that exceed the WHO guideline of 1.5 mg/L) are consistently associated with lower IQ in children. More studies are needed to fully understand the potential for lower fluoride exposure to affect children's IQ. This finding is specific to exposures above the WHO guideline value; the review did not establish a definitive effect at water fluoridation levels typical in the United States (0.7 mg/L).

Gastrointestinal Effects at High Doses

The risk for gastrointestinal side effects in fluoride therapy for osteoporosis was not significant at two years but was increased at four years in the treated group (RR 2.18, 95% CI: 1.69–4.57), especially if fluoride was used at high doses and in a non-slow-release form.

Interactions with Calcium and Other Minerals

Fluoride absorption is reduced by increased stomach pH and increased concentrations of calcium, magnesium, and aluminum. At high concentrations, those metals form relatively insoluble fluoride salts. Fluoride has no known, clinically relevant interactions with medications.

Infant Formula Preparation

Fluoride intake among infants varies widely, especially during the first 6 months of life, depending on whether the infant is fed human milk or formula and whether the formula is ready-to-feed or requires reconstitution with water. Human milk-fed infants receive about 0.01 mg/day (0.001 to 0.003 mg/kg). Infants fed a formula reconstituted with fluoridated water may receive as much as 1.0 mg/day.

References

• NIH Office of Dietary Supplements — Fluoride Health Professional Fact Sheet
• NIH Office of Dietary Supplements — Fluoride Consumer Fact Sheet
• NIH/National Academies — Dietary Reference Intakes for Calcium, Phosphorus, Magnesium, Vitamin D, and Fluoride (Chapter on Fluoride)
• NTP Monograph on Fluoride Exposure and Neurodevelopment and Cognition: A Systematic Review (2024)
• NTP Monograph (PMC Full Text) — Fluoride Exposure and Neurodevelopment, 2024
• Cochrane Library — Water Fluoridation for the Prevention of Dental Caries (2024 Update)
• Cochrane Library — Water Fluoridation for the Prevention of Dental Caries (2015)
• PMC — Fluoride for Treating Postmenopausal Osteoporosis (Cochrane Review)
• PMC — Role of Fluoride in Dentistry: A Narrative Review
• StatPearls/NCBI — The Role of Fluoride on Caries Prevention
• PMC — Fluoride Varnishes for Preventing Occlusal Dental Caries: A Review
• PubMed — Mechanisms of Action of Fluoride for Caries Control
• MDPI Healthcare — Fluoride in Dental Caries Prevention and Treatment: Mechanisms, Clinical Evidence, and Public Health Perspectives (2025)
• NCBI — Pharmacokinetics and Concentrations of Fluoride Measured in Tissue, Blood, Urine, or Bone (NTP Research Report)
• National Academies — Pharmacokinetics of Fluoride (Chapter 3, Fluoride in Drinking Water: A Scientific Review of EPA's Standards)
• PubMed — Intake and Metabolism of Fluoride (Whitford, Adv Dent Res, 1994)
• PMC — Toxicity of Fluoride: Critical Evaluation of Evidence for Human Developmental Neurotoxicity
• Britannica — Fluoride: Definition, Uses, Sources, Biological Effects
• Chemical Safety Facts — Fluoride
• ATSDR — Public Health Statement: Fluorides, Hydrogen Fluoride, and Fluorine
• PMC — The Use of Fluorides in Public Health: 65 Years of History and Challenges from Brazil (2022)
• NCBI/DARE — Water Fluoridation, Osteoporosis, Fractures: Recent Developments
• NCBI/DARE — Effects of Treatment with Fluoride on Bone Mineral Density and Fracture Risk: A Meta-Analysis
• PubMed — The Role of Fluoride in the Prevention of Osteoporosis
• American Dental Association — Fluoride Supplements: A Brief Overview
• CDC MMWR — Recommendations for Using Fluoride to Prevent and Control Dental Caries in the United States
• FDA — Fluoride Ingestible Drug Products: Scientific Evaluation
• PMC — Editorial: Fluoride Exposure, Dental Fluorosis, and Health
• StatPearls/NCBI — Remineralization of Initial Carious Lesions
• PMC — Fluoride Intake Through Dental Care Products (2022)