Fluoride, Oral Health & Functional Dentistry

Fluoride is one of those substances where the distance between “public health triumph” and “legitimate concern” has narrowed considerably over the past two decades — yet the conversation remains oddly frozen in the 1950s. On one side, categorical endorsement. On the other, categorical rejection. The truth, as usual, lives in the space between certainty and curiosity.

What follows is an attempt to lay out what we actually know — the mechanisms, the evidence for harm, the alternatives that work, and the broader framework of functional oral care that makes the fluoride debate, while important, only one piece of a much larger picture.

Fluoride Mechanisms: Topical vs. Systemic

For decades, the operating assumption was that fluoride’s primary benefit came from systemic exposure — swallowing it in water or supplements so that it would incorporate into developing enamel from the inside, making teeth structurally more resistant to acid. This was the rationale behind water fluoridation and fluoride supplementation for children.

In 1999, the CDC issued a pivotal clarification. In their report Achievements in Public Health, 1900-1999: Fluoridation of Drinking Water to Prevent Dental Caries, they acknowledged that fluoride’s predominant cariostatic mechanism is topical, not systemic. Fluoride works primarily by being present at the tooth surface — where it inhibits demineralization, enhances remineralization, and disrupts bacterial metabolism in plaque.

This distinction matters enormously. If the benefit is topical, then swallowing fluoride — absorbing it into every tissue of the body via the GI tract — is not necessary to achieve dental protection. You could apply it directly to teeth (as in toothpaste or rinse) and get the benefit without the systemic exposure. This is exactly the approach that most of Europe has adopted.

The Concerns: What the Evidence Shows

Dental Fluorosis

Dental fluorosis — white spots, streaking, or in severe cases brown pitting of the enamel — occurs when developing teeth are exposed to excess fluoride during childhood. The CDC’s own data show that dental fluorosis prevalence has increased significantly since the introduction of water fluoridation. A 2010 CDC survey found that 41% of adolescents aged 12-15 had some degree of dental fluorosis, up from 22.6% in a 1986-1987 survey.

While most fluorosis is classified as “mild” (white spots), it represents a biomarker of overexposure — the body is telling us that fluoride intake exceeds the dose at which it can be safely incorporated into developing tissues.

Thyroid Disruption

Fluoride was used as a thyroid-suppressing medication in the 1930s-1950s at doses of 2-10mg per day — doses achievable through a combination of fluoridated water, toothpaste, beverages, and processed foods.

Stephen Peckham and Niyi Awofeso published findings in 2015 in the Journal of Epidemiology and Community Health showing that areas of England with fluoridated water had nearly double the rate of hypothyroidism compared to non-fluoridated areas, even after controlling for demographics. Ashley Malin and colleagues (2018, Environment International) found that among iodine-deficient individuals in Canada, higher fluoride exposure was significantly associated with hypothyroidism.

Fluoride inhibits thyroid function through multiple mechanisms: it competes with iodine for uptake at the sodium-iodide symporter, it inhibits thyroid peroxidase activity (the enzyme that produces thyroid hormone), and it may increase TSH levels. For the millions of people with subclinical hypothyroidism or borderline iodine status, chronic fluoride exposure may be a meaningful contributor.

Neurodevelopment

This is where the evidence has shifted most dramatically. Bashash et al. published in Environmental Health Perspectives in 2017 a prospective birth cohort study from Mexico City showing that higher maternal urinary fluoride during pregnancy was associated with lower IQ scores in offspring at ages 4 and 6-12. Each 0.5 mg/L increase in maternal urinary fluoride was associated with a 3.15-point decrease in IQ at age 6-12.

The National Toxicology Program (NTP) conducted a systematic review and meta-analysis, concluding that fluoride is “presumed to be a cognitive neurodevelopmental hazard to humans” based on a consistent pattern across 72 studies from multiple countries showing associations between fluoride exposure and reduced IQ in children. The NTP’s final report, after years of review and political controversy, upheld this conclusion.

In 2024, a federal court ruled in Food & Water Watch v. EPA that the evidence showed a sufficiently plausible link between fluoride at levels found in U.S. drinking water and neurodevelopmental harm to warrant regulatory action. This was a landmark legal acknowledgment of the science.

Pineal Gland Calcification

Jennifer Luke’s 2001 doctoral research at the University of Surrey demonstrated that the pineal gland accumulates more fluoride than any other soft tissue in the body. The human pineal gland was found to contain fluoride concentrations comparable to those in teeth and bone — up to 21,000 ppm in aged specimens. This fluoride accumulation correlated with pineal calcification and, in animal studies, with earlier onset of puberty and reduced melatonin production.

The pineal gland produces melatonin — the body’s master circadian regulator, a potent antioxidant, and an immune modulator. Fluoride-driven calcification and functional impairment of the pineal gland could have implications for sleep, hormonal timing, and antioxidant defense. This area remains under-researched relative to its potential significance.

Bone Health

At high chronic doses, fluoride causes skeletal fluorosis — a painful condition involving bone thickening, calcification of ligaments, joint stiffness, and fractures. This is well documented in regions with naturally high water fluoride (India, China, parts of Africa). At lower doses relevant to water fluoridation, the evidence is mixed but includes:

• Increased hip fracture risk in some epidemiological studies
• Altered bone crystal structure that may increase brittleness despite increased density
• Sodium fluoride was previously used as an osteoporosis treatment but was abandoned when trials showed increased vertebral bone density but increased non-vertebral fractures — the bone was denser but weaker

Water Fluoridation: Global Perspective

Water fluoridation began in Grand Rapids, Michigan in 1945, and approximately 73% of the U.S. population on community water systems currently receives fluoridated water at 0.7 mg/L.

The European perspective is strikingly different. Approximately 97% of Western Europe does not fluoridate its water supply. Countries including Germany, France, Austria, Belgium, the Netherlands, Sweden, Denmark, Norway, Finland, Switzerland, and Japan have either never fluoridated, discontinued the practice, or rely exclusively on topical fluoride application. Their dental caries rates have declined at the same rate as fluoridated countries — suggesting that improved hygiene, diet awareness, and topical fluoride in toothpaste are sufficient.

This is not a fringe position. The majority of developed nations have concluded that systemic fluoride exposure through water is unnecessary, and that the risk-benefit balance favors topical application only.

Alternatives to Fluoride for Remineralization

If not fluoride, then what? This is where functional dentistry gets genuinely exciting.

Hydroxyapatite (n-HAp)

Nano-hydroxyapatite is the synthetic form of the mineral that comprises 97% of tooth enamel and 70% of dentin. Japan has used it as the standard remineralization agent in toothpaste since the 1980s, when NASA originally developed it for astronauts experiencing bone and tooth demineralization in space.

Hardy Limeback — a former president of the Canadian Association for Dental Research and once a prominent fluoride advocate who publicly reversed his position — co-authored research in 2023 confirming that hydroxyapatite toothpaste is equivalent to fluoride toothpaste for caries prevention and remineralization. A 2019 systematic review in the Journal of Dentistry found that hydroxyapatite was at least as effective as fluoride for remineralization of early enamel lesions.

Hydroxyapatite works by directly depositing mineral into demineralized enamel — filling the microscopic pores and defects that represent the earliest stage of cavity formation. It is biomimetic: the body recognizes it as its own material. It is non-toxic if swallowed, making it particularly appropriate for children. And it reduces sensitivity by physically occluding open dentinal tubules.

Available in: Boka, RiseWell, Davids, Apagard (Japanese), CariFree.

Xylitol

Xylitol is a five-carbon sugar alcohol that cavity-causing bacteria (Streptococcus mutans) cannot metabolize. They take it up but cannot process it, wasting energy in a futile metabolic loop. Over time, xylitol exposure selects against S. mutans populations and reduces their ability to adhere to tooth surfaces and form plaque biofilm.

Kauko Makinen and colleagues at the University of Turku, Finland, conducted the original landmark studies in the 1970s (the Turku Sugar Studies) and subsequent research establishing that 6-10 grams of xylitol daily, divided into 3-5 exposures (ideally after meals), significantly reduces dental caries incidence. The effect is dose-dependent and frequency-dependent — regular brief exposures throughout the day are more effective than a single large dose.

Delivery: xylitol gum (2-3 pieces after meals), xylitol mints, xylitol nasal spray (also reduces upper respiratory infections), or xylitol rinse. Choose products where xylitol is the first listed sweetener. Note: xylitol is toxic to dogs — keep xylitol products away from pets.

MI Paste (CPP-ACP)

Recaldent (CPP-ACP) — casein phosphopeptide-amorphous calcium phosphate — is a milk-derived protein that delivers bioavailable calcium and phosphate directly to the tooth surface. It stabilizes these minerals in a supersaturated state, making them readily available for enamel remineralization.

MI Paste (by GC America) applies this technology in a topical crème. It is particularly useful for:

• Post-orthodontic white spot lesions
• Early enamel demineralization
• Xerostomia (dry mouth) patients who lack saliva’s natural remineralizing capacity
• Sensitivity reduction

Apply a pea-sized amount to teeth after brushing, leave on for 3 minutes, then spit (do not rinse). Caution: contains milk protein — not suitable for those with casein allergy.

Functional Oral Care Routine

A comprehensive daily oral care routine that does not rely on fluoride:

Morning:

1. Tongue scraping — a stainless steel or copper tongue scraper removes the overnight bacterial biofilm, volatile sulfur compounds, and debris from the tongue surface. 5-10 gentle strokes from back to front. This alone can reduce oral bacterial load by 30-50%.
2. Oil pulling — 1 tablespoon of organic coconut oil or sesame oil, swished gently for 10-20 minutes (while showering, preparing food, etc.). Spit into trash (not sink — it solidifies). The oil mechanically traps bacteria, reduces plaque formation, and delivers medium-chain fatty acids (lauric acid in coconut oil) that have antimicrobial properties. Asokan’s research (2009) demonstrated that oil pulling with sesame oil was comparable to chlorhexidine for plaque reduction.
3. Brush with hydroxyapatite toothpaste — soft-bristle brush, modified Bass technique, 2 minutes. Allow the hydroxyapatite to contact teeth by not rinsing aggressively afterward — spit but do not rinse, or rinse minimally.

After Meals: 4. Xylitol gum or mint — 2-3 pieces after each meal, chewed for 5-10 minutes. Stimulates saliva, delivers xylitol to tooth surfaces. 5. Water swishing — if brushing is not possible after eating, vigorously swishing water neutralizes acids and clears food debris.

Evening: 6. Interdental care — floss, interdental brushes, or a water flosser (Waterpik). The proximal surfaces between teeth are the primary sites where caries develop, and brushing alone cannot reach them. Water flossers are particularly effective for gum health and around dental work. 7. Brush with hydroxyapatite toothpaste. 8. Optional: MI Paste application or oral probiotic lozenge (S. salivarius K12/M18) dissolved slowly after final brushing.

Diet for Dental Health

Weston A. Price traveled the world in the 1930s studying indigenous populations with virtually no dental decay. His observations, documented in Nutrition and Physical Degeneration, identified consistent dietary patterns among cavity-free populations:

Fat-Soluble Vitamins A, D, and K2: Price called K2 “Activator X” — the unknown nutrient present in the butter, organ meats, and fermented foods of healthy traditional diets. We now know this is menaquinone-7 (K2-MK7), which directs calcium into bones and teeth and away from soft tissues. Without K2, calcium supplementation or high calcium intake may calcify arteries while leaving teeth vulnerable.

• Vitamin A (retinol): 5,000-10,000 IU daily from liver, cod liver oil, or preformed retinol. Essential for enamel formation and immune function of oral mucosa.
• Vitamin D3: 2,000-5,000 IU daily, maintaining serum 25-OH-D at 50-70 ng/mL. Controls calcium and phosphorus metabolism critical for remineralization.
• Vitamin K2 (MK-7): 100-200mcg daily from natto, hard cheeses, goose liver, or supplementation. Activates osteocalcin (which deposits calcium into teeth and bone) and matrix GLA protein (which prevents soft tissue calcification).

Minerals: Calcium (1,000mg daily from food — dairy, bone broth, sardines, greens), phosphorus (naturally paired with calcium in whole foods), and magnesium (400-600mg daily) maintain the mineral reservoir from which saliva draws for remineralization.

Reduce Sugar and Acid Exposure: Every sugar exposure drops oral pH below 5.5 — the critical threshold at which enamel dissolves. It takes saliva 20-30 minutes to restore pH after each acid challenge. Frequency of sugar exposure matters more than total amount. Three sodas sipped throughout the day cause more damage than the same volume consumed at once.

Phytic Acid Reduction: Phytic acid in unsprouted grains, nuts, seeds, and legumes binds calcium, phosphorus, and zinc in the gut, reducing mineral absorption. Traditional food preparation — soaking, sprouting, fermenting, and sourdough leavening — reduces phytic acid content. Ramiel Nagel’s Cure Tooth Decay popularized this concept, building on Price’s work.

Saliva Optimization

Saliva is the body’s built-in remineralization system. It delivers calcium, phosphate, and bicarbonate to tooth surfaces, neutralizes acids, contains antimicrobial proteins (lysozyme, lactoferrin, IgA), and physically rinses the mouth. Anything that impairs saliva is a dental risk factor.

Hydration: Chronic mild dehydration — the norm for most adults — reduces salivary flow. Minimum 8 glasses of water daily, more with exercise or dry climate.

Nasal Breathing: Mouth breathing dries the oral cavity, reduces salivary buffering, and allows pH to drop. The switch to habitual nasal breathing — reinforced through Buteyko techniques and myofunctional therapy — is one of the most impactful oral health interventions available.

Medications: Over 500 commonly prescribed medications list dry mouth as a side effect — including antidepressants, antihistamines, blood pressure medications, and diuretics. If medication-induced dry mouth is present, compensate with xylitol lozenges, frequent water sipping, and saliva substitutes.

pH and Remineralization Cycles: The mouth cycles between demineralization (when pH drops below 5.5 after eating) and remineralization (when saliva restores pH above 5.5). Healthy teeth survive this cycle indefinitely — as long as remineralization outpaces demineralization. The entire functional oral care approach is designed to tip this balance: reduce acid challenges (less sugar, less frequent eating), support remineralization (hydroxyapatite, minerals, saliva), and maintain a healthy microbial community that does not overproduce acid.

Biological Dentistry Principles

Biological dentistry — also called holistic, integrative, or biocompatible dentistry — applies the functional medicine framework to oral health. Its core principles include:

Biocompatibility Testing: Not all dental materials are tolerated by all patients. The Clifford Materials Reactivity Test (serum test) and MELISA test (lymphocyte transformation test) identify individual sensitivities to specific composites, metals, cements, and other dental materials before they are placed in the mouth.

Ozone Dentistry: Medical-grade ozone (O3) is used therapeutically in biological dentistry for:

• Sterilizing cavities before filling (reducing recurrent decay)
• Treating early enamel lesions without drilling (ozone reverses early demineralization)
• Disinfecting root canals and extraction sites
• Treating periodontal pockets

Ozone is a powerful oxidant that kills bacteria, viruses, and fungi on contact, then breaks down to oxygen. It stimulates local immune response and enhances healing.

Minimally Invasive Approaches: Air abrasion instead of drilling for small cavities. Ozone treatment for early lesions. Remineralization protocols before resorting to restorative work. The biological dentist’s first question is not “how do I fill this?” but “can this be reversed?”

Mercury-Free and Mercury-Safe Practice: No new amalgam placement, and SMART protocol for removal of existing amalgams. This is foundational to biological dentistry.

Whole-Person Assessment: Recognizing that oral health affects and is affected by systemic health. Collaborating with functional medicine practitioners, naturopaths, and other providers. Considering the meridian connections, the airway, the gut, and the immune system — not just the teeth in isolation.

The Integration

The fluoride debate, important as it is, often obscures the larger picture. Whether or not you use fluoride, the foundations of dental health are the same: nutrient-dense whole foods, adequate fat-soluble vitamins, mineral balance, a healthy oral microbiome, sufficient saliva, nasal breathing, low sugar frequency, and regular gentle mechanical cleaning.

Fluoride was never the reason indigenous populations had perfect teeth. And its absence is not the reason modern populations lose them. The cause is deeper — it is dietary, microbial, developmental, and systemic. Functional dentistry addresses that depth. A tube of toothpaste, whatever it contains, is the last step — not the first.

What if the most important thing for your teeth was not what you put on them, but what you put in your body and how you breathe?