Fluoride
On this page 18 sections
General
- Galagan and Vermillion (1957) established a formula to calculate the optimal fluoride concentration in community drinking water based on the annual average maximum daily air temperature
- Fluoride action on carbs for reducing caries = inhibits enolase
- Fluoride least effective = Pits and Fissures
- Zeigler = introduced Milk fluoridation
- Anti caries amount of Fluoride in salt = 1.5 mg F / 5mg salt or 200-250 mg /kg
- Daily dose for children = 1.2mg
- Daily dose for adults = 2-2.2 mg
- Fluoride content more in = Cheese
- Fluoride found higher ppm in = Tea
- Vipeholm study = To find out role of sticky and non sticky sugar in caries
- Fluoride carried by Plasma and RBC
- Salt fluoridation was first introduced in Switzerland in 1955 by Dr. Hans Wespi.
- Applying resins to fissures for sealants introduced by = Buonocore
- 5mg acute toxicity = Require hospitalisation
- Nephrotoxic at = 850-950 ug/dL
- School water fluoridation first in = 1954 at St. Thomas, Virgin Islands (at the Lincoln School) as a pilot study by the U.S. Public Health Service
HISTORY OF FLUORIDE
1901 — Frederick McKay
“mottled enamel”
1916 — Black & McKay
G.V. Black and Frederick McKay investigated mottled enamel.
Teeth affected by mottling often appeared to have less dental caries.
1930s — H. Trendley Dean
H. Trendley Dean systematically investigated fluoride concentration in drinking water and dental fluorosis.
1931 - Churchill
identified fluoride as the cause of mottled enamel in 1931
1945 — Community water fluoridation
Grand Rapids, Michigan became the first city to begin community water fluoridation in 1945.
OPTIMAL FLUORIDE IN DRINKING WATER
The current U.S. Public Health Service recommended concentration is: 0.7 ppm
Older textbooks may say: 1 ppm
Recommended daily fluoride intake
| Age | Recommended fluoride/day |
|---|---|
| 0–6 months | 0.01 mg/day |
| 7–12 months | 0.5 mg/day |
| 1–3 years | 0.7 mg/day |
| 4–8 years | 1.0 mg/day |
| 9–13 years | 2.0 mg/day |
| 14–18 years | 3.0 mg/day |
| Adult males ≥19 yr | 4.0 mg/day |
| Adult females ≥19 yr | 3.0 mg/day |
| Pregnancy | 3.0 mg/day |
| Lactation | 3.0 mg/day |
FLUORIDE SUPPLEMENTS
AGE-BASED DOSES
ADA schedule
| Age | Water <0.3 ppm | Water 0.3–0.6 ppm | Water >0.6 ppm |
|---|---|---|---|
| Birth–6 months | None | None | None |
| 6 months–3 years | 0.25 mg/day | None | None |
| 3–6 years | 0.50 mg/day | 0.25 mg/day | None |
| 6–16 years | 1.0 mg/day | 0.50 mg/day | None |
Sources
TOOTHPASTE
| Product | Fluoride concentration | Notes |
|---|---|---|
| Children's/standard fluoride toothpaste | ~1,000–1,500 ppm F | Decreases caries by 20-35% |
| Prescription high-fluoride toothpaste | 5,000 ppm F | |
| 1.1% sodium fluoride toothpaste | 5,000 ppm F | |
| Sodium monofluorophosphate toothpaste | Usually ~1,000–1,500 ppm F | |
| Stannous fluoride toothpaste | Usually ~1,000–1,500 ppm F |
FLUORIDE MOUTH RINSES
| Mouthrinse | NaF concentration | Fluoride ion |
|---|---|---|
| Daily rinse | 0.05% NaF | 230 ppm F |
| Weekly rinse | 0.2% NaF | 920 ppm F |
| Prescription high-strength rinse | ~0.09% F | ~900 ppm F |
PROFESSIONAL FLUORIDE GELS & FOAMS
| Preparation | Concentration | Approx. F⁻ | Notes | Time | AKA |
|---|---|---|---|---|---|
| APF gel | 1.23% fluoride ion | 12,300 ppm | PH= 3.2 | 1-4 mins | |
| 2% NaF gel | 2% NaF compound | ~9,000 ppm F | Ages: 3, 7 ,10 or 11, 13 Expected caries reductions = 20-50% | 4 mins | Knutson |
| Sodium fluoride gel/foam | ~0.9% F | ~9,040 ppm F | |||
| SnF₂ (Stannous Fluoride) | 8% SnF₂ solution | ~19,400 ppm F⁻ | Acidic Staining Freshly prepared before use ( Ph 2.5 ) | ||
| Brudevold | 2% NaF + 0.1% 0.1 M orthophosphoric acid (H₃PO₄) | ~9,000 ppm F |
| 2% NaF | 8% SnF₂ | 1.23% APF | |
|---|---|---|---|
| F⁻ | ~9,000 ppm | ~19,400 ppm | 12,300 ppm |
| Form | Solution | Solution | Gel/foam |
| Teeth cleaned first? | Yes | Yes | Usually yes |
| Isolation | Cotton rolls | Cotton rolls | Tray/isolation as needed |
| Application method | Cotton applicator/direct | Cotton applicator/direct | Tray |
| Classic contact/application time | ~4 min | ~4 min | ~4 min |
| Classic frequency | 4 × 1 week apart | 4 × 1 week apart | Historically repeated; modern use generally risk-based |
| Fresh preparation? | No | Yes — classic solution | No |
| pH | Neutral | Acidic/slightly acidic | ~3 |
| Young children | Less convenient | Less convenient | ⚠️ Swallowing concern |
| Main modern professional alternative | — | — | Varnish often preferred |
FLUORIDE VARNISH
| Varnish | Concentration |
|---|---|
| 5% NaF varnish | 2.26% fluoride ion |
| 5% NaF varnish | 22,600 ppm F |
| Difluorosilane varnish | 0.1% F = 1,000 ppm F |
| Fluor Protector | 0.70 % |
A typical varnish application uses only 0.2–0.5 mL, delivering approximately 5–11 mg fluoride ion.
SILVER DIAMINE FLUORIDE — SDF
| Product | Concentration |
|---|---|
| 38% SDF solution | ~5–6% fluoride ion |
| Fluoride concentration | roughly 50,000–60,000 ppm F |
Nalgonda technique
is a community-level and domestic defluoridation method developed in 1974 by the National Environmental Engineering Research Institute (NEERI) in India (Nagpur) . It is designed to remove excessive fluoride from drinking water in low-resource settings.
• Chemical Reagents Used:
1. Aluminium salts (Alum / Aluminium sulphate): Responsible for binding and removing fluoride ions.
2. Lime (Ca(OH2) or CaO): Added to adjust pH, accelerate settling, and form dense flocs.
3. Bleaching powder: Added for disinfection.
Process Steps: Rapid mixing → Flocculation → Sedimentation → Filtration → Disinfection.
Mechanism: Flocculation and precipitation complexation. Alum forms insoluble polyhydroxy aluminum complexes that adsorb fluoride ions, which then settle out of solution during sedimentation.
Advantages: Economical, simple to operate, uses readily available chemicals, and requires minimal energy or skilled labor.