Fluoride Therapy

Fluoride therapy is widely used to prevent dental caries. Evidence have shown that a constantly maintained low level of fluoride in oral environment is most effective in caries prevention against the earlier popular belief of being it most beneficial against caries during pre-eruptive forming enamel.

Dietary Fluoride supplementation Schedule

American academy of Paediatric Dentistry & American Dental Associations Council on Dental Therapeutics recommend the following regimen for fluoride supplement for an individual having insufficient daily fluoride intake:


Less than 0.3 ppm F 0.3-0.6 ppm F More than 0.6 ppm F

Birth- 6 mos




6 months-3 yrs.

0.25 mg



3 yrs.-6 yrs.

0.5 mg

0.25 mg


6 yrs. to at least 16 yrs. 1.0 mg 0.5 mg


Evaluate fluoride exposer before prescribing fluoride therapy. Document the patient’s fluoride exposer in the record and review at periodic visits. Have a water analysis done prior to issuing supplemental fluoride.

Point of use, water conditioning (filtration system significantly reduce fluoride content. Activated carbon filters reduce fluoride concentration by 81%. Bottled water can have variable fluoride concentrations.

Preschool children require supervision during tooth brushing. No more than a pea size amount of tooth paste should be used, avoid swallowing of the pastes & rinse after brushing.

Fluoride mouth rinses containing 0.05% or 0.2% should not be used by children under the age of six years or those who are unable to adequately expectorate.

Supervise professionally applied topical fluoride treatments. Use 5-10 ml of fluoride gel in well fitting brays, ham the patient lean forward in the dental chair, admonish not to swallow, and use a saliva ejector positioned between trays.

Fluoride Toxicity:

Chronic Toxicity (results in fluorosis)

Dean’s Classification 0-4 scale

  • 0-none
  • 1-very mild
  • 2-mild
  • 3-moderate
  • 4-severe
  • 59% of population at optimal population level will exhibit no flourosis
  • Very mild 7.4 % of population at optimal dose.
  • (mild) greater than 25%, less than 50% of surface with opaque defect (greater than 1.2 ppm)
  • (Moderate) brown stains present (greater than 2 ppm).
  • (Severe) pitting and attrition problems (greater them 2-3 ppm)

Flourosis occurs during maturation process. For incisors, age 2-3 yrs is the critical period.

Acute Toxicity

CLD (certain lethal dose 32-64 mg/kg body wt in one source,71-140 mf/kg in another source. A death has been reported at 17 mg/kg.

PTD (Probable Toxic Dose) 5mg/kg i.e.50 mg for a 10 kg 2 yrs old.

STD (Safely Tolerated Dose) 8-16 mg/kg

Toxicity at low doses is due to gastric irritation.

Hypocalcaemia and hyperkalemia at high doses leads to cardiovascular collapse and death.

Treatment of Overdose

  • Less than 5 mg/kg-oral calcium (milk) and observe
  • More than 5 mg but less than 15 mg/kg- induce vomiting, oral calcium (milk, calcium gluconate, calcium lactate, admit to hospital
  • More than 15 mg/kg- admit to hospital immediately, induce vomiting, monitor cardiac function, 10% calcium gluconate solution IV and monitor electrolytes.



  1. Nausea
  2. Vomiting
  3. Hyper salivation
  4. Abdominal pain
  5. Diarrhoea



  1. Convulsions
  2. Cardiac arrhythemia
  3. Comatose
  • Patients become hypocalcaemic due to Ca binding with fluoride.

Calculating mg Fluoride in Compound

Ist step: Find % F in compound

Name Molecular weight ratio



1/2.2 or 1/2


1/4.1 or 1/4

MFP-sodium Mono fluoro Phosphate

1/7.6 or 1/8

Multiply % compound by molecular weight ratio= % F


2nd Step: Express % Fluoride in compound in mg F/ml

By definition % solution is gram/100 ml.

Gram/100 ml=1000mg/100 ml=10 mg/ml

Multiply step 1 by 10 = mgF/ml

3rd Step: Multiply step 2 by ml ingested to get mg F ingested

  •  23% APF x 1 = 1.23% F x 10 = 12.3 mg F / ml
  • 2% NaF x 1/2 = 0.1 x10 = 1 mg F / ml
  • 2% NaF x 1/2 = 1 x 10 =10 mg F / ml
  • 4 % SnF2 x ¼ = 0.1 x 10 mg = 1 mg F / ml
  • 10% SnF2 x 1/4 = 2.5% x 10 =25 mg F / ml

Compare with CLD and STD for weight of individual


Decrease in caries activity

  • Primary-40%
  • Secondary- 50-60%


  • Decreases enamel solubility.
  • Improves enamel crystalinity.
  • Promotes re mineralisation.
  • Decreases free surface energy of bacteria so it cannot stick on tooth.
  • Bactericidal or bacteriostatic
  • Causes developing crystal to get bigger and less soluble


  • Home use in trays, topical
  • H2O supply
  • Systemic also topical when chewing tablets
  • High frequency low dose is effective


  • Efficacy due to physical obstruction of pit & fissures.
  • May be used over sites with incipient and active caries.
  • Effective for primary teeth.
  • Fluoride releasing sealants.
  • Sealant failures occur during first year, check closely and repair.
  • Dentin bonding agent improves sealant bond wet environment.
  • Timing: Increase failure (54%) with occlusal gingival tags.

Fluoride mouth rinses

Reduce caries by 20-50 %. Weekly 0.2% NaF and daily 0.05% NaF rinses were considered to be ideal public health measure.

Daily rinses

  • 0.02% acidulated phosphated fluoride.
  • NaF (100 ppm).
  • Partly acidulated solution of 0.04% NaF (200 ppm).

Weekly or fortnightly rinses

  • 0.2% NaF (1000 ppm).

Indications :

  • Patients who are undergoing orthodontics treatment.
  • Post-irradiation xerostomia Sufferers.
  • Children unable to perform adequate tooth brushing.


  • Non recommended for preschool aged children.

Fluoride varnishes:

  • Reduction in caries rate-30 %


  • Hypersensitive areas.
  • Newly erupted tooth.
  • Arresting early caries.


  • is an alcoholic solution of natural varnishes.
  • contains 50 mg NaF/ml (2.5%=25000 ppm F)

Fluor Protector

  • A silane fluoride varnish in a poly polyurathane lacquer.
  • Contains lower concentration of fluoride 0.8%.

With such highly concentrated fluoride products, great care must be taken to avoid overuse & ingestion. They should not be used before the eruption of permanent incisors.


  • before fluoride application is not usually needed.
  • may acts as reservoir of fluoride.

Concentrated fluoride gels and solutions:

APF (Acidulated Phosphate Fluorides – 1.23 % F ie 12,300 ppm F

  • AFP gels are mainly used for the prevention of caries development.
  • Used for professional application.
  • Has a mixture of NaF, HF and orthophosphate acid.
  • Should be limited for professional use.
  • Should not be dispensed for home use.
  • Incorporation of a water soluble polymer i.e. Sodium carboxymethyl cellulose into APF produces a viscous solution that improves the ease of application using custom made trays.
  • Thixotropic gels in tray flow under pressure, so facilitating the penetration of the gel between teeth.

Neutral NaF 2.2%

  • Preferred in cases of erosion, exposed dentin ‘Calais dentin Or where very porous enamel exist.
  • Chemically very Stable, has an acceptable taste, nonirritating to the gingival docs not discolors teeth, composite or porcelain restorations as APF or stannous fluoride may.

Stannous fluoride Sn F2

  • 10%.Sn F2 is used to target local at risk surfaces of teeth such as deep fissures & pits.
  • Rapid penetration of tin and fluoride into enamel and the formation of a highly insoluble tin-fluorophosphates complex coating on the enamel are the main mechanisms of its action.
  • Often produces discoloration of teeth and staining on margins of restorations-particularly in hypocalcified areas.
  • 0.4% SF2 get in a methylcellulose and glycerin base has proved effective in arresting root caries. It has been incorporated into a synthetic Saliva solution to reduce caries in post-irradiation cancer patient.

Systemic fluorides

  • Fluoride supplement (tablets & drops have limited application as a public health measure but may be of benefit to individuals with a high caries brisk.
  • Beneficial in non-fluoridated communities. Benefit is small.
  • Overzealous use –Fluorosis.
  • Fluoride tablets should be chewed rather than swallowed-both topical & systemic benefit.
  • In the Period between 2-3 years maxillary incisor teeth are most susceptible to fluorosis.

Daily F supplement doses schedule for persons concerned at particularly high caries risk


Age interval

F level in water <0.3 mg/L

F level in water 0.3-0.5 mg/L

6 monthts-4 yrs.

0.25 mg


4-8 yrs.

0.5 mg

0.25 mg

> 8 yrs.

1.0 mg

0.5 mg

*All supplement should be formulated as lozenges,

*A person whose daily dose is 0.5 mg should consume 0.25 mg tablet two times daily.

Take the Mock Test 15: Fluoride Therapy by clicking HERE.


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