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:

Age

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

Birth- 6 mos

0

0

0

6 months-3 yrs.

0.25 mg

0

0

3 yrs.-6 yrs.

0.5 mg

0.25 mg

0

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

0

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.

COMMON SIGNS AND SYMPTOMS OF ACUTE FLUORIDE TOXICITY

LOW DOSES

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

HIGH DOSES

3-C’s

  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
APF

1

NaF

1/2.2 or 1/2

SnF2

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

 WATER FLUORIDATION

Decrease in caries activity

  • Primary-40%
  • Secondary- 50-60%

MECHANISM OF ACTION OF FLUORIDE

  • 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

FLUORIDE PROTOCOL

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

SEALANTS:

  • 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.

Contraindications:

  • Non recommended for preschool aged children.

Fluoride varnishes:

  • Reduction in caries rate-30 %

Indications:

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

Duraphat

  • 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.

Prophylaxis:

  • 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

0

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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