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Salt Fluoridation

Salt Fluoridation

Fluorides

Salt fluoridation is the controlled addition of fluoride, usually as sodium or potassium fluoride, during the manufacture of salt for consumption.

  • Recommended concentration : 250 mg of fluoride per kg salt.

  • Methods of salt fluoridation:

    • Spraying concentrated solution of NaF or KF on salt on a conveyor belt, or
    • Mixing premixed granules added to the salt.

History & Use

Fluoridated salt as a means of preventing caries was first used in 1955 in Switzerland by Wespi, a gynaecologist who started adding of fluoride to salt.

  • The addition of fluoride to salt for human consumption was officially authorised in 1980-82.
  • The Swiss studies began with salt fluoridated to 90 mgF/kg salt (or 90 ppm). It was later increased to the current standard 250 mgF/kg.
  • The most appropriate concentration have been estimated from studies of 24 hours urinary fluoride excretion.
  • Countries using salt fluoridation : Germany, Mexico, Colombia, Peru, Cuba, Hungary, Spain, France, Costa Rica, Jamaica, etc.

Advantages

  • The caries preventive action of fluoridated salt is substantial, approaching that of fluoridated water. As a dietary vehicle for fluoride, domestic salt is the second best to water fluoridation.
  • Caries reduction is about 40-50%.
  • Low cost.
  • Wide coverage.
  • Requires little conscious action by the individual.
  • Freedom of choice available for consumers as both fluoridated and non-fluoridated salt is available.
  • It is safe as toxic levels of salt are reached long before that of contained fluoride.
  • No supervised water works or water distribution system is necessary, making it a practical method for many countries.
  • Minimum possibility of fluorosis as children use very little salt.

Disadvantages

  • Community wide caries-preventive impact is clearly related to the extent of public acceptance.
  • Needs to be accompanied by public education and promotion.
  • Salt intake varies among individuals, hence, control on individual consumption is not as precise as with water fluoridation.
  • There are international efforts to reduce sodium intake to help control hypertension.
  • Consumption of fluoridated salt is lowest during early life when the need for fluoride is the maximum.

WHO criteria for use of salt fluoridation

  • It should be used where water fluoridation is not possible.
  • Where there are low levels of fluoride in water.
  • Where there is not the political will to introduce water fluoridation.
  • Where there is a centralised salt production system with strong technical support.
  • Appropriate labelling of the salt packages is essential.

References

  • C. M. Marya - A Textbook of Public Health Dentistry, Jaypee Brothers Medical Publishers (P) Ltd (2011). https://amzn.to/3SHP36G
  • S. S. Hiremath - Textbook of Public Health Dentistry, Elsevier India (2016). https://amzn.to/49mh2jw
  • Marthaler TM. Salt fluoridation and oral health. Acta Med Acad. 2013 Nov;42(2):140-55. doi: 10.5644/ama2006-124.82. PMID: 24308394.
  • The image used is licensed under Creative Commons Attribution-Share Alike 4.0 International license. (Source : Wikimedia Commons, Author : Poyraz 72).

*This article is an excerpt from the above mentioned books and Medical Sutras does not make any ownership and affiliation claims.