Fluoridation

Understanding Fluoridation

  • Fluoridation is the method of adjusting fluoride concentration into public water supplies to help prevent tooth decay.
  • It works by supplying fluoride ions, denoted F-, to be incorporated into tooth enamel which increases the resistance to acid dissolution caused by bacterial metablolism in the mouth.

Fluoride and Tooth Decay

  • The mechanism of fluoridation in tooth decay prevention involves the reaction of the fluoride ions with hydroxyapatite (the main component of tooth enamel) to form a more acid-resistant material called fluorapatite.
  • The overall reaction can be written as: Ca10(PO4)6OH2 + 2F- → Ca10(PO4)6F2 + 2OH-
  • This reduction of tooth enamel dissolution results in a decay rate decrease of approximately 40% in children, a context where fluoride is widely considered beneficial.

The Benefits of Fluoridation

  • Fluoridation involves very small costs per person and the beneficial effect is had simply by drinking and preparing food with normal tap water, making it highly beneficial and cost-effective.
  • Evidence reports a decrease in occurrences of tooth cavities in areas where fluoride is increased in the water supply.

Risks and Controversy Surrounding Fluoridation

  • While generally seen as overall beneficial, there are potential risks associated with water fluoridation including dental fluorosis, a cosmetic condition caused by overexposure to fluoride causing discoloration of teeth.
  • Overexposure to fluoride, often from ingesting toothpaste or mouth rinse, can also lead to skeletal fluorosis which affects the bones and joints.
  • Ethical considerations are also raised in terms of public consent, as fluoridation is a form of mass medication which not everyone might agree with.

The Fluoridation Process

  • The process typically involves the addition of one of three compounds: sodium fluoride, flurosilicic acid or sodium fluorosilicate.
  • They are cheap, easy to handle, provide an ideal form of fluoride and do not affect the water’s taste or smell.
  • The process is carefully monitored and controlled to keep the fluoride levels within the recommended range. This is usually between 0.7 to 1.3 parts per million (ppm) in many countries.