INTRODUCTION TO FLUORIDES Index History of Fluoridation Fluorides

INTRODUCTION TO FLUORIDES

Index: ® ® History of Fluoridation Fluorides (F) in the Environment ® Fluorides in Food ® Absorption and Excretion of Fluorides ® Fluorides in mineralized tissues

HISTORY OF FLUORIDATION

® 1901 – Dr. Frederick Mc. Kay → Colorado Springs – permanent stains on teeth → called “Colorado Stain” by the local inhabitants – “Mottled Enamel”

® 1905 – Mc. Kay → St. Louis ® 1908 – Mc. Kay presented a case at the annual meeting of the State Dental Association, Boulder ® 1909 – GV Black → Colorado Springs

1916 – Dr. GV Black → histological findings were published – Mc. Kay → caries experience was no higher in mottled teeth

1918 – Britton → shallow wells to deep wells in 1898; those born after 1898 had enamel mottling Similar observations in Oakley, Idaho and in Bauxite, Arkansas Mc. Kay concluded that some mysterious element present in water was responsible for the mottling.

1931 – Mr. HV Churchill (chief chemist) – spectrographic analysis of Bauxite water – F concentration = 13. 7 ppm – water samples from other areas also indicated high levels of F – Fluoride = “mysterious factor”

1931 – Dr. H. Trendley Dean appointed to pursue research on mottled enamel

Shoe Leather Epidemiology / Survey – to find the extent of geographical distribution of mottled enamel in the USA

1. A high concentration of F in water is directly related to the severity of enamel mottling 2. No mottling → 1 ppm F in water 3. Dull, chalky white appearance → 2. 5 - 3 ppm 4. Enamel mottling → F > 3 ppm 5. Mottling with discrete pitting → 4 ppm

1938 – Dean formulated a hypothesis that 1 ppm would not cause fluorosis – undertook “ 21 CITIES STUDY” to test this hypothesis

DEAN’S 21 CITIES STUDY Results: --- showed maximum reduction in caries experience at 1 ppm F in the drinking water

--- at 1 ppm, F caused only ‘the mildest forms of dental fluorosis of no aesthetic significance’ --- as F concentration increased above 1 ppm, there was very slight reduction in dental caries experience but dental fluorosis increased

1942 – Dean et al – 1 ppm F in drinking water → 60% reduction in caries experience 1945 – World’s 1 st artificial fluoridation plant at Grand Rapids, USA

Fluorine ® Halogen Family ® At. No. – 9; At. Wt. – 19 ® most reactive of all the elements; therefore, rarely found in its free / elemental state

FLUORIDES IN FOOD Fish & tea ---- high amounts of F Fish ---- 0. 5 mg / day

ABSORPTION OF FLUORIDES main route of absorption → the gastrointestinal tract EXCRETION OF FLUORIDES via the kidneys - major route for F removal from the body

FLUORIDES IN MINERALIZED TISSUES 99% F is stored in the hard tissues of the body -- skeleton & teeth

FLUORIDES IN SOFT TISSUES ® more in kidney