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History of Water Fluoridation


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Title: History of Water Fluoridation

History of Water Fluoridation
History of Water Fluoridation
  • Two stories unfolded over more than half a
  • The story of the harmful effects of fluoride in
    large doses
  • The story of dental benefits from small doses

Harmful effects of fluoride
  • The first important mention of the fluorosis
    occurred in 1902 in El Paso County, Colorado By
    Frederick S. McKay.
  • McKay gave systematic attention to the mottling
    and brown staining he found on the teeth of many
    of his patients and hypothesized its due to
    water supply.

Harmful effects of fluoride
Harmful effects of fluoride
  • By 1908 McKay studied enough cases and interested
    enough colleagues to invite Dr. G. V. Black, then
    Dean of Northwestern University Dental School to
    join him in the study.
  • Blacks visit gained national attention to the
    phenomenon and afterwards many cases were
    reported from other parts of the country.
  • The name Colorado brown stain eventually gave
    way to that of mottled enamel and the process
    soon became associated with communal water
    supplies, usually from deep wells deep well

Harmful effects of fluoride
  • In Britton, South Dakota, in 1916 a study
    revealed uniformed mottling of enamel among the
    children brought up in the town since a new deep
    well had been added to the communal water supply
    in 1898.
  • In 1925, citizens of Oakley, Idaho, where
    mottling was prevalent, undertook to test the
    deep well hypothesis by changing from a warm
    spring-water supply (artesian water) to another
    shallower water supply
  • In succeeding years, the children on the new
    water supply developed no mottling, but the
    children brought up on the old supply were not

Harmful effects of fluoride
  • In 1925, McCollum, Bunting and others did
    experiments on rats and found that rats, fed in
    excess of fluoride developed staining in
  • At the time this wasnt connected to stains in
    enamel in humans .

Harmful effects of fluoride
  • Studies initiated in 1928 in Bauxite, Arkansas,
    led to the final discovery that mottled enamel
    was associated with fluoride in water
  • An exceptionally high incidence of mottling
    occurred in this town, and the action upon the
    problem was more far-reaching than usually
    because of presence of a plant of Republic Mining
    and Manufacturing Company, a subsidiary of the
    Aluminum Corporation of America.
  • Samples of Bauxite water eventually came to the
    laboratory of H. V. Churchill, chief chemist for
    Alcoa, who initiated spectrographic study.13.7
    parts per million of fluoride were found in the
    Bauxite water!
  • McKay was notified in 1931.

Harmful effects of fluoride
  • Following this McKay arranged for reanalysis of
    the water supplies in Britton, South Dakota,
    Oakley, Idaho, and elsewhere.
  • Subsequent rechecking in many parts of the United
    States soon developed a striking correlation
    between mottled enamel and a fluoride content of
    public water ranging from 2 to 13 parts per
  • At the same time Smiths in Arizona and Velu in
    France made similar connection between mottled
    enamel and fluoride, but this didnt spark as
    much interest.

Dental benefits of fluoride
  • The coexistence of low dental caries and mottled
    enamel had excited comment from McKay, even in
    the early years of his investigation.
  • After the discovery that fluoride correlated with
    mottled enamel in 1931, several other
    investigations also noted this inverse relation.

Dental benefits of fluoride
  • Dr. H. Trendley Dean, on duty with the US Public
    Health Service, made a thorough documentation of
    the degree of mottled enamel and degree of caries
    at different concentrations of fluoride.
  • As it became obvious that large reductions in
    caries incidence were associated with the
    occasional appearance of enamel opacities that
    were in no way disfiguring, the term mottled
    enamel gave way to the more exact term dental
  • 1939 Cox and his coworkers suggested that
    supplying optimum amount of fluorine during the
    tooth-forming years could considerably reduce
    dental caries.

Dental benefits of fluoride
  • 1941-42. Dean HT (National Institute of Health)
    reported on examination of 7,257
    continuous-residence white children of 21 cities
    with differing amounts of fluorides in their
    community waters.

Dental benefits of fluoride
Dental benefits of fluoride
Dental benefits of fluoride
  • The studies established
  • Children 12-14 who have continuously, since
    birth, used water with an optimal fluoride
    concentration have, in general about two-thirds
    less dental decay than children who used
    fluoride-free drinking water.
  • Lessened amount of dental caries follows the use
    of a domestic water containing as low as1.0 ppm
    of fluoride.

Three pilot studies (started 1945)
  • Newburgh, New York, with Kingston as a control.
  • Grand Rapids, Michigan, with Muskegon as a
  • Brantford, Ontario.

Newburgh Kingston study
  • 1942 Ast prepared a thesis on the caries-fluorine
    hypothesis in which he suggested a plan to test
    this hypothesis.
  • 1943. A favorable report was made to Edward S.
    Godfrey M.D., then the State Commissioner of
  • Newburgh and Kingston were chosen for the study

Newburgh Kingston study
  • In March, 1944 the City Council of Newburgh
    approved the water fluoridation
  • Following this many complaints were received from
    local citizens in the span of one year
  • Discoloring sauce-pans
  • Digestive disturbances
  • One complaint about water causing a denture to

Newburgh Kingston study
  • But it was not until May 2, 1945 that the water
    was fluoridated!
  • Local paper carried an editorial which pointed
    out to the people how some persons can imagine
    all sorts of disabilities from nonexistent
  • This ended the complaints.

Newburgh Kingston study
  • Dental caries measurements (by one dentist) in
    6-12 year olds for both cities (1944-45)
    demonstrated close comparability
  • Annual clinical examinations in both cities
    (1944-55). Supplemented with roentgenograms
    (1949-50, 53-54, 54-55)
  • Several reports published. All showed
    improvements in Newburgh and lack thereof in

Newburgh Kingston study
Newburgh Kingston study
  • At the same time Pediatrics study was conducted
    in the cities (with Kingston as a control).
  • Annual visits of children to the study clinic.
  • After 10 years of water fluoridation no
    differences of medical significance could be
    found between the two groups of children.

Grand Rapids
  • 1945 Grand Rapids, Mich began water fluoridation
  • Presented findings are from 1950
  • Study compares
  • Grand Rapids, Mich water fluoridation
  • Muskegon, Mich control (similar climate)
  • Aurora, Ill naturally fluoridated water supply
  • Examinations of virtually the entire school
    populations in continuous residence.

Grand Rapids
  • Findings reported in
  • def (decayed, extraction indicated, or filled)
    for deciduous teeth
  • DMF (decayed, missing, or filled) for permanent

Grand Rapids
Grand Rapids
Brantford Sarnia Stratford
  • 1945 Brantford, ON began water fluoridation
  • Final Survey, 1963
  • Study compares
  • Brantford water fluoridation
  • Sarnia negligible amount of fluoride in water
  • Stratford naturally fluoridated water supply
  • Native, Continuously Resident 16-17-Year-Old
    Children were examined (n 356, 482 and 227

Brantford Sarnia Stratford
  • All examinations done by the same examiner
  • Findings are presented in respect to (1) all
    permanent teeth, and (2) permanent upper incisors.

Brantford Sarnia Stratford
  • Indices used to measure caries-prevalence
  • of caries-free children
  • Permanent teeth
  • Upper incisors
  • Tooth mortality rate
  • DMF (decayed, missing, filled)
  • Permanent teeth per child
  • Permanent upper incisors

Brantford Sarnia Stratford
Brantford Sarnia Stratford
Brantford Sarnia Stratford
Brantford Sarnia Stratford
Dental benefits of fluoride
  • The End ?
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