History of Water Fluoridation

1
History of Water Fluoridation
2
History of Water Fluoridation

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

3
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.

4
Harmful effects of fluoride
5
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
  hypothesis

6
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
  cured.

7
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
  incisors.
• At the time this wasnt connected to stains in
  enamel in humans .

8
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.

9
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
  million.
• 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.

10
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.

11
Caries
12
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
  fluorosis.
• 1939 Cox and his coworkers suggested that
  supplying optimum amount of fluorine during the
  tooth-forming years could considerably reduce
  dental caries.

13
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.

14
Dental benefits of fluoride
15
Dental benefits of fluoride
16
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.

17
Three pilot studies (started 1945)

• Newburgh, New York, with Kingston as a control.
• Grand Rapids, Michigan, with Muskegon as a
  control.
• Brantford, Ontario.

18
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
  Health.
• Newburgh and Kingston were chosen for the study

19
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
  crack.

20
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
  causes.
• This ended the complaints.

21
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
  Kingston

22
Newburgh Kingston study
23
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.

24
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.

25
Grand Rapids

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

26
Grand Rapids
27
Grand Rapids
28
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
  respectively).

29
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.

30
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

31
Brantford Sarnia Stratford
32
Brantford Sarnia Stratford
33
Brantford Sarnia Stratford
34
Brantford Sarnia Stratford
35
Dental benefits of fluoride
36

• The End ?