Transcript Epistimology - University of Pittsburgh

Fluoridation:
Turning the Tide on Dental Decay
Robert Weyant, DMD DrPH
Department of Dental Public Health
and Information Management
University of Pittsburgh
Fluoridation:
controlled addition of fluoride compound to a public water supply in
order to bring its fluoride concentration to optimal
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One of the CDC’s Top 10 major public
health achievements in 20th c.
Major factor responsible for the decline
in dental caries (tooth decay).
Classic example of clinical observation
leading to epidemiologic investigation
and community-based public health
intervention.
The fluoride story 1901 - 1950
Caries: Case Definition
coronal caries
Diet
Bacterial Acids
Salivary Minerals
Rx
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Dental Caries is the localized destruction
of dental hard tissues by acidic byproducts from bacterial fermentation of
dietary carbohydrates.
The disease process is initiated within
the bacterial biofilm.
No global consensus on staging.
DMFT index = severity.
root caries
Dental Caries
Early childhood caries
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Dental caries most
common chronic childhood
disease.
Over 50% of 5- to 9-yearold children have at least
one cavity or filling.
Decay prevalence is 78%
in 17-year-olds.
Root Caries
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Common infectious disease
in older adults.
Poor rates of diagnosis and
treatment.
More retained teeth - more
“at risk” teeth.
Strong link with xerostomia
Fluoride effective in
prevention.
Root Caries Prevalence by Age
Caries
Process
Nutrition
(baby bottles, sodas,
sugars & carbohydrates)
Caries
Oral Hygiene
(tooth brushing,
fluoride use, flossing)
Patient’s Knowledge,
Attitudes, Behavior
(dental fear, mistrust, competing
priorities, lack of OH knowledge,
cultural expectations)
Access to and Use of
Professional Dental Care
(regular cleanings,
restorative care)
(i.e., tooth decay,
cavities)
Caries
Process
Substance Abuse
(tobacco, alcohol,
methamphetamine)
Co-morbid Health Conditions
(xerostomic medications,
compromised immunity, chronic
inflammation)
Family Functioning
(parental engagement, limitsetting, attachment,
communication, support from
extended family, conflict, abuse
and neglect)
Nutrition
(baby bottles, sodas,
sugars & carbohydrates)
Caries
“Built Environments”
Oral Hygiene
(tooth brushing,
fluoride use, flossing)
cavities)
(proximity to grocery stores and
dental clinics, access to public
transportation)
Patient’s Knowledge,
Attitudes, Behavior
(i.e., tooth decay,
Access to and Use of Professional
Dental Care
(regular cleanings,
restorative care)
(dental fear, mistrust, competing
priorities, lack of OH knowledge,
cultural expectations)
Screening, Brief Intervention
& Referral to Treatment
(substance abuse, injury risk behavior,
Genetics
HIV, diabetes, obesity)
Dental Caries: Secular Changes
• A big problem in need of a
solution.
• Steady increase from 1000
AD to mid-20th cent.
• Major cause of death
1600s-1800s.
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Caries: The Problem in the first half
of the 20th Cent.
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typical school child developed 3-4 new
carious lesions each year.
commonplace for folks to get dentures as
HS graduation presents or wedding gifts.
Caries associated facial cellulitis
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WW II (Standard: 6 opposing teeth)
• ~1 million draftees couldn’t meet standard.
• 40% of draftees required immediate Tx.
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Fluoridation History
Fredrick McKay, DDS.
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1901, Graduates Penn,
moves to Colorado Springs.
Notices brown staining –
later called “Colorado Brown
Stain”.
Launches into field epid.
activities.
GV Black joins the investigation
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1909 Black arrives Colorado Springs.
90% of city’s locally born children had
disorder.
Continued investigation showed:
• “Mottled enamel” was a
developmental defect in tooth. (no
risk of mottling for healthy erupted
teeth).
• Afflicted teeth had no decay…
1920s - A water causation theory
emerged.
Shades of John Snow…
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McKay to Oakley, Idaho.
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McKay to Bauxite, Arkansas.
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Stains occurred when new pipeline build.
A tale of two towns.
1931 ALCOA (H.V. Churchill) joins in and fluoride is
discovered as the causative agent.
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H. Trendley Dean
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1931 begins to study
epid. of F•
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Improves technology of
assay
Creates and index
1933 - Compares
“High” and “Low” Fcommunities.
1939 - Compares
“high” and “low” Fcommunities.
1941- Launches field
investigation – “21
Cities” study.
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Why not add it to the water…
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Gerald Cox (Pitt
faculty)
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Caries reduction ~50%
Fluorosis – 10% Mild to Moderate
1945 - A plan was
developed.
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Short term obsv.
study – health
effects.
Intervention trial.
• Grand Rapids –
Muskegon.
• Newburgh –
Kinston.
• Branford - Sarnia.
• Evanston – Oak
Park.
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Fluoride growth in US
and Global Status
Current fluoridation status of US public water systems
59% of US population receives fluoridated water
Percent public water supply 10
highest and 10 lowest states.
88% US on public
water supply
F- Biological Mechanisms
Post Eruptive (ongoing, daily)
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Remineralizes enamel.
Inhibits glycolysis.
Pre Eruptive (early childhood)
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Some reduction of enamel
solubility.
Water Fluoridation
Toothpaste
Rinses
Post-natal tablets
and drops
Water fluoridation
Fluoridation
Process and Practices
Dosage
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Air Temperature Dependent
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Range 0.7 – 1.2 ppm.
Maximum Contamination Level (EPA)
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4 ppm.
Fluoride and Caries: 1960-2010
Fluoride is everywhere
Water
Toothpaste (1960s)
Processed foods
Soft drinks
Mouthrinses
Varnishes
Tablets
Caries is different
• Less prevalent
• Less severe
• Slower
• Concentrating in
fewer/poor people
Decrease of about 70-80% in caries
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DMFS
Age specific caries rates
1971-1991
Mean Number of Missing Teeth for 12 year-old
Children by Year of Survey
Caries Trends (developed nations)
Caries in 12 y/o
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Historically - disease
of high-income
countries (and high
income individuals).
Recent changes (late
20th c) showed
dramatic decreases
in caries prevalence
in many developed
nations.
Caries Trends (developing nations)
Caries in 12 y/o
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Trend is less clear in
“middle” and “low”
income nations.
Function of diet,
health infrastructure,
and economy.
Changes in Coronal Caries:
Post Fluoride
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Disease is now on occlusal
surfaces (>80%).
Disease is concentrating in
poor.
• 25% of population has 75%
of disease.
Slower progression.
Percentage of Children Aged 2-4 years Who Have
Ever Had Tooth Decay
Family Income
Source: NHANES III, 1988-94
Fluoride and Politics
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Falls under “police powers” of the states.
Mandatory in 8 states.
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Most states use local control at community level.
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Connecticut (1965), Georgia (1973), Illinois (1967), Michigan (1968),
Minnesota (1967), Nebraska (1973), Ohio (1969), and South Dakota
(1969).
Historically local referenda pass only 25% of the time.
21 states meet HP 2010 of at least 75% of pop. with Fwater.
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Antifluoridationists
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Extra-scientific selforganizing group not
interested in the
traditional scientific
process, but goes
around it directly to the
public to bring up
sensational,
unsubstantiated claims.
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Cancer
Downs Syndrome
Kidney Problems
IQ problems
Dementia
All cause mortality
Congenital
Malformations
Systematic Reviews of Safety and
Efficacy
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BMJ (2000)
Australian MRC (2007)
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Water fluoridation
beneficial in reducing
decay.
Insufficient evidence of
adverse effects other
than fluorosis.
Benefits:
Prevalence
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214 studies.
Decrease 14.6%
(range -5% to 64%).
Benefits: Severity
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Mean difference DMFT
2.25 (range 0.5 to 4.4).
Harm: Fluorosis
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Dose dependent
association.
Harm:
Bone Fracture
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Studies of >10 yrs =
fluoride protective.
Harm: Cancer
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26 studies
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24 no association
1 positive (more cancer)
1 negative (less cancer)
Bassin Study
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Osteosarcoma
• 5.6 / 1 million (incidence)
• males 2.0 > females
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Finding
• OR 5.16 (1.7 – 16.2) (males at
age 7)
• No association for females
Age-specific Fluoride Exposure in Drinking Water and
Osteosarcoma (United States) (Bassin et al., 2006)
Harm: Toxicity
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Acute fatal poisoning (adults).
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Acute fatal poisoning (10 kg child).
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2.5 to 5 grams in 2 to 4 hours.
320 mg in 2 to 4 hours.
Acute fatal poisoning in 3 yo child, 435 mg in approx.
3 hours.
Short-term nausea in primary school following
ingestion of 93 to 375 ppm H2O- symptoms appeared
within 30 minutes,
CDC
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Continues to recommend.
Effectiveness now 15-20%.
Still most cost-effective
approach.
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$0.50/person/yr.
Avg savings = $38.00/yr.
Reduces disparity.
Fluorosis 7-16%.
The End
Questions?
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