Mercury in Dental Amalgam

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Mercury in Dental Amalgam

• What mercury? Where?
• Who is exposed?
• Animal studies, of sheep and monkeys
• Human studies, reports and possible links to
  Alzheimers
• Children and Moms
• Properly informed / low-income / cost
• Waste removal / water / environment
• FDA / WHO / USPHS / EPA / OES
• Should we be concerned?

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Mercury in Dental Amalgam

• Commonly known as silver fillings
• Center of Disease Control removal but they still
  remain in dental amalgam
• 40-54 mercury, 25 silver, 25-35 mixture of
  copper, zinc, and tin
• Amount per amalgam 327-982mg
• American Dental Association(ADA) main ingredient
  but called silver fillings
• 31 metric tons of mercury purchased for dental
  services in 1996
• 1998, 83 of 1069 dentists surveyed use amalgam
  fillings

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Who is exposed?

• If you have a silver filling you are exposed to
  mercury daily, levels depend on the number of
  amalgams you have, general public range 0-5mgHg
• Dentists, their assistance, public in dental
  office, with or without their our fillings
• Unborn fetus of mothers with amalgam fillings
• Newborns breast feeding from mother
  with amalgam fillings
• Public from improper removal
  and disposal of toxic mercury
  waste (discussed in waste
  removal)

4
Exposure continue

• International Academy of Oral Medicine and
  Toxicology
• The smoking tooth by Roger Eichmann
• 25 year old silver filling of extracted tooth
• Shadow seen is poison gas of mercury vapor once
  immersed in 110 water
• 1,000 times higher than EPA
  allows in air we breath
• Coffee, tea, or simply and
  commonly from grinding
  your teeth

5
Exposure continue

• Dentists - higher baseline urinary Hg levels
  10.9 over 30mg per liter 1.3 over 100mg per
  liter (dental students)
• Effects, neuropsychological, neurobehavioral
  changes, attention impairment, motor control
  deficits, suicide rates high
• Female assistance fertility rate of 63
• Fetus newborn, Hg across placenta and into
  breast milk, risk to developing brain
• Autopsy of human stillbirths postnatal death,
  correlates Hg concentrations in KID, LIV, and
  cerebral cortex to moms amalgam scores

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Animal Studies (sheep monkey)

• International Academy of Oral Medicine and
  Toxicology
• Placed amalgam fillings into sheep for 30 days
  followed by full body gamma ray scan
• Results accumulation of mercury in jaw,
  stomach, liver, kidneys, mercury transferred
  immediately to fetus body
• Dental establishment argue sheep chew to much

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Full body gamma ray scan of sheep
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Monkey

• Since sheep chew to much the study was again done
  on a monkey
• The results were the same mercury accumulation in
  the jaw, stomach, liver, and kidneys
• Since testing radioactive Hg, diet exposure was
  addressed

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Human studies

• Not enough studies on low chronic exposure
• Recent studies suggest Hg is a multipotent
  cytotoxin, effecting primary processes of the
  cell. Creating many possible side effects
• Links to impaired CNS function, kidney function,
  decrease in immune system, foetal development
  impairment (Nervous system development)

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Human studies

• Boyd Haley, protein biochemist Calgary Canada
• Effects on neurons in tissue cultures when
  exposed to mercury
• Lead and aluminum tested and no effects, cadium
  showed a small effect
• GTP molecule blocked by mercury preventing
  ß-subunit from binding (similar tubulin synthesis
  defect in Alzheimers disease)

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Boyd Haley biochemist, tubulin synthesis defect,
ß-subunit unable to bind to GTP molecule blocked
by low concentration of mercury 107 M range
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Children and Moms

• Sheep study, showed fetus concentration of Hg in
  liver and pituitary gland, primary site of
  accumulation after birth was in the kidneys
• Drasch study on autopsy of stillbirths, showed Hg
  concentration in kidneys, liver, and cerebral
  cortex based on moms amalgam scores

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Children and Moms

• Over 180 million people in U.S. with amalgam
  fillings
• Though not banned, encouraged to avoid amalgams
  in children and Pregnant women
• Possible developmental deficits, some believe
  linked to autism
• New materials , fluoride, dental sealants
  and preventative steps help decrease
  
  cavities in children

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Properly informed / low-income / cost

• Possible need for formal amalgam education for
  dentist, so that patient could make a informed
  choice
• Cavities filled with amalgam fillings need to
  drill away larger area of healthy tooth, which
  weakens the tooth, leading to more costly dental
  work
• Dentist call them silver fillings, with out
  informing the risk of mercury vapor exposure
• New material, are available at a greater cost
• Medicaid and basic insurance companies dont
  cover cosmetic work leaving low-income families
  without options even if adverse reaction occurs

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Waste removal / water / environment

• Little thought goes into the waste created from
  amalgam removal or replacements
• EPA prohibits discharge of pollutants including
  Hg into water unless permitted by EPA or state,
  which must still ensure water quality standards
• Study of 878 dentist, 22 report using
  separators, 940.16kg of mercury was removed that
  would have other wise been released into waste
  water
• 2002 estimate release of 170.72gm of Hg per
  dentist daily

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FDA / WHO / USPHS / EPA / OES

• FDA and USPHS - there is no scientific evidence
  that amalgams cause harm except in rare cases
• WHO - in 1991 amalgam predominant source of human
  exposure to mercury, in 1997 amalgams are safe
  and cost-effective
• EPA - estimated 0.7 tons of Hg per year emitted
  into environment from dental services
• OES - Occupational Exposure Standards
  (Scotland,UK) in 68 dental offices above safety
  guidelines

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• In 1991 WHO acknowledged predominant human
  exposure from fillings, average daily dose is 17
  micrograms /HG.

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Should we be concerned?

• Knowing that mercury is toxic we should be
  concerned
• Still not banned and direct exposure from amalgam
  fillings and indirect from water waste places
  everyone at risk
• As awareness increases amalgam fillings are
  decreasing in children yet they are still used
  and developmental effects need attention
• More studies are needed that focus on low level
  chronic exposure to better understand Hg effects

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References

• Retrieved November 8th, 2005 from
  www.blackwellpublishing.com.
• Retrieved November 8t, 2005 from
  http//www.fda.gov/cdrh/consumer/index.html
• Retrieved November 8th, 2005 from
  http//www.bracesinfo.com/insurance/club.htm
• Retrieved November 8th, 2005 from
  http//www.newmoa.org/Newmoa/htdocs/prevention/top
  ichub/nav.cfm?hub103subsec1
• Retrieved November 10, 2005 from
  http//www.ingentaconnect.com/content/urban/441/20
  01/00000204/00000004/art00097

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References

• Hylander, L.D. Lindvall, A., Gahnberg, L. (2005)
  High mercury emission from dental clinics despite
  amalgam separators. Scince Total Environment. 16,
  S-752, 36
• Berlin, M. (overview 1997-2002) Mercury in
  dental-filling materials an updated risk analysis
  in environmental medical terms. The Dental
  Material Commission Care and Consideration
• Luglie, P.F., Campus,G., Chessa,G. Spano, G.
  Capobianco, G., Fadda, G.M., Dessole, S. (2005)
  Effect of amalgam fillings on the mercury
  concentrationin human amniotic fluid. Arch
  Gynecol Obstet. 2,138-42