Course Review- L5 Flashcards
Hg=
mercury
T/F: Mercury is a man made element
F- naturally occurring
Organic form of mercury:
methyl mercury
Elemental form of mercury:
Hg^0
Inorganic Hg salts:
Hg^+1 and Hg^+2
What is the most toxic form of mercury?
Organic: Methyl mercury
The most toxic form of mercury (methyl mercury- organic) can be found in:
fungicides, fish, water
T/F: Methyl mercury is 95% GI absorbed
true
Methyl mercury is _____ soluble and is ____ distributed throughout the body tissues
lipid; uniformly
Methyl mercury toxicity results in:
neurological damage
Most large scale mercury poisonings are due to:
organic mercury
Organic mercury =
methyl mercury
What form of mercury is a liquid metal?
elemental mercury
Describe the distribution of elemental mercury (Liquid Metal):
Vaporizes easily, passes through membranes, skin and blood brain barrier
T/F: elemental mercury is readily absorbed orally and throughout the GI tract
false- little or no oral or GI absorption
T/F: Lungs will NOT absorb vapor elemental mercury:
False- lungs ABSORB vapor of elemental mercury
What happens if you inhale elemental mercury vapor? (Liquid Metal)
can have toxic CNS effects with breathing lots of vapor
When might there be risks for inhalation of elemental mercury (liquid mercury) vapor?
In occupational setting or mercury spills in poorly ventilated area
What type of mercury is used in dental amalgam?
ELEMENTAL mercury
What type of mercury are found in compounds used extensively in industry?
inorganic mercury salts
List some inorganic mercury salts (4):
- mercuric chloride
- bromide
- sulfate
- nitrate
What is the LEAST toxic form of mercury?
inorganic mercury salts
Describe the GI absorption of inorganic mercury salts:
poor absorption
Describe the GI absorption of the following forms of mercury:
- Methyl mercury (natural)
- Elemental mercury (Liquid Metal)
- Inorganic mercury salts
- 95% GI absorption
- NO GI absorption
- Poor GI absorption
What happens with high levels of inorganic mercury salts?
mercuric ions concentrate in kidneys, acute toxicity, and renal necrosis
- note this is still the least toxic form of mercury
T/F: Inorganic mercury salts are water soluble and can lead to environmental water pollution
True
Amalgam resotrations have been used for
150 years
List some benefits of amalgam restorations:
- affordable
- durable
- safe
- longevity
T/F: Up to 75% of amalgam restorations last for 15+ years
false- 80%
T/F: With amalgam restorations, Hg does not enter pulp, bone or gingiva
true
When is there risk for Hg vapor release with amalgam restorations?
- mixing/insertion
- polishing
- removal
T/F:
Small amounts of Hg vapor are absorbed by the lungs, concentrated in the liver, and excreted through feces. Mercury levels are best measured through feces.
Both false; small of amounts of Hg vapor are absorbed by the LUNGS, concentrated in the KIDNEYS, and excreted through URINE. Mercury levels are best measured through URINE
List the percentages of overall envrionmental mercury release:
____ fuel combustion
____ waste combustion
____ manufacturers and consumers
_____ from dentistry
53% fuel combustion
34% waste combustion
13% manufacturers and consumers
LESS THAN 1% from dentistry
To control dental Hg release:
amalgam waste must be handled correctly
List what comprises the amalgam waste capture devices:
- chair side trap
- vacuum pump filter
- amalgam separator
What is contact amalgam?
amalgam that has contacted the patient
What are some forms of contact amalgam?
- carving scrap
- extracted teeth
- amalgam in traps, filters, or screens
Non-contact amalgam =
leftover mix
