Course Review- L5 Flashcards
Hg
Mercurcy
T/F: Mercury is a man-made element
False- naturally occuring
Organic form of mercury:
Methyl mercury
Elemental form of mercury:
Hg^0
Inorganic Hg salts:
Hg^+1
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 barriers
T/F: Elemental mercury is readily absorbed orally and throughout the GI tract
False- little to no oral or GI absorption
T/F: Lungs will NOT absorb elemental mercury vapor
False- Lungs ABSORB elemental mercury vapor
What happens if you inhale elemental mercury vapor (liquid metal):
Can have toxic CNS effects with breathing lots of vapor
When might there be risk for inhalation of elemental mercury vapor?
In occupational setting or mercury spills in poorly ventilated areas
What type of mercury is used in dental amalgam?
ELEMENTAL MERCURY
What types 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
- 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 pollution
True
Amalgam restorations have been used for:
150 years
List some benefits of amalgam restorations:
- affordable
- durable
- safe
- longevity
Up to 75% of amalgam restorations last for 15+ years
False- 80%
T/F: With amalgam restorations, the Hg will not enter the pulp, bone or gingiva
True
When is the risk for Hg vapor release with amalgam restorations?
- mixing/insertion
- polishing & removal (due to heat)
T/F:
Small amounts of Hg vapor are absorbed by the lungs, concentrated in the liver, and extracted through feces
Mercury levels are best measured through feces
Both statements false;
small 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 environmental mercury release:
____ fuel combustion
___ waste combustion
___ manufacturers & consumers
____ from dentistry
53% fuel combustion
34% waste combustion
13% manufacturers & consumers
LESS THAN 1% from dentistry
To control dental Hg release:
Amalgam waste must be handled correctly
List what comprises the amalgam waste capture device:
- chairside trap
- vaccum 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:
Left over mix
