Course Review- L5

Question 1

Hg

Answer 1

Mercurcy

Question 2

T/F: Mercury is a man-made element

Answer 2

False- naturally occuring

Question 3

Organic form of mercury:

Answer 3

Methyl mercury

Question 4

Elemental form of mercury:

Answer 4

Hg^0

Question 5

Inorganic Hg salts:

Answer 5

Hg^+1
Hg^+2

Question 6

What is the most toxic form of mercury?

Answer 6

Organic - methyl mercury

Question 7

The most toxic form of mercury (methyl mercury– organic) can be found in:

Answer 7

Fungicides
Fish
Water

Question 8

T/F: Methyl mercury is 95% GI absorbed

Answer 8

True

Question 9

Methyl mercury is ____ soluble and is ____ distributed throughout the body tissues

Answer 9

Lipid; uniformly

Question 10

Methyl mercury toxicity results in:

Answer 10

Neurological damage

Question 11

Most large scale mercury poisonings are due to:

Answer 11

Organic mercury

Question 12

Organic mercury:

Answer 12

methyl mercury

Question 13

What form of mercury is a liquid metal?

Answer 13

Elemental mercury

Question 14

Describe the distribution of elemental mercury (liquid metal):

Answer 14

-vaporizes easily, passes through membranes, skin and blood brain barriers

Question 15

T/F: Elemental mercury is readily absorbed orally and throughout the GI tract

Answer 15

False- little to no oral or GI absorption

Question 16

T/F: Lungs will NOT absorb elemental mercury vapor

Answer 16

False- Lungs ABSORB elemental mercury vapor

Question 17

What happens if you inhale elemental mercury vapor (liquid metal):

Answer 17

Can have toxic CNS effects with breathing lots of vapor

Question 18

When might there be risk for inhalation of elemental mercury vapor?

Answer 18

In occupational setting or mercury spills in poorly ventilated areas

Question 19

What type of mercury is used in dental amalgam?

Answer 19

ELEMENTAL MERCURY

Question 20

What types of mercury are found in compounds used extensively in industry?

Answer 20

Inorganic mercury salts

Question 21

List some inorganic mercury salts: (4)

Answer 21

1. mercuric chloride
2. bromide
3. sulfate
4. nitrate

Question 22

What is the LEAST toxic form of mercury?

Answer 22

Inorganic mercury salts

Question 23

Describe the GI absorption of inorganic mercury salts:

Answer 23

Poor absorption

Question 24

Describe the GI absorption of the following forms of mercury:

1. methyl mercury - natural
2. elemental mercury - liquid metal
3. inorganic mercury salts

Answer 24

1. 95% GI absorption
2. no GI
3. poor GI absorption

Question 25

What happens with high levels of inorganic mercury salts:

Answer 25

Mercuric ions concentrate in kidneys, acute toxicity and renal necrosis

• note: this is still the least toxic form of mercury

Question 26

T/F: inorganic mercury salts are water soluble and can lead to environmental pollution

Answer 26

True

Question 27

Amalgam restorations have been used for:

Answer 27

150 years

Question 28

List some benefits of amalgam restorations:

Answer 28

1. affordable
2. durable
3. safe
4. longevity

Question 29

Up to 75% of amalgam restorations last for 15+ years

Answer 29

False- 80%

Question 30

T/F: With amalgam restorations, the Hg will not enter the pulp, bone or gingiva

Answer 30

True

Question 31

When is the risk for Hg vapor release with amalgam restorations?

Answer 31

1. mixing/insertion
2. polishing & removal (due to heat)

Question 32

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

Answer 32

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

Question 33

List the percentages of overall environmental mercury release:

____ fuel combustion

___ waste combustion

___ manufacturers & consumers

____ from dentistry

Answer 33

53% fuel combustion
34% waste combustion
13% manufacturers & consumers
LESS THAN 1% from dentistry

Question 34

To control dental Hg release:

Answer 34

Amalgam waste must be handled correctly

Question 35

List what comprises the amalgam waste capture device:

Answer 35

1. chairside trap
2. vaccum pump filter
3. amalgam separator

Question 36

What is contact amalgam?

Answer 36

Amalgam that has contacted the patient

Question 37

What are some forms of contact amalgam?

Answer 37

1. Carving scrap
2. extracted teeth
3. amalgam in traps, filters or screens

Question 38

Non-contact amalgam:

Answer 38

Left over mix