CRDTS EXAMPREP 2026 FULLY SOLVED
EDITION WITH DETAILED SOLUTIONS
◉How does a nerve conduct an impulse? Answer: By sequential neuron
cell membrane depolarization from segment to segment or node to node
◉The two stages of an action potential are: Answer:
Depolarization/repolarization
◉Local anesthetic agents prevent depolarization by: Answer:
Preventing transfer of Na. ions from the exterior of the nerve to the
interior
◉Once the minimal threshold stimulus has been reached, the impulse
will travel the entire length of the fiber without stimulation. This
explains: Answer: All-or-none law
◉The gauge of a dental needle MOST recommended for intraoral
injections with high risk of aspiration is: Answer: 25 gauge
◉All of the statements concerning local anesthetic needles are true
EXCEPT one. Which one is the EXCEPTION?
The term gaugerefers to the diameter of the lumen of the needle
,The weakest portion of the needle is at its hub
Larger needles provide more reliable aspirations
Disposable needles will not normally become dull for at least 10
insertions
Larger needles should be employed when a greater risk of positive
aspiration exists Answer: Disposable needles will not normally become
dull for at least 10 insertions
They dull after 3-4 insertions
◉All of the statements concerning local anesthetic cartridges are true
EXCEPT one. Which one is the EXCEPTION?
The glass dental cartridge should not be autoclaved
No alcohol should be present around the cartridges when they are stored
outside the packaging container
The rubber plunger is treated with silicone to decrease the incidence of
"sticky stoppers"
Cartridges exposed to extended periods of direct sunlight may have their
contents undergo accelerated destruction
Manufacturers recommend freezing cartridges so that they may be used
beyond the posted expiration date Answer: Manufacturers recommend
freezing cartridges so that they may be used beyond the posted
expiration date
Freezing will cause pain upon depositing
, ◉The purpose of aspirating before injecting a local anesthetic solution is
to prevent: Answer: Intravascular injections
◉Why do local anesthetics NOT work well in infected tissues? Answer:
The lower pH of infected tissue
Increased edema
Increased vascularity
◉Lidocaine is metabolized primarily in the: Answer: Liver
◉Complete the sentence with the MOST accurate phrase. Local
anesthetics______________________. Answer: Dissociate in the
tissues, liberating free base, which can diffuse through the nerve
membrane
◉Tissues with higher pH will cause:
Rapid hydrolysis of the anesthetic solution:
Decreased disassociation of the anesthetic drug)
Increased disassociation of the anesthetic drug Answer: none of the
above
◉The amount of anesthetic in a cartridge of 4% prilocaine is Answer:
72mg
EDITION WITH DETAILED SOLUTIONS
◉How does a nerve conduct an impulse? Answer: By sequential neuron
cell membrane depolarization from segment to segment or node to node
◉The two stages of an action potential are: Answer:
Depolarization/repolarization
◉Local anesthetic agents prevent depolarization by: Answer:
Preventing transfer of Na. ions from the exterior of the nerve to the
interior
◉Once the minimal threshold stimulus has been reached, the impulse
will travel the entire length of the fiber without stimulation. This
explains: Answer: All-or-none law
◉The gauge of a dental needle MOST recommended for intraoral
injections with high risk of aspiration is: Answer: 25 gauge
◉All of the statements concerning local anesthetic needles are true
EXCEPT one. Which one is the EXCEPTION?
The term gaugerefers to the diameter of the lumen of the needle
,The weakest portion of the needle is at its hub
Larger needles provide more reliable aspirations
Disposable needles will not normally become dull for at least 10
insertions
Larger needles should be employed when a greater risk of positive
aspiration exists Answer: Disposable needles will not normally become
dull for at least 10 insertions
They dull after 3-4 insertions
◉All of the statements concerning local anesthetic cartridges are true
EXCEPT one. Which one is the EXCEPTION?
The glass dental cartridge should not be autoclaved
No alcohol should be present around the cartridges when they are stored
outside the packaging container
The rubber plunger is treated with silicone to decrease the incidence of
"sticky stoppers"
Cartridges exposed to extended periods of direct sunlight may have their
contents undergo accelerated destruction
Manufacturers recommend freezing cartridges so that they may be used
beyond the posted expiration date Answer: Manufacturers recommend
freezing cartridges so that they may be used beyond the posted
expiration date
Freezing will cause pain upon depositing
, ◉The purpose of aspirating before injecting a local anesthetic solution is
to prevent: Answer: Intravascular injections
◉Why do local anesthetics NOT work well in infected tissues? Answer:
The lower pH of infected tissue
Increased edema
Increased vascularity
◉Lidocaine is metabolized primarily in the: Answer: Liver
◉Complete the sentence with the MOST accurate phrase. Local
anesthetics______________________. Answer: Dissociate in the
tissues, liberating free base, which can diffuse through the nerve
membrane
◉Tissues with higher pH will cause:
Rapid hydrolysis of the anesthetic solution:
Decreased disassociation of the anesthetic drug)
Increased disassociation of the anesthetic drug Answer: none of the
above
◉The amount of anesthetic in a cartridge of 4% prilocaine is Answer:
72mg
