500+ QUESTIONS AND ANSWERS |
COMPREHENSIVE & RATED A+ | 2026/2027
GUIDE
When a syringe is reloaded with a second local anesthetic cartridge and
a needle is already in place, care must be taken to ensure that the
needle penetrates the center of the rubber latex diaphragm. An off
center perforation can result in what? - Correct Answer - lack of flow of
anesthetic solution through the needle
Which of the following theories of the mode of action of local anesthetics
states that local anesthetics act by binding to specific receptors on the
sodium channel eliminating the permeability of the nerve membrane to
sodium ions and preventing the conduction of a nerve impulse? - Correct
Answer - Specific Receptor Theory
According to research, 50-80% of dental fear and anxiety is based on
experiences that occurred during a patient's childhood or adolescence -
Correct Answer - True
,Saltatory conduction is a term that refers to
_______________________. - Correct Answer - Impulse conduction in
myelinated nerves
What is the reason for aspirating prior to delivering an injection? -
Correct Answer - To avoid an intravascular injection
Local anesthetics anesthetize an area of deposition by
_____________________. - Correct Answer - making the nerve
membrane LESS permeable to Na+
The period during which a nerve cannot conduct an impulse just after
completing an impulse called the______________________. - Correct
Answer - Absolute refractory period
During depolarization, the nerve membrane increases in permeability to
________ ions - Correct Answer - Sodium
In myelinated nerves, local anesthetic molecules must diffuse through
the myelin sheath to reach the nerve membrane in order to block the
nerve impulse. - Correct Answer - False
Most topical anesthetics are what classification? - Correct Answer -
Esters
,The pKa of a local anesthetic solution has the greatest influence on the
anesthetic's _____________. - Correct Answer - onset
Nerve conduction and impulse spread is faster on _______________
nerve fibers - Correct Answer - myelinated
Which type of local anesthetic molecule passes through the nerve
membrane into the axoplasm? - Correct Answer - Uncharged free base
(RN)
Inflammation exhibits which of the following effects on local anesthesia?
- Correct Answer - Decrease effectiveness due to a decrease in pH of
inflamed tissue and increased vascularity
The level of protein binding to local anesthetic molecules affects which of
the following? - Correct Answer - Duration of action
Fasciculi that are located near the surface of the nerve and innervate the
more proximal regions of the nerve (molar teeth) are termed
______________ bundles. - Correct Answer - mantle
_______ is an increased tolerance to a drug that is administered
repeatedly. - Correct Answer - Tachyphylaxis
, Nerve conduction and impulse spread is faster on _______________
nerve fibers. - Correct Answer - myelinated
Which of the following is an antioxidant that functions as preservative in
local anesthetic solutions? - Correct Answer - Sodium bisulfite
During depolarization, the nerve membrane increases in permeability to
________ ions. - Correct Answer - sodium
The pKa of a local anesthetic solution has the greatest influence on a
local anesthetic's ____________. - Correct Answer - onset
A bubble found in anesthetic cartridges that do not have an extruded
rubber stopper is ________________. - Correct Answer - nitrogen gas
A local anesthetics without a hydrophilic part in their molecular structure
are only useful as a __________ - Correct Answer - topical
The function of sodium chloride in the local anesthetic solution is to
______________________. - Correct Answer - produce isotonicity with
the body tissue