DH102 MIDTERM

After a plain local injection, the local blood vessels in the area of injection will immediately begin to absorb the local anesthetic causing:

Vasodilation of the blood vessels & increased blood flow to the site of injection

Local anesthetic agents with vasoconstrictors are generally more acidic than plain formations. The reason local anesthetics with vasoconstrictors are more acidic is because of the presence of sodium bisulfite

Both statements are true

Inflamed tissue experiences an increase in vascularity, slowing the onset of anesthetic action; however, in healthy tissues the onset of action and the duration of action is more predictable

True

What do local anesthetic drugs inhibit in order to prevent nerve cell stimulation?

Sodium influx

Special consideration should be given to the use of 1:100,000 epi in

-Patients who have uncontrolled hyperthyroid clinical symptoms

-Hyper-responders

-ASA 3 or 4 cardiovascularly compromised persons

Local anesthetics cross both the placenta and blood brain barriers

True

Patient comfort can be increased by the sharpness of the bevel. The bevel of the needle should be turned toward the bone.

Both statements are true.

Which nerve is anesthetized through localized diffusion of the local anesthetic agent through the tissue when administering an inferior alveolar block?

Lingual nerve

A major cause of needle injury is:

-Not using the 'scoop' method

-Sudden, unexpected patient jerking

-Inattentiveness of administrator

The onset of action for benzocaine is rapid. The duration of action for benzocaine is 5 to 15 minutes.

Both statements are true

2% Lidocaine w/epi 1:100,000 provides 60 minutes pulpal anesthesia.

True

Gauge refers to the diameter of the lumen.

True

Although topical anesthetics are generally regarded as safe, if used improperly they can produce adverse reactions that are fatal

True

Which of the following anesthetics are combined with levonordefrin?

2% mepivacaine

Ester local anesthetics are metabolized in which one of the following pathways?

In the blood plasma

Persons who remain anesthetized longer than expected are called:

Hyper-responders

Studies show effective hemostasis with 1:100,000 epi

True

Needle breakage most often occurs at the hub.

True

What is another name for the elimination of the local anesthetic from the blood and tissues?

Half-life

What should the clinician do while waiting for the local anesthetic to take effect on the patient (besides assembling the syringe)?

Observe the patient for possible signs of an adverse reaction

Decreasing the bleeding at the site of injection is an example of

Hemostasis

The primary effects of local anesthetics occur during what phase?

Depolarized

Why is severe liver disease (ASA IV) a contraindication for local anesthetic administration?

The patient will have prolonged bleeding

Name the most commonly used vasoconstrictor, the most potent, and 'benchmark' of all vasoconstrictors.

Epinephrine

Drawing the blood into the anesthetic cartridge is called

Positive aspiration

The BEST way to store local anesthesia cartridges is at

Room temperature

Which anesthetic agent is more concentrated?

Topicals

The colored band on the anesthetic cartridge indicates:

Which anesthetic is on the inside of the cartridge

The part of its chemical structure that determines if a local anesthetic agent will be an ester or amide is the:

Intermediate hydrocarbon chain

Mantle bundles are fasciculi located near the outside rim of the nerve

True

What is the maximum recommended dose of epinephrine per appointment for a health patient?

0.2 mg

The nerve cell stage in which nerve membrane is at rest -70mv.

Polarization

The regular gaps that are present between two adjoining Schwann cell cytoplasm and its nucleus are called:

Nodes of Ranvier

Since the syringe was introduced in 1921, what has been the single most important improvement in the dental local anesthetic syringe?

The addition of the aspirating harpoon

Which of the following are best practices to follow when administering local anesthesia of any kind in the dental office?

-Review the patient's health and dental history at all appointments.

-Use the lowest concentration of anesthesia to satisfy clinical requirements

-Limit the area of application

-Know the concentration of the drug being used

Which part of the maxilla articulates with the zygomatic bone laterally, thus completing the infraorbital rim?

Zygomatic process

What is produced when the thumb ring of a syringe is pulled back by the clinician, causing retraction of the rubber stopper?

Negative pressure

Effect(s) of Methemoglobinemia is the clinical observation of:

A bluish skin tone, nail beds and lip

How many milligrams of epinephrine can a healthy adult receive at one dental appointment?

0.2

What are other name(s) for axons?

-Core bundles

-Mantle bundles

-Nerve fibers

Which of the following characteristics could contribute to the properties of an ideal intraoral topical anesthetic?

Allow pain-free application

The lower pH of inflamed tissues (5-6) will more likely produce a very comfortable and faster onset when anesthetized with a local anesthetic

False

What factor/factors determine the severity of an overdose reaction to local anesthetic?

-Degree of drop in blood pressure

-Time lapse between the administering of the local anesthetic to the overdose

-Number of symptoms patient experiences

Pulpal anesthesia can be achieved using a 2.5% Lidocaine and 2.5% Prilocaine gel mixture

False

What is the layer of connective tissue that surrounds each axon within a nerve called?

Endoneurium

Which nerve supplies innervation to the second and third maxillary molars?

PSA

"Relative contraindication" means that a local anesthetic may be administered, but only after careful weighing of the risk versus the benefit to be gained

True

30 gauge needles have a similar internal diameter than 25 gauge needles

True

What is a 1:1000 dilution of epinephrine used for?

Epi pen for anaphylaxis

Benzocaine is available in all of the following preparations EXCEPT one. Which one is the EXCEPTION?

Injectable

The body's response to fear provokes symptoms that could include

-Irritability

-Muscular tension

-Increased blood pressure

The two local anesthetics with the least vasodilatory properties are:

Prilocaine & Mepivacaine

In dentistry, the pressure-type syringe is used for providing anesthetic for periodontal ligament injections. It provides reliable anesthesia for one tooth in the mandible.

Both statements are true

How long should it take to deposit one cartridge of anesthetic?

At a rate of 1.8 mL per 2 minutes

What factor/factors influence(s) the duration of the effects of local anesthetics?

-Degree of protein binding

-Vascularity of injection site

-Addition or absence of a vasoconstrictor

The needle should be changed after every injection

False

Dull needles can cause pain upon insertion and withdrawal

False

Prilocaine is biotransformed in the liver only

False

What is the solution that used to be added to the cartridge of local anesthetic to prevent bacterial growth?

Methylparaben

Which is the primary factor that determines the onset of action?

pKa of the anesthetic agent

Epinephrine and Norepinephrine are stress hormones and neurotransmitters

True

Topical anesthetics are available in both esters and amides

True

Needle fishhook barbs are produced by:

Contacting bone forcefully

In a resting neuron, what positive ion is most abundant outside the plasma membrane?

Sodium

Vasopressor is another name for a:

Vasoconstrictor

The main difference between motor neurons and sensory neurons is the location of which body part?

Cell body

Which is the number of times a clinician should aspirate before administering a local anesthetic solution

Twice

The bevel of the needle should:

Be turned toward the bone

Core bundles are fasciculi located near the center of the nerve and are responsible for anterior teeth

True

Beta 1 receptors primarily affect the lung. Beta 2 receptors primarily affect the heart.

Both statements are false

Which component of the local anesthetic molecule improves the lipid solubility, facilitating the penetration of the anesthetic through the lipid-rich membrane where the receptor sites are located?

Lipophilic aromatic ring

What is the name of the most potent ester topical anesthetic?

Tetracaine hydrochloride

All of the following are true regarding the nodes of Ranvier EXCEPT one? Which one is the EXCEPTION?

Occur at unevenly spaced intervals

The length of the short needle is 30mm. The length of the long needle is 40mm

Both statements are false

Which of the following may cause an endogenous release of epinephrine?

-An injection of epinephrine

-Anxiety related to a divorce

-Apprehension about a dental appointment

What is the most common topical preparation for lidocaine?

Ointment/Gel

What is the solution that is added to the cartridge of local anesthetic that can trigger bronchospasm?

Sodium bisulfite

Adverse reactions associated with topical anesthetic is:

-Tissue discoloration

-Sloughing

-Burning and stinging

A small Nitrogen gas bubble of 1-2 mm is normal and found under the cap of cartridges

True

The two types of adrenergic receptors are called:

B&C

All topical anesthetics should be placed for 1-2 minutes; they absorb into all tissues at a different rates.

T, T

Why is the pterygoid plexus an area of concern when administering the PSA?

It is a highly vascular area

Which of the following concentrations of epinephine is the most diluted?

1:200,000

Which of the following describes an action potential in a neuron?

Travels down an axon toward the synapse

What are the nerves that conduct signals away from the brain or spinal cord called?

Efferent nerves

Which of the following intraoral needle gauges used in dentistry are listed from the smallest to the largest

30, 27, 25

Larger-gauge needles provide less tissue deflection during significant needle penetration because of the greater rigidity of larger gauge needles

True

The lower the pKa number, the faster the onset of action of a local anesthetic

True

Which of the following is NOT an effect of epinephrine?

It constricts the bronchioles

Which of the following four types of nerve fibers has the fastest conduction velocity?

Myelinated large fibers

The color-coded band on the anesthetic cartridges identifies what?

Anesthetic drug inside the cartridge

The most potent local anesthetic is bupivacaine, which has the greatest degree of lipid solubility

True

Which concentration ratios of epinephrine are the most dilute between 1:50,000, 1:100,000 and 1:200,000

1:200,000

Which local anesthetic would be the best choice for a patient with known sensitivity to epinephrine and a need for approximately 30 minutes of pulpal anesthesia?

3% Mepivacaine plain

Patients with uncontrolled hyperthyroid disease should have limited amounts of:

Lidocaine w/epinephrine

Which structures of the body are most likely to experience the loss of sensation after the administration of an anesthetic agent to the lingual nerve?

-Floor of the mouth

-Body of the tongue

-Lingual gingival tissue of the mandibular teeth

A patient exhibits signs of an allergic reaction after receiving one cartridge of 2% lidocaine with 1:100,000 epinephrine. Which content of the cartridge is most likely responsible?

Sodium bisulfite

Four percent Articaine with 1:200,000 epinephrine provides how much time of pulpal anesthesia?

60-75 mins

All of the following are considered advantages for the use of topical anesthetic agents EXCEPT one. Which one is the EXCEPTION?

Can be purchased over the counter

At the synaptic knobs of neuron cells, what type of action is required to have the electrical impulse cross the synapse of one cell to another cell?

The action of either electrical or chemical synapses2