Good to Knows from all weeks of pain management up until midterm & practice questions

Who was the first to try Nitrous Oxide for dental pain control?

Dr Horace Wells in 1844

What is the most popularly used anesthetic in dentistry?

Lidocaine

Definition of "Pain".

Sensation of discomfort that ranges from mild to severe

Definition of "Pain Perception" & its variability amongst individuals.

Neurologic experience of pain, the stimuli is received & transmitted to the brain.

Has little variability amongst individuals

Definition of "Pain Reaction" & its variability amongst individuals.

Ones personal interpretation & response to the pain message

Is highly variable amongst individuals

What is the pain reaction threshold?

The point at which a sensation starts to be painful & discomfort results

What is the function of Afferent Nerves?

Carries signals from sensory neurons to the spinal cord/ brain

What is the function of Efferent Nerves?

Carries motor signals from the brain/spinal cord

T/F: Pain perception is a neurologic experience of pain where stimuli are received and transmitted to the brain. Pain reaction and personal interpretation and response to pain is highly personal among individuals

Both True

Definition of a Neuron

Basic functional unit of nervous system & sends impulses (communication) between the CNS & the rest of the body

Axons bundled together are referred to as...

A nerve

What is a nerve made up of?

Bundles of axons

What are axons wrapped in?

They are individually wrapped in a layer of connective tissue called endoneurium

What is a fascicle?

Axons bundled together in a group

What is a fascicle wrapped in?

Wrapped in a layer of connective tissue called perineurium

What wraps around an entire nerve?

Epineurium

What are mantle bundles?

Fasiculi that are located near the outside of the nerve

What are Core Bundles?

Fasiculi that are located near the center of the nerve

Which fibers in a nerve are the first to become affected by LA and remain anesthetized the longest?

Mantle bundles

What is the input zone of a neuron & its function?

The dendritic region is the input zone & it receives input from other neurons or sensory stimuli

What are the largest nerve fibers?

Type A

Are Type A nerve fibers myelinated or unmyelinated?

Myelinated

Type A nerve fibers are responsible for what type of pain?

Sharp pain sensations

What type of nerve fibers are the smallest?

Type C nerve fibers

What type of nerve fibers are the most numerous?

Type C nerve fibers

Are Type C nerve fibers myelinated or unmyelinated?

usually unmylenated

Type C nerve fibers are responsible for what type of pain?

Dull, aching pains

What nerve fiber requires more anesthetic to provide a complete nerve block?

Type A fibers need more anesthetic than Cs to provide complete nerve blocks

In a resting state, also known as resting membrane potential or polarization, the electrical charge inside the cell membrane is what type of charge?

Negative

Definition of Saltatory Conduction -

Propagation of an action potential along myelinated axons from one Node of Ranvier to the next node

Definition of Action Potential Conduction -

Wave of action potential along unmyelinated fibers, which moves much slower compared to mylinated nerve fibers

What component of a local anesthetic molecule determines whether the molecule is an ester or an amide?

Intermediate Hydrocarbon

This form of local anesthetic molecule can diffuse through lipid rich nerve membranes

Tertiary form

What does an absolute contraindication of local anesthetic mean?

Administration of the offending drug increases the possibility of a life-threatening situation & should not be administered to the patient under any circumstance

What does a relative contraindication of local anesthetic mean?

Administration of the offending drug is preferably avoided due to the increased possibility of an adverse reaction

How many mL of agent is contained in a full unused dental anesthetic cartridge cylinder?

1.8mLs

Ester local anesthetics are metabolized where?

In the blood plasma

Amide local anesthetics are metabolized where?

The liver

Local Anesthetics are Vasodilators or Vasoconstrictors?

Vasodilators

What ingredients are in marketed cetacaine?

benzocaine 14%, butamben 2%, and tetracaine hydrochloride 2%

What topicals have an increased potential for allergic reactions?

Benzocaine and Tetracaine

What is the most potent topical agent?

Tetracaine Hydrochloride

What is noted about Tetracaine Hydrochloride?

This drug can only be combined with other drugs & is to not be used alone.

Symptoms of Methemoglobinemia

pale, blue, short breath, headache

What is the maximum recommended dose for Oraqix?

5 cartridges

What topical anesthetic is not an ester or an amide but is instead a ketone?

dyclonine hydrochloride

Local anesthetic affects what channels?

Affects the sodium channels of the cell membrane

Higher blood levels of a drug increases the chance of a patient developing what?

Overdose

When receiving anesthetic, the patient should be in what position?

Supine position

How fast a nerve fiber conducts an impulse, depends on presence or absence of a myelin sheath and what else?

Diameter of the nerve

Which is the larger diameter needle? 25 Gauge or a 30 Gauge?

25 Gauge

This supplemental injection is specifically used when there is a need for additional hemostatic control with the interdental periodontium in maxillary gingiva

Maxillary intraseptal injection

Where are supraperiosteal injections the most effective in the mouth?

Maxillary arch

When does informed consent need to be obtained when giving LA injections?

Prior to beginning the treatment

In dentistry, what is the most common Medical Emergency?

Vasodepressor Syncope

How is anesthetic administered into the tissue?

S L O W L Y at a rate of 1.8mL in 2 minutes

Aspirations should be done on how many planes?

Always aspirate on 2 planes

The dental needle is most likely to break here due to improper insertion?

The hub

What is the most common type of syringe for local anesthetic administration?

Reusable Breech-Loading Metallic Cartridge-Type Aspirating Syringe (ours)

What syringe is used only for Periodontal Ligament Injections (PDL injections)

Pressure Type Syringes

Where is needle breakage most likely to occur?

At the hub of the needle

What patients should not receive LA with a vasoconstrictor?

Patients who have had a coronary bypass / myocardial infarction / Cerebrovascular Accident in the last 6 months & those who have uncontrolled Diabetes / Hyperthyroidism / Hypertension / Angina / Arrhythmias

What is the MRD for a healthy patient receiving epinephrine?

0.2 mg

What is the MRD for a medically compromised patient receiving epinephrine?

0.04 mg

What strengths does Levonordefrin come in?

Is available ONLY with 2% mepivacaine in 1;20,000

The Maxilla is MORE or LESS porus & MORE or LESS dense than the Mandible?

The Maxilla is more porus and less dense than the mandible

In 72% of the population, this nerve is not present in the oral cavity

middle superior alveolar (MSA)

What is the proper length of time to allow topical anesthetic to remain on the tissue at the injection site? What may happen if you leave it on over this time?

1-2 minutes, tissue sloughing may occur from prolonged use of topical anesthetics

What is the target for MSA blocks?

Height of the mucobuccal fold superior to the apex of the maxillary second premolar

What does a MSA block anesthetize?

Maxillary 1st & 2nd premolars & the mesiobuccal root of the maxillary 1st molar along with the periodontium of the anesthetized teeth & the buccal soft tissue of the premolar region

What percentage of the population has a MSA nerve?

28%

What is the rate of positive aspirations in PSA blocks? Why?

Rate of positive aspiration is 3.1% due to the nearness of the PSA blood vessels

Where is the insertion site for PSA blocks?

Height of the mucobuccal fold superior to the apex of the maxillary second molar, posterior to the maxilla arch with correct angulations to the maxillary occlusal plane & long axis of the tooth

What is the depth of insertion for PSA blocks?

3/4 of a short needle

How much anesthetic is used for a PSA block & how much time to deposit?

1/2 to 1 cartridge over 60 to 90 seconds

What are the vasoconstrictors currently used in the United States?

Epinephrine & Levonordefrin

What can be noted about Articaine when thinking about its composition?

Articaine is the newest LA on the US market & only contains 1.7ml / cc because the manufacture couldn't guarantee each cartridge to have 1.8mL but could guarantee 1.7mL

What is the most commonly used Vasoconstrictor Preservative?

Sodium Bisulfite

Short-acting anesthetics last how long & do they have vasoconstrictors in them?

Have ~ 30 minutes of pulpal anesthesia & they do not contain vasoconstrictors

Intermediate-acting anesthetics last how long & do they have vasoconstrictors in them?

Have ~ 60 minutes of pulpal anesthesia & they do contain vasoconstrictors

Long-acting anesthetics last how long & do they have vasoconstrictors in them?

Have ~ 90 minutes of pulpal anesthesia & they do contain vasoconstrictors

What is added to the cartridge of local anesthetic to prevent oxidation of the vasoconstrictor?

Sodium Bisulfite

What was the first amide suitable for nerve blocks in dentistry?

Lidocaine

What is the most commonly used LA in dentistry in the US?

Lidocaine

Which local anesthetic agent has no reported allergic reactions?

Mepivacaine

Which local anesthetic agent is the least toxic anesthetic available?

Prilocaine

Which local anesthetic agent is 1.5x more potent than lidocaine, mepivacaine and prilocaine

Articaine

Which local anesthetic agent is the most potent & toxic of all the amide anesthetics?

Bupivacaine

TRUE or FALSE: There is only one injectable ester still used in dentistry, Procaine

FALSE: Injectable ester anesthetics are no longer used in dentistry

What is an important post infraorbital injection procedure?

maintain pressure and massage the solution into the infraorbital foramen for approximately 2 minutes to enhance anesthetic diffusion

What should the clinician do if she notices that a patient is developing a hematoma?

apply direct pressure immediately

What anesthetic solution that is no longer used in dentistry is still available in multidose vials and is used in medicine as an antiarrhythmic agent

Novocaine / Procaine (brand vs generic)

T/F: A relative contraindication means that the drug increases the possibility of a life threatening situation which should not be administered to the individual under any circumstances. Absolute contraindication means the offending drug is preferably not used.

Both False