Endodontic Anesthesia Flashcards
how do you give an atraumatic anesthetic injection
- dry mucosa- then topical anesthetic- let it soak in at least 60 sec
- vigorously shake or gently squeezing the lip or cheek while injecting is a distraction technique thought to activate the faster alpha fibers to close the gate
- slow and gently ( take 60 sec to inject)
- talk to patient constantly
- keep patient occupied
describe the pain of the palatal injection
- almost painless injection
how do you give a palatal injection
use small quantity of LA on palatal tissue which is tight and painful. too much - more than 1/4 carp can slough tissue
- use a refrigerant as a pre injection anesthetic
- should see white patch
what amount should you not exceed in palatal injection
no more than 1/4 carpule
what anesthetic should you use with palatal injection
articaine
which tooth will cause the most issue getting numb with acutely inflamed pulpitis
mandibular molar
why is anesthesia difficult at the mandibular molar
the inherent inaccuracies of mandibular nerve blocks but other problems are also present
“lip signs” do not necessarily indicate:
pulpal aneshesia
why is mandibular infiltration alone useless
due to the density of the cortical plates
why is LA difficult with acute pulpitis
in non inflamed tissue, a normal get channel or pore in the nerve cell will be effectively blocked by a LA resulting in inability to create an AP = no pain
local anesthetic is most effective when the need for it is the _____
least
what can local anesthesia be influenced by
the local availability of free base, as only the non ionized portion can diffuse through the neuronal membrane
when are local anesthetics relatively ineffective
when injected into tissues with an acid pH which is due to reduced release of free base
which types of teeth are very resistant to LA
teeth with acutely inflamed tissues
technique and _____ are equally important to a good result
patient management
what can we do to combat LA problems
- anti inflammatory drug
what do anti inflammatory drugs do to combat LA problems
reduces inflammation, revert the pores to normal and raise the patients pain threshold
what amount of anti inflammatory drug do you give patient
IBU 600 mg one hour prior
what is the efficacy of anti inflammatory drugs to combat LA problems
78%
when can you not tell the patient to take ibuprofen
when you have not already seen the patient, taken history, obtained radiographs, clinical testing or made DX
if you do a good IA block you should have:
lip signs
why must you wait for the infiltrationto work before doing an block
you wont know if the lip signs are from the block or the infiltration
what should you do after you’ve given the block
- wait a few minutes to allow anesthesia in area of IA injection
- then go back and feel the bone and painlessly inject the 2nd carpule where you know you need to be for the IA block
- wait for lip signs and chekc the tooth with percussion and/or cold
where should you inject a mandibular IA
-at the level of the lingula
- just lateral to pterygomandibular raphe at the height of coronoid notch
which direction will the needle travel in relation to the bevel
opposite
what are extra injections we can do after the confirmed block
- intra ligamental injection (PDL)
- intra pulpal injection
- intra osseous injection
most LA agents have an onset of action between ______
1-20 minutes
effective pulpal anesthesia will be routinely gone in_____
30-90 minutes
when should you use LA
for every case at every appointment
what is the most essential element of patient management
the confidence of the patient
what are the two types of local anesthetic agents
- esters
- amides
describe esters
- novacaine, procaine
- more side effects, higher probability of allergic reaction
- no longer in favor or commonly available in the US
describe amides
- duration:
- short, less than 60 min: 3% Mepivacaine
- medium 60-120 min: lidocaine, articaine
- long: greater than 120 minutes: 0.5% BUpivacaine w/ 1:200,000 epi
- vasoconstrictor
- aspirate to avoid intra vascular injection
most pulpal anesthesia will be lost after _____
45 minutes
what allows articaine to penetrate the cortical bone plates
thiophene ring
what do you use for infiltration
articaine
what block should you use for mandibular teeth
gow-gates
how many carpules of lidocaine do we use with mandibular molar
2 carpules
what technique do you use for mandibular anteriors
IA or Gow Gates
what is the extra oral landmark for GG
tragus
what is the intra oral landmark for GG
level of mesio palatal cusp of second molar
what supplemental injection is the first choice
PDL injection
what is the intent with the PDL injection
to force anesthetic solution down along the PDL and through the cribriform plate to reach apical neural elements in the medullary space
describe how to give the PDL injection
- wedge needle as deeply into PDL as possible. start at DB. warn patient of pain at injection
- use @% lidocaine w/ 1:100,000 epi
- duration of anesthesia= 15-30 minutes only
- inject at all 4 line angles
you must have ____ when injecting the PDL
back pressure
the PDL injection may get you into the pulp but maybe not ______
the canals
describe the intra pulpal injection
- last choice
- painful and ultra short acting but immediate relief
- use 30 guage needle wedges as far in canal as possible
- must bind tightly in canal
- warn patient injection must hurt- most painful of injections
- duration: minutes only
- do not repeat this injection
- do distal canal of lower molar first
should you inject into swollen tissue
no
should you inject in cellulitis
usually necrotic pulp so no IP problem but probably very sensitive to palpation and percussion
- may need I&D, drain, antibiotics before pulpal extirpation
how should you inject in local swelling
- infiltrate apically and laterally or do infra orbital block or both
- debride the pulpal spaces and consider incise and drain
what are the general considerations for swelling
- do a regional block away from inflamed area
- increase dose of LA
- change anesthetic
- supplemental anesthetic techniques
- pre med with anti anxiety agents: liquid valium in pineapple juice: 0.25 mg/kg or NO/oxygen sedation
how can you perfect your LA technique
- use an effective, safe and appropriate LA agent
- practice and use the most effective N block technique
- utilize alternative injection locations as applicable
- wait until effective to start TX
how can you demonstrate concern for the patient
- use topical anesthetic
- use endo-ice for palatal injections
- employ gate theory when injecting
- slow injection - reassure patient
- 27 gauge needle
what is the mode of action of LA
- local anesthetics cause reversible interruption of the conduction of impulses in peripheral nerves by causing a local decrease in the rate and degree of depolarization of the nerve membrane such that the threshold potential for transmission is not reached when everything goes well
what are the effects of LA due to
blockage of sodium channels, thereby imparing sodium ion flux across the membrane resulting in disruption of impulse conduction
most local anesthetic agents are _____ that are administered as _______
tertiary amine bases; water soluble hydrochlorides
after injection the teriary amine base is liberated by:
the relatively alkaline pH of normal tissue fluids
in tissue fluid the local anesthetic will be present in both ______
an ionized and non ionized form
the relative proportions of the ionized and non ionized form are based on
the pH in the area
which form diffuses through the nerve sheath, peri neuronal tissues and the neuronal membrane to reach the axoplasm
the non-ionized base
what is the mechanism of action of the non-ionized form
the local anesthetic enters the sodium channel and either occludes the channel or combines with a specific receptor within the channel that results in channel blockade
what is the most commonly used LA agent
2% lidocaine with 1:100,000 epi (xylocaine)
describe 2% lidocaine with 1:100,000
- safe and effective drug. derivative of xylidine (1.7mL/carpule)
- each carpule contains 34mg of anesthetic
- max safe adult dosage = 8 carpules
- detoxified primarily in liver
- no solution proven to be superior for pulpal anesthesia
- not contraindicated in patients with heart disease
- not contraindicated in pregnant women
- not contraindicated in nursing mothers
- because of epinephrine content, should not be routinely used in patients on MAO inhibitors or tricyclic antidepressants
what is the most controversial LA agent
- 4% articaine with 1:200,000 epi (septocaine)
describe 4% articaine with 1: 200,000 epi
- safe and effective drug contains both amide and ester linkage
- each carp contains 68 mg of anesthetic- twice as toxic as lidocaine
- maximum safe adult dosage is 4 carpules
- also contains a unique sulfur molecule
- reputation of providing superior anesthetic effect
- potential to cause neuropathies
-drug interactions with MAO inhibitors, tricyclic antidepressants and phenothiazides
what is septocaine’s potential to cause neuropathies
paresthesia rare but 5 times as likely with lidocaine or mepivicaine
what is the purpose of epinpehine in LA
delays systemic absorption which increases the duration and increases the effectiveness of the LA, also retards bleeding
what anesthetic should you not use in nerve blocks
articaine
what is the potential danger with epinephrine in LA
- with epi in a pt with elevated BP is an untoward further increase in BP - especially with intravascular injection
if the concern is with exogenous epi ranging
0.018mg- 0.054 mg
a 70kg adult will produce endogenous epi at:
0.007mg - 0.014mg/min at rest
a patient at rest produces almost ______ epi/min
1 carp of LA
if a patient is stressed and not numb they will produce endogenous epi at:
0.28mg per min/ 10 carps of La epi/min
major health concern is maintaining profound anesthesia to maintain comfort and:
reduce stress thereby reducing epi
1-2 carps of 1/100k is generally of:
little consequence
what should you do if pt still isnt numb after 3-4 caps
consider re scheduling with sedation
solution to hot maxillary tooth:
- use a regional block
- PSA
- 2nd division block/palatal infiltration
- infraorbital block
solution to hot mandibular tooth
- Gow - Gates injection- includes high rising mylohyoid nerve
walton and abbott found ____ failure of inferior alveolar block
47%
malamed’s study claims ____ success with the gow gates block
97.25%
