Local anesthesia Four Flashcards
____ -_____ : cartridge is inserted into the syringe from the side
Breech-loading:
______ :
with harpoon, it engages thick silicone rubber stopper
at the tail end of the cartridge
Negative pressure will cause blood (if there) to be
visible in the cartridge
Aspirating
____ ____: Thumb ring forces solution through needle to patient
Positive Pressure
It is important for the clinican to be aware of the ____ _____ coming off of the syringe.
Needle adaptor
WIth the ____ _____ it is Possible to achieve consistently reliable
pulpal anesthesia of one isolated tooth in
the mandibular arch
pressure syringe
t/f: 1947 Figge and Scherer introduced “needle-less” injection
true
What is the basis of the Jet injector?
Liquids forced through very small openings called jets, at very high pressure can penetrate intact skin or mucous membrane
t/f: One still need nerve block and infiltration with a jet injector.
true
Jet injector is NOT an adequate substitute for needle
and syringe.
What are the advantages of a disposable syringe?
- single use
- sterile until opened
- lightweight
What are the disadvantages of a disposable syringe?
does not accept prefilled dental cartridges
difficult aspiration (usually need to hands
With a ______-______ ____ _____ ______ _____, there is Constant flow rate of
local anesthesia, and Controlled rate of fluid
administration =
reduced pain
perception
Computer-Controlled Local Anesthesia Delivery System
t/f: One should do the following while taking care of your instruments:
1 Wash the syringe after each use
2 Dismantle and lubricate every 5 autoclavings
3 Clean Harpoon with brush after use
4 Replace piston and harpoon on regular basis
true
T/f: with the bevel of the stainless steel needle, the Greater angle the bevel, greater the degree of deflection.
true
_______ =Diameter of the lumen of the needle
gauge
t/f: Smaller the gauge #, Greater the diameter.
true
t’f: Patients feel the same regardless of gauges of needle.
true
it has been demonstrated that patient is unable
to differentiate among 23-, 25-, 27-, and 30-gauge
needle.
(His wording is so confusing)
What are some advantages of larger gauge needle (smaller gauge number)
Less deflection, as needle advances through tissues Greater accuracy in injection Less chance of needle breakage Easier aspiration No perceptual difference in patient comfort
_____ -gauge needles should be used when there is a
greater risk of positive aspiration
Larger-gauge
Red:
25- gauge
Yellow:
27- gauge
Blue:
30- gauge
_______ becomes important when needle
must penetrate a greater thickness of tissue
Deflection
With a ____ ___ _____ the Needle tip is at the lower edge of the needle shaft
Conventional Dental Needle
With a __________ ______ the tip of needle is at the center of the shaft
Nondeflecting Needle
__________ ____ _____:
Rotate handpiece or needle in a back-and- fore rotational movement while advancing the needle
Birotational Insertion Technique
t/f:
Average short needle is 20mm
Average long needle is 32mm
true
What is the weakest portion of the needle?
the hub
t/f: Needles should not be inserted into tissues to their hub unless it is
absolutely necessary for the success of the injection
true
______ _ _____:
Never used on more than one patient
Change after 3 or more tissue penetration
Must cover in protective sheath when not
use
Pay attention to the position of uncovered
needle tip
Proper disposal is necessary
Recapping using “Scoop” technique
handling of needle
What can cause pain upon insertion?
dull needle
the following are the most common “____ ____” procedures:
Inferior alveolar nerve block
Posterior superior alveolar nerve block
Intrapulpal injection
PDL injection and Intraosseous injection
Bent needle
t/f: “ there is no injection technique used in dentistry that
mandates that the needle be bent for the injection to be
successful”
true
t/f: Don’t change direction of a needle when
its embedded in tissue, instead pull out and reinsert.
true
t/f: Dr. Kao suggests always using a 27 gauge and long needles to prevent needle breakage
true
U.S. dental cartridge contains_____ ml of local
anesthetic solution
1.8ml
the ______ of the cartridge is made of silicon and Receives the harpoon of the aspirating
syringe
plunger
the ____ of the cartridge is a Semipermeable membrane (latex rubber), and where needle penetrates into the cartridge.
diaphragm
Calculate the mg of drugs in a 1.8 ml cartridge of 2% lidocaine.
2% = 20mg/ml and we have 1.8ml so
20 mg/ml X 1.8 ml = 36 mg
some cartridges may contgain a ________. Examples include:
Sodium bisulfite (antioxident)
Sodium bisulfite oxidize to Sodium bisulfate
Vasopressor
___ in the cartridge makes the solution isotonic with tissue
NaCl
Contents of the cartridge:
medication
May have Vasopressor
NaCl
Distilled water
t/f: Store cartridges in room temperature in a dark place
true
t/f: Do NOT soak cartridge in alcohol or “cold sterilizing
solution”
true
the bubble in the cartridge is normally Nitrogen gas, but if there is a bubble larger than 2mm this could be a result of a _____ cartridge and is not normal.
frozen
What can causes burning on patient injection?
pH, alcohol, heat, expiration date..
Dental cartridges must never be used on more
than one patient
Cartridges should be stored at room
temperature
It is not necessary to warm cartridges before use
Cartridges should not be used beyond their
expiration date
Cartridges should be checked carefully for
cracks, chips and integrity of the stopper and
cap before use
Recommendations for proper cartridge handling (good to know)
t/f: Benzocaine > Lidocaine topical (reduced overdose potential)
true
Most undesirable reaction to local anesthesia are______ to the act of drug administration
responses
What are the most common psychogenic reactions
Vasodepressor syncope
Hyperventilation
One should update medical history questionnaire every ___ months
6 months
For patients with ______ the following is recommended:
Avoid techniques with ↑ chance of + aspiration
• Use supraperiosteal, PDL, Intraosseous
coagulopathies
t/f: CHF with disability (ASA III or ASA IV) may demonstrate ↓ liver perfusion ↑ t ½ amide
local anesthesia
true
ASA ____ cardiovascular risk pt is not a candidate
for vasopressors or elective dental care
Recent (< 6 months) or repeated MI increases risk
during dental care or local injection
ASA IX
During what two stages of pregnancy is it contraindicated for LA?
1st and 3rd trimester
t/f: Cimetidine + ASAIII CHF = relative contraindication for amide local anesthesia
true
____ ____ can Enhance cardiovascular action to
exogenously administered vasopressors. This results in 5 -10 X increase with levonordefrin and Nore-epi, and 2 X increase with epinephrine. THIS CAN LEAD TO HYPERTENSIVE CRISIS= DEATH
Tricyclic Antidepressant (TCAs)
__ hrs is needed for Cocaine clearance
72
t/f: Epinephrine-impregnated gingival retraction cord is absolutely contraindicated in the cocaine abuser
true
