Armamentarium Flashcards
Aspirating:
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
label
Caring for Your Instruments
washing?
lubrication?
harpoon?
piston and harpoon replacement?
Wash the syringe after each use
Dismantle and lubricate every 5 autoclavings
Clean Harpoon with brush after use
Replace piston and harpoon on regular basi
needle anatomy
factors of the shaft?
greater bevel=?
Bevel, shaft, the hub, and cartridge penetrating end
Shaft has two important factors
• Diameter (gauge)
• Length (from tip to the hub)
Greater angle the bevel, greater the degree of deflection
needle gauge
Diameter of the lumen of the needle
Smaller the gauge #, Greater the diameter
• Example 25-gauge has greater internal than 30-gauge internal diameter
are smaller needles less painful?
This assumption is unwarrnated !!!
Hamburg (1972) demonstrated that patient is unable to differentiate among 23-, 25-, 27-, and 30-gauge needle.
Bottom line
Patients feel the same regardless of gauges of needle
Advantage of Larger Gauge Needle
defelction?
accuracy?
breaks?
aspiration?
pt comfort?
Less deflection, as needle advances through tissues
Greater accuracy in injection
Less chance of needle breakage
Easier aspiration
No perceptual difference in patient comfort
when should larger gauge needles be used
Larger-gauge needles should be used when there is a
greater risk of positive aspiration
colors of gauges
Red: 25- gauge
Yellow: 27- gauge
Blue: 30- gauge
Deflection of needle
Deflection
Deflection of needle will differ according to gauges
Deflection becomes important when needle must penetrate a greater thickness of tissue
Conventional Dental Needle
Needle tip is at the lower edge of the needle shaft, deflection
Nondeflecting Needle
The tip of needle is at the center of the shaft
But over years of use, dentists become accustomed to deflecting needle
needle length
weakest portion?
should entire needle ever be completely injected?
Long and short
Average short needle is 20mm
Average long needle is 32mm
Weakest portion of the needle is at the hub
Needles should not be inserted into tissues to their hub unless it is absolutely necessary for the success of the injection
Handling of Needle
Never used on?
Change after?
Must cover?
Pay attention to?
Proper disposal?
Recapping?
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
Pain on insertion due to
dull needle
Breakage of needle
Do not bent needle if to be inserted into >5mm soft tissue depth
• Most commonly “bent needle” procedures are
Inferior alveolar nerve block
Posterior superior alveolar nerve block
Intrapulpal injection
PDL injection and Intraosseous injection
changing needle direction in tissue?
Don’t change direction of a needle when its embedded in tissue
Pain on withdraw may caused by?
Pain on withdraw may caused by “fishhook” barb on the tip
cartridge overview
holds what V?
reffered to as?
some made of?
The glass cylinder can hold 2ml of solution
U.S. dental cartridge contains 1.8ml of local anesthetic solution
Dental cartridge is commonly referred as “carpule”
Some cartridge are made of plastic cylinder instead of glass
Plastic cylinder isn’t able withstand extended force and will leak
label
Cartridge Contents
Calculation of mg of drug in the cartridge
Local anesthetic drug is the main player !!
Calculation of mg of drug in the cartridge
• Example: 2% lidocaine in a cartridge (1.8ml)
2% = 20mg/ml and we have 1.8ml so
20 mg/ml X 1.8 ml = 36 mg
this means we have 36mg of lidocaine in a cartridge
• How about 3% Mepivacaine in a cartridge
3% = 30mg/ml and we have 1.8ml so
possible add in for cartridges
May have Vasopressor
Sodium bisulfite (antioxident)
Sodium bisulfite oxidize to Sodium bisulfate
NaCl
make solution isotonic with tissue
Distilled water
how can cartridge be cleaned?
no soaking, use of a moistened wipe with 91% ispropyl or 70% ethyl
Care and Handling of cartridges
No manufacturer claim of sterility about exterior surface of the cartridge
Bacterial culture tested fail to produce any growth
Cannot withstand extreme temperature
No autoclaving especially plastic cartridge
When heated, vasopressors are destroyed
Store in room temperature in a dark place
Study showed no benefit of using cartridge warmer
Do NOT soak cartridge in alcohol or “cold sterilizing solution”
Semipermeable diaphragm permits diffusion of these solution
Read the drug package insert
Problems with cartridges
bubble?
extruded stopper?
how to fix?
Bubble in the cartridge- Small bubble 1-2 mm are usually nitrogen gasand Large bubble with extruded stopper
Extruded Stopper- >2mm bubble due to frozen cartridge or If no bubble, may caused by diffusion of other agent through diaphragm
• Wescott demonstrated measurable alcohol in cartridge after only one day of immersion in alcohol solution
Corroded Cap
If immersed in disinfecting solution
Only sterilization needed are
• 91% isopropyl alcohol
• 70 % ethyl alcohol
Burning on injection due to
pH, alcohol, heat, expiration date..
cartridge use on more than one?
stored at what temp?
warm before use?
expiration date?
check for?
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
Topical antiseptics before injection optional)
Betadine
Chlorhexidine
Topical anesthetic prior to injection
Placed directed with applicator for 1 min
• Stern and Giddon demostrated topical to mucous membrane for 2-3 mins leads to profound soft-tissue analgesia
Benzocaine > Lidocaine topical (reduced overdose potential)
Off label use of EMLA but its biter
Unmetered spray is not recommended
Preparing of the Armamentarium steps
retract piston
insert cartidge
Engage the harpoon in plunger with GENTLE finger pressure
Plastic hubbed needle is screwed onto the syringe
Scoop the needle cap
unload and retract the piston
Costly Mistake with post injection
When discarding needle, make sure metal needle adaptor is not discarded
Most common psychogenic reactions
Vasodepressor syncope
Hyperventilation
Medical History Questionnaire
Update every?
allergies?
bleeding?
avoid techniques that?
HF?
Update every 6 months
Allergy
-True, documented, and reproducible allergy to amide is virtually nil
-Epinephrine allergy most likely due to exaggerated physiological response
Bleeding problems (Coagulopathies)
Avoid techniques with ↑ chance of + aspiration
-Use supraperiosteal, PDL, Intraosseous
Heart Failure
-CHF with disability (ASA III or ASA IV) may demonstrate ↓ liver perfusion ↑ t ½ amide
local anesthesia
ASA IV cardiovascular risk pt is not a candidate for?
ASA IV 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
Judicious use of vasopressors in L.A. is __________ in stable angina
Judicious use of vasopressors in L.A. is not contraindicated in stable angina
(Unstable angina = ASA IV)
AIDS, Hepatitis A,B, Jaundice… increase half time of?
AIDS, Hepatitis A,B, Jaundice… ↑ t ½ amide
Seizure
Causes?
Stress Reduction?
Causes
• Stress / Anxiety
• Hypoglycemia
• Hyperventilation
Stress Reduction protocol is needed
Pregnancy and injections
Relative contraindicated especially at 1st trimester
Consultation with OB-GYN is needed
TCAs and LA
type on contraindication?
Tricyclic Antidepressant (TCAs)
- Enhance cardiovascular action to exogenously administered vasopressors
• 5 -10 X increase with levonordefrin and Nore-epi
• 2 X increase with epinephrine
–What’s the big deal ?!=Hypertensive crisis =death
Drug-Drug Interactions
Cimetidine?
H2 receptor blocker?
Cimetidine + ASAIII CHF = ?
what sort of contrainidcation?
Cimetidine ↑ t ½ of circulating local anesthesia
H2 receptor blocker compete with lidocaine for hepatic oxidative enzyme
Cimetidine + ASAIII CHF = relative contraindication for amide local anesthesia
other relative contraindications of LA?
Malignant Hyperthermia and Methemoglobinemia (to Prilocaine)
cocaine drug to drug interaction
contraindication type?
Cocaine stimulate nore-epi release and inhibit reuptake
Tachycardia / hypertension = ↑ myocardio O2 requirement = Cardiac ischemia = MI
72 hrs is needed for Cocaine clearance
Dental correlation:
Epinephrine-impregnated gingival retraction cord is absolutely contraindicated in the cocaine abuser
Postpone dental treatment, if suspected cocaine usage within 24 hours
reuse needles?
no
covered with sheath when not in use?
yes
how to recap needle
one handed scoop
should needles be bent in cases where if it difficult to access for a block
no
what bacteriostatic agent was removed from cartridges?
methylparaben
bevel angle importance
greater angle means more deflection
bevel bone relation
towards bone, prevent periosteum from being punctured
