Armamentarium

Question 1

What are the 5 different types of syringes used for LAs in dentistry?

Answer 1

1. Breech-loading, aspirating
2. Breech-loading, self-aspirating
3. pressure-type
4. needleless-type
5. C-CLAD-type

Question 2

What are the five parts of a syringe?

Answer 2

Needle adapter, piston w/ harpoon, syringe barrel, finger grip, thumb ring

Question 3

Normal aspirating, breech-loading, metallic, cartridge-type syringes allow for what three things?

Answer 3

side loading of cartridge, user-controlled aspiration, visualization of cartridge

Question 4

What characteristics do self-aspirating syringes have?

Answer 4

An elastic rubber diaphragm obtains negative pressure for aspiration upon insertion

Question 5

What kind of injection are pressure syringes great for?

Answer 5

they’re ideal for PDL/intraligamentary injections

Question 6

How do needleless syringes inject LA?

Answer 6

with extremely high pressure forcing the solution into the tissue

Question 7

What are the five parts of a needle?

Answer 7

Bevel, shaft, hub, syringe adaptor, and cartridge-penetration end

Question 8

The gauge of a needle refers to what?

Answer 8

The diameter of the lumen inside the needle shaft - the larger gauge, the smaller the diameter

Question 9

Which length of needle tends to break more often?

Answer 9

short needles tend to break more often because they don’t have as much “give” or bend

Question 10

What does the phrase “larger gauge” mean in the clinic?

Answer 10

Unintuitively, it means the lumen diameter is larger despite the actual gauge measurement would be a smaller number

Question 11

What is needle deflection?

Answer 11

It is the ‘bend’ of the needle that occurs as it is inserted into the tissue. The less deflection you can achieve, the more accurate your injection will be.

Question 12

What are some factors that cause needle deflection?

Answer 12

greater bevel angle, smaller gauge needle (smaller lumen), and longer length

Question 13

What can you do to minimize needle deflection?

Answer 13

One technique (Bi-Rotational Insertion Technique) is to rotate the needle as it’s being inserted into the tissue

Question 14

What is the purpose of aspiration?

Answer 14

it is meant to check if the needle has entered a blood vessel - since we don’t want to inject LA into a vessel you should always aspirate

Question 15

What is the most common site for a needle to break?

Answer 15

The hub

pre-bending of needle is most common cause of fracture

Question 16

What are the four parts of a cartridge?

Answer 16

Glass tube, stopper (plunger), aluminum cap, rubber diaphragm

Question 17

What purpose does Sodium (meta)bisulfite have on the injection?

Answer 17

It’s an antioxidant that protects the vasopressor from being degraded

Question 18

How long should you allow topical anesthetic to anesthetize the site of insertion before doing so?

Answer 18

at least 1 min, but 2-3 can get even better results

don’t use topical anesthetics containing alcohol

Question 19

What are the four basic steps to injection?

Answer 19

1. dry area 2. apply minimal topical anesthetic 3. pull tissue taut 4. insert/inject

Question 20

Why would you attach the needle to the syringe/cartridge AFTER inserting the cartridge?

Answer 20

The cartridge-penetrating end of the needle may break or bend if you’re also trying to harpoon the cartridge in the syringe

Question 21

If you get a positive aspiration, what is the next step?

Answer 21

Positive aspiration means you’re in a vessel, so retract the needle and insert again

Question 22

What should you do in the event of any complication associated with LA injection?

Answer 22

Take careful note of it in the pts chart

Question 23

What injection has the highest frequency of needle fractures?

Answer 23

IA block (90% of needle breaks are during this injection)

Question 24

The longer length of time that prolonged anesthesia/paresthesia persists raises potential for ____________.

Answer 24

complications

Question 25

What can cause paresthesia?

Answer 25

mechanical trauma to the nerve, or the injection contaminated by alcohol

Question 26

What is an adverse effect seen with infraorbital nerve blocks?

Answer 26

facial nerve paralysis

Question 27

What is trismus?

Answer 27

prolonged, titanic spasm of jaw muscles that restrict normal opening of the mouth (locked jaw)

Question 28

What causes soft tissue injury?

Answer 28

self inflicted injury caused by the patient inadvertently chewing or biting while anesthetized

Question 29

What is a hematoma, and in what tissue is it more likely to occur?

Answer 29

It’s when a blood vessel (arteries more common) is inadvertently nicked during LA injection. it’s more common to occur in soft tissues away from any hard tissue

Question 30

How can you manage a hematoma in the clinic?

Answer 30

DO NOT apply heat, apply ice instead, avoid dental work until problem resolves, and don’t release pt until hematoma stops bleeding

Question 31

What causes the burning upon injection that pts can sometimes feel?

Answer 31

main cause is the acidic pH of the LA (vasopressor is acidic), but can also be caused by too rapid of injection, or alcohol contamination

Question 32

What are two reasons why you shouldn’t inject LA into infected tissue?

Answer 32

LA is less effective in infected tissue, and if flow of the LA into the tissue can transport bacteria causing the spread of infection

Question 33

How can you manage edema?

Answer 33

ensure airway is open, administer epinephrine if necessary, perform cricothyroidotomy if total airway obstruction