Chapter 9: Local Anesthetic Delivery Devices

Who originated the dental syringe?

Ie. Breech-loading and cartridge-types

Harvey Cook

What was the first aspirating syringe?

Ie. Harpoon-type

Novocol

What are the components of the armamentarium in LA?

Mouth mirror

Recapping/needle disposal devices

Syringe

Cotton pliers/hemostat

Gauze Squares

Cotton Swabs

Needles of appropriate gauge and length

Cartridges of drugs

Topical anesthetic agents

What part of the dental syringe is at A?

Thumb ring

What part of the dental syringe is at B?

Finger grip

What part of the dental syringe is at C?

Spring

What part of the dental syringe is at D?

Guide Bearing

What part of the dental syringe is at E?

Piston

What part of the dental syringe is at F?

Harpoon

What part of the dental syringe is at G?

Syringe barrel

What part of the dental syringe is at H?

Needle adaptor

What part of the LA needle is at A?

Needle shaft

What part of the LA needle is at B?

Beveled tip

What part of the LA needle is at C?

Cartridge penetrating end

What part of the LA needle is at D?

Syringe adaptor

What part of the LA needle is at E?

Hub

What part of the LA needle is at F?

Needle cap

___________ is the diameter of the lumen of a needle.

Guage

True or False: The smaller the gauge, the smaller the diameter of the lumen.

False

Are the following benefits of using a smaller or larger gauge:

-Less deflection

-Greater accuracy

-Decreased needle breakage

-Aspiration easier

-More reliable

Larger

What is the number for the preferred gauge?

25

What color is the preferred gauge (25)?

Red

True or False: 30-gauge needle has a smaller internal diameter than a 25-gauge needle.

True

What percentage of positive aspirations are achieved with 25-gauge needles?

100%

What percentage positive aspirations are achieved with a 27-gauge needle?

87%

What percentage of positive aspirations are achieved with a 30-gauge needle?

2%

A 25-gauge needle should be used when there is a greater risk of positive aspiration. What injection sites have the greatest risk of positive aspirations?

All of these are correct.

What color is a 27-gauge needle?

Yellow

What is the length of a long needle?

1 5/8 inches or 40mm, average length 32mm from tip to hub

What is the length of the short needle?

1 inch or 25mm, average length is 20mm

What gauge is considered to be an ultrashort needle?

30-gauge

Use the term _______________ when referring to a long needle in front of a patient.

Regular

Which of the following statements is true with respect to the gauge of the needle?

They are ranked from largest to smallest: 25, 27, and 30 gauges.

Why should the needle never be inserted up to its hub?

Increases potential for needle breakage

Where is the weakest point of a needle?

At the hub

A needle should be changed after how many penetrations?

3-4

The _________ method is a simple one-handed method of recapping a contaminated needle.

Scoop

What part of the dental drug cartridge is at A?

Cylindrical glass tube

What part of the dental drug cartridge is at B?

Stopper

What part of the dental drug cartridge is at C?

Aluminum cap

What part of the dental drug cartridge is at D?

Diaphragm

What are the contents of anesthetic cartridges?

Distilled water

LA drug

Vasoconstrictor drug (if present)

Sodium Bisulfite (preservative with vasoconstrictor)

Sodium chloride (Isotonicity)

What causes large bubbled in drug cartridges?

Freezing

What causes an extruded stopper of a drug cartridge?

Prolonged storage in a disinfectant or freezing

What causes a corroded cartridge cap?

Immersion in disinfecting solution- Do not use!

What causes rust on the cap?

A cartridge in the container has broken or leaked- Do not use cartridges with rust

Why would the syringe be leaking during an injection?

Improper needle penetration in the diaphragm

What might be a reason for burning upon injection?

This may be a normal response to the pH of a drug.

True or False: The cartridge should be warmed prior to use.

False

CCLAD stands for ________________.

Computer controlled LA devices.

What is the delivery rate for Block technique or Intraosseous?

0.020mL/sec

What is the delivery rate of infiltrations?

0.017mL/sec

What is the delivery rate of a palatal injection?

0.008mL/sec

What is the delivery rate of a PDL?

0.007mL/sec

Which one of the following statements is correct?

The standard aspirating syringe is designed to provide negative pressure on aspiration similar to the self-aspirating syringe.

Which one of the following is correct when addressing OSHA requirements for medical device safety in dentistry?

Uncontaminated needles may be bent.

In comparing a 25-gauge needle with a 30-gauge needle, the 25-gauge needle:

1. Has better aspiration

2. Breaks more easily

3. Is less comfortable than the 30-gauge

4. Has a small diameter

5. Can be used in highly vascular areas.

1, 5

Long needles are approximately ___________ long.

32-36mm

When a stopper is extruded, what has likely caused the problem?

Freezing occurred during shipping and handling.

During an infiltration injection, you give the patient three stopper-widths of LA. How much solution have you injected into the patient?

06mL

What substance is used as the preservative for epinephrine in LA cartridges?

Sodium Bisulfite