XV. INSTRUMENTS USED IN THE ADMINISTRATION OF LOCAL ANESTHESIA

Types of syringes

1. non-disposable syringes

2. Disposable syringes

3. Safety syringes

4. Computer controlled local anesthetic delivery system

Types of non-disposable syringes

1. Breech-loading/ end loading, metallic, cartridge type, aspirating syringe

2. Breech-loading, plastic, cartridge type, aspirating syringe

3. Breech- loading, metallic, cartridge-type, self-aspirating syringe

4. Pressure syringe/ intraligamentary syringe

5. Jet injector

• most commonly used type of syringe in dental practice

• may be aspirating or non-aspirating

NON-DISPOSABLE SYRINGES

a thumb ring & a sharp, hook-shaped end (harpoon) is attached to the piston that penetrates the rubber silicone plunger (stopper or bung) of the cartridge which then applies negative pressure that is seen as blood within the cartridge & indicates that the needle tip has penetrated a blood vessel

Aspirating

does not contain a harpoon at the end of the piston so aspiration cannot be performed & this is the reason it is no longer acceptable in dental practice

Non-aspirating

• most commonly used non-disposable syringe in dentistny

• breech-loading: cartridge is inserted into the syringe from the side of the barrel of the syringe

• end-loading: insertion of the cartridge is from the back or end of the barrel al the syringe

BREECH-LOADING / END-LOADING, METALLIC, CARTRIDGE-TYPE ASPIRATING SYRINGE

plastic material is reusable, autoclavable, and can withstand chemica sterilization

BREECH-LOADING, PLASTIC, CARTRIDGE-TYPE, ASPIRATING SYRINGE

uses the elasticity of the rubber diaphragm (semi-permeable) of the cartridge to obtain the necessary negative pressure that is required for aspiration

BREECH-LOADING, METALLIC, CARTRIDGE-TYPE, SELF-ASPIRATING SYRINGE

pen-type or piston-type syringe that is used for injections into the periodonta ligament (intraligamentary injection technique)

PRESSURE SYRINGE / INTRALIGAMENTARY SYRINGE

Advantage/disadvantage of PRESSURE SYRINGE / INTRALIGAMENTARY SYRINGE

• advantage: achieves single tooth pulpal anesthesia in the mandible without the need for a complete inferior alveolar nerve blockdisadvantage: tendency to inject too rapidly due to ease of administration

new approach to parenteral injection that uses needle-less injection which is based on the principle that liquids forced through very small openings (jets) at very high temperatures can penetrate intact skin or mucous membranes

JET INJECTOR

first fundamental change in the basic principles of injection since the introduction of hypodermic needles in 1853

Jet injector

plastic, non-cartridge containing syringes that contains a Luer-Lok screw

Disposable syringes

on needle attachment with no aspirating tip and are readily available in a variety of sizes with an assortment of needle gauges

Disposable syringe

anesthetic is withdrawn from a vial or cartridge

Disposable syringe

aspiration may stil be done, but itis difficult with the absence of a thumb ring

Disposable syringes

can be used for intraoral injections, but iht is frequently utilized for intravenous (MV & intramuscular (IM) injections

Disposable syringe

contains a syringe body assembly, plunger assembly, and a safety mechanism patient's tissue which prevents any accidental needle-stick injuries wherein a sheath "locks" over the needle once it is retracted & removed from the patient tissue which prevents any accidental needle stick injuries

Safety syringe

single-use items, but it allows reinjection

Safety injections

further training may be needed when shifting from traditional methods to the use of safety needles

Safety syringe

foot activated delivery of solution using fingertip precision that is designed to improve ergonomics and precision of injection techniques

COMPUTER CONTROLLED LOCAL ANESTHETIC DELIVERY SYSTEM (C-CLAD)

inability to simultaneously control the variables of drug infusion & the movemen of the penetrating needle can compromise the injection technique/s

COMPUTER CONTROLLED LOCAL ANESTHETIC DELIVERY SYSTEM (C-CLAD)

pre-sterilized, stainless steel disposable needles of different sizes (thickness & length)

Needle

needle of choice will depend on the procedure to be done & the operator's preference

Needle

Needle gauge

Needle length

needle gauge: thickness / diameter of a needle in which a larger (higher) number will indicate a smaller (lower) intemal diameter of the needle & vice-versa

needle length (intraoral injections): measured from hub to tip and can be extra short (about 10mm / 0.4"). short (approximately 20mm / 0.8"). or long (about 32mm / 1.25"): minor variations may occur depending on the manufacturer

____ mL cylindrical glass tube containing a local anesthetic that is covered at one end with an aluminum cap for the rubber diaphragm & the opposite end has a silicon rubber plunger

1.8-2.2mL

1.8 -2.2mL cylindrical glass tube containing a local anesthetic that is covered at one end with an aluminum cap for the rubber diaphragm & the opposite end has a silicon rubber plunger (stopper or bung)

DENTAL CARTRIDGE

incorrectly referred to as "CARPULE" wWhich is the registered trade name of the dental cartridge introduced in 1920 by Cook-Waite Laboratories

DENTAL CARTRIDGE

Should not be soaked in any solution to disinfect the cartridge: this would affect the semi-permeable rubber diaphragm since it will allow diffusion of the solution thereby contaminating it

DENTAL CARTRIDGE

must not be soaked in warm water in an attempt to slightly heat the anesthetic: the temperature may exceed the noral body temperature & result in a burning sensation upon its administration or infiltration

DENTAL CARTRIDGE

cartridge may be cleaned with alcohol wipes to maintain asepsis if deemed necessary

DENTAL CARTRIDGE

storage should be at room temperature, away from direct sunlight, & preferably in its original container

DENTAL CARTRIDGE

Components of a local anesthetic solution

1. Local anesthetic drug

2. Sodium chloride

3. Sterile water/distilled water

4. Vasopressor/ vasoconstrictor

5. Sodium bisulfite

6. Methylparaben

acts as a blockade of nerve conductior

LOCAL ANESTHETIC DRUG

3 CATEGORIES OF LA. BASED ON DURATION OF PULPAL ANESTHESIA

1. Short-acting

2. Intermediate-acting

3. Long-acting

approximately 30 minutes without a vasoconstrictor

SHORT-ACTING:

Short acting lidocaine 2%

• Xylocaine

• Alphacaine

• Octocaine

Short acting of mepivacaine 3%

• Carbocaine

• Arestocaine

• Isocaine

• Polocaine

• Scandonest

Short acting of prilocaine 4%

Citanest

approximately 60 minutes with a vasoconstrictor, except for Prilocaine 4% when it is administered as a nerve block

INTERMEDIATE-ACTING

Intermediate acting

• Lidocaine 2% w/ 1:50,000 epinephrine; Lidocaine 2% w/ 1:100,000 epinephrine

• Mepivacaine 2% with 1:20,000 levonordefrin

• Prilocaine 4% (as nerve block); Prilocaine 4% with 1:200,000 epinephrine

• Articaine 4% wl 1:100,000 epinephrine: Articaine 4% w/ 1:200,000 epinephrine (Septocaine, Zorcaine, Articadent)

approximately 90 minutes with a vasoconstrictor

Long-acting

Long-acting

Bupivacaine 0.5% with 1:200,000 epinephrine (Marcaine)

used for the isotonicity of the solution

Sodium chloride

inert ingredient that functions to provide volume

STERILE WATER/ DISTILLED WATER

• increases depth & duration of anesthesia

• decreases absorption of the local anesthetic & vasopressor

• included in most brands used in dentistry, but are absent in some brands as well

VASOPRESSOR / VASOCONTRICTOR

• sodium metabisulfite (most common)

• acts as an preservative and antioxidant in cartridges containing vasopressors the pH level (acid) tor "older cartridges compared to a newer / fresher cartridge

• burning sensation on administration can be attributed when sodium bisulfite lowers

Sodium chloride

Most common sodium

Sodium metabisulfite

• used as a bacteriostatic agent

• no longer included for single-use dental cartridges since 1984, but is present in a/l multidose vials of injectable drugs

METHYLPARABEN

Refers to a thin colored band located near the rubber silicone plunger at the end of the dental cartridge

COLOR CODING OF LOCAL ANETHESTIC CARTRIDGES

Color of Articaine HCL 4% with epinephrine 1:100,000

Gold

Color of Bupivacaine 0.5% with epinephrine 1:200,000

Blue

Color of Lidocaine HCL 2%

Light blue

Color of Lidocaine HCL 2% with epinephrine 1:50,000

Green

Color of Lidocaine HCL 2% with epinephrine 1:100,000

Red

Color of Mepivacaine HCL 3%

Tan

Color of Mepivacaine HCL 2% with levonordefrin 1:20,000

Brown

Color of Prilocaine HCL 4%

Black

Color of Prilocaine HCL 4% with epinephrine 1:200,000

Yellow

Color of Articaine HCL 4% with epinephrine 1:200,000

Silver