Various techniques of achieving

LOCAL ANESTHESIA

Various techniques of achieving

LOCAL ANESTHESIA

LOCAL ANESTHESIA

Local anesthesia is defined as a loss of sensation in a circumscribed area of the body caused by a depression of excitation in nerve ending or an inhibition of the conduction process in peripheral nerves.

- Malamed 1980

Different techniques of achieving LA

Local infiltrationField blockNerve blockIntraligamentryIntraseptalIntrapulpalIntraosseous injectionJet injector Computer controlled local anesthetic delivery systemElectronic dental anesthesiaTopical anesthesia

Local infiltrationIn local infiltration, small terminal nerve endings in the area of the surgery are flooded with local anesthetic solution, rendering them insensitive to pain or preventing them becoming stimulated & creating an impulse.

Incision is made into the same area in which the LA has been deposited.

Field block Method of securing regional anesthesia

consisting of depositing a suitable LA solution in proximity to the large terminal nerve branches so that the area to be anesthetized is circumscribed to prevent the central passage of afferent impulses

Incision is made into an area away from the site of injection

Nerve block

Method of securing regional anesthesia by depositing LA solution within close proximity to a main nerve trunk

Usually at a distance from the site of operative intervention

Periodontal ligament injection

Indications1. Pulpal anesthesia of one or two teeth in a quadrant

2.Treatment of isolated teeth in mandibular quadrant

3. Patient for whom residual soft tissue anesthesia is undesirable

4. Situations in which regional block is contraindicated

Contraindications1. Infection or inflammation at the site of injection

2. Primary teeth when the permanent tooth bud is present

3. Patient who requires a “numb” sensation for psychological discomfort

Intraseptal injection

IndicationsWhen both haemostasis & pain control are desired for soft tissue & osseous periodontal treatment

Contraindications

Infection or severe inflammation at

the site of injection

Intrapulpal injection

Deposition of LA directly into the pulp chamber of a pulpally involved tooth provides effective anesthesia for pulpal extirpation & instrumentation where other techniques have failed.

Intraosseous injection

Indications

Pain control for dental treatment on single or multiple teeth in a quadrant

Contraindications

Infection or severe inflammation at

the site of injection

Jet injector

Principle- based on principle that liquid

forced through very small openings, called

jets, at very high pressure can penetrate intact

skin or mucous membrane

The primary use of jet injector is to obtain

topical anesthesia before the insertion of a

needle

In addition it may be used to obtain mucosal

anesthesia of palate.

Advantages

1. Does not require use of needle

2. Delivers very small amount of LA

3. Used in lieu of topical anesthesia

Disadvantages

1. Is inadequate for pulpal anesthesia or regional anesthesia

2. May damage periodontal tissue

3. Many patients dislike the feeling accompanying use of the jet injector

4. Post-injection soreness of soft tissue may develop

Computer-controlled local anesthetic delivery

system

The system enables a dentist or hygienist to

accurately manipulate needle placement with

fingertip accuracy and deliver the LA with a

foot-activated control

Disadvantages

1. Need for additional armamentarium

2. Increased cost

Advantages

1. Precise control of flow rate & pressure, hence a more comfortable injection

2. Increased tactile feel

3. Non-threatening

4. Automatic aspiration

5. Rotational insertion technique minimizes needle deflection

Electronic Dental Anesthesia

The method of achieving local anesthesia involves the use of the principle of transcutaneous electrical nerve stimulation {TENS} which has been used for the relief of pain

Indications

1. In patients with needle phobia

2. Ineffective LA

3. Instances where LA cannot be administered

Contraindications1. Cardiac pacemakers

2. Neurological disorders

3. Pregnancy

4. Very young pediatric patients

5. Older patients with senile dementia

Topical anesthesia

Anesthesia obtained by the application of a suitable agent to an area of either the skin or mucous membrane which it penetrates to anesthetize superficial nerve endings

Spray

Ointments & jelly

EMLA (Eutectic mixture of LA)

References:-

Shobha tandon –Text book of pedodontics, 1st edition 2001, published by Divyesh a kothari, page no.464-469

Stanley F. Malamed –Handbook of local anesthesia, fifth edition, published by Elsevier, page no. 255-268 & 352-358

Goran koch & Sven poulsen –Pediatric dentistry a clinical approach, 1st edition 2001, page no. 155-159

Richard R. welbury –Paediatric dentistry, second edition, page no. 78