Techniques for local anasthesia in dentistry pdf - د.محمد رحيل

Techniques for

local anasthesia in

dentistry

Dr.Mohamed Rhael Ali

2016 - 2017

local anasthesia techniques

Topical



Infiltration

Regional (block)

Topical ( surface )

anasthesia

• Obtained by application of anasthetic agent to skin

or mucosa to anasthetize superfacial nerve ending

• Its used mainly prior to injection

• Sprays containing appropriate local anasthesia

mostly suitable prior to injection due to its rapid
onset time

Topical ( surface ) anasthesia

• Mainly used spray LA consist from

10% lidocaine

hydrochloride .

• The onset of time about

1 minute

and the duration about

10 min .

• Ointment 5% lidocaine

hydrochloride can be used for the

same purpose but it

take 3-4 minutes

to produce surface

anasthesia .

• Ethyl chloride spray

can be used to produce rapid surface

anasthesia by refrigeration , this technique used mainly
prior to incision of drainage of pus .

Infiltration anasthesia

Deposition of local anasthesia near the nerve ending by

which the LA diffuse through the tissue to reach the nerve

fibers

Subdivided in to several techniques :

a. Submucosal injection

LA solusion deposited just beneath the mucous

membrane , its suitable for soft tissue anasthetization

but

not effective for pulp anasthetization

Infiltration anasthesia

b. Supra-periosteal injection

• This technique effective in maxilla
• LA solution deposited above the periosteum
• It infiltrate through the periosteum , cortical plate ,

medullary bone and reach nerve fiber , so its used to
anasthetize dental pulp .

• This technique is the most used technique in dentistry
• LA should deposited near the root apex

Infiltration anasthesia

c. Sub-periosteal injection

• Here the LA solution deposited between the periosteum

and the cortical plate .

• Its painful technique because periosteum tense and

firmly attached to the cortical bone plate

Infiltration anasthesia

d. Intra-osseuous injection

• Rarely used technique .
• LA solution deposited within the

medullary bone .

• This procedure carried out by the use of

bone drills and needles especially
designed for this purpose .

Regional anasthesia (block)

Regional anasthesia

• Deposition of local anasthetic

solution near a nerve trunk so
producing anasthesia for area
supplied by this nerve .

• It can be used in maxilla but its

main indication in the
mandible because infiltration
technique in the mandible
mainly ineffective due to dense
cortical bone plate .

local anasthesia in maxilla

Anasthesia of upper molars teeth

• The pulp of all upper molars innervated by

branches from superior posterior alveolar nerve

(except the mesiobuccal root of first molar )

• Theses nerves also responsible for innervation of

periosteum and buccal gingiva in molars region .

• Deposition of anasthesia close to the nerve after it

leaves its bony canal will produce regional

anasthesia but its rarely used because it carries a

risk of damage to the pterygoid venous plexus

Technique for posterior superior

alveolar nerve block

• 1. partially open the patient mouth
• 2. retract the patients cheek
• 3. insert the needle into the height of the

mucobuccal fold over the second molar

• 4. Advance the needle slowly in an upward ,

inward ,and backward direction in one
movement

• 5. deposite anasthetic solution (about 1-1.8

ml) and then withdraw the syringe

Infiltration technique

1. Hold the syringe with the long axis of the

tooth

2.Insert the needle into the height of the

mucobuccal fold over the target tooth

3. Advance the needle for a few millimeters and

inject slowly about third the cartidge and then

withdraw the syringe slowly

In block technique the whole region supplied by

superior posterior alveolar nerve will be

anasthetize while in infiltration technique a

limited area of specific target tooth will be

anasthetized

Anasthesia for upper premolar teeth

• The mesiobuccal root of the upper first molar

and both premolars and buccal supporting
tissue and mucoperiosteum related to them
all are

innervated by middle superior alveolar

nerve .

• So infiltration technique to this nerve will be

sufficient to anasthetize all these structures .

Anasthesia for upper anterior teeth

The upper anterior teeth and its supporting

tissues and mucoperiosteum related to them

are innervated via anterior superior dental

nerve so infiltration technique will be sufficient

Note :

In conservative treatment the pulp only needed
to be anasthetized while in tooth extraction the

pulp , bone ,periosteum and the gingiva (labial

and palatal ) should be anasthetized

Anasthesia for palatal mucosa

Palatal mucosa are tense and closely attached

to the underlying bone so :

• Injection will need great pressure
• Injection usually painful . pain can be reduced by

inserting the needle with the bevel facing the bone
and as near as possible at right angle to the vault of
the palat

Palatal anasthesia can be achieved by block injection:

to the

greater palatine nerve

in the posterior part of hard palat

distal to the second molar about 1 cm toward the midline

and

nasopalatine block

in the anterior part of hard palat

(incisive foramen) in the midline of the palate ,about 1 cm

posterior to the maxillary central incisor.

by infiltration :

in which the solution is deposited in the

palatal tissue adjacent to the target tooth .

Anasthesia for palatal mucosa

Infiltration technique for the

palat

Infra - orbital block injection

 Rarely used because infiltration technique so effective in

maxilla .

 Usually indicated when numerous extration or extensive

surgery are to be done in maxillary anterior teeth .

 Also indicated when infiltration technique precluded by

presence of infection at the injection site .

 This technique provide ansthesia for centrals, lateral

incisors,canine , premolars and supporting structures .

Techniques :

  Intra –oral

  Extra – oral

Infra - orbital block injection

Intra-oral approach :

• Most popular technique .
• Infra-orbital ridge palpated and the infraorbital notch

determined .

• Infrorbital foramen lie directly below below this notch
• lip reflectd and long needle inserted in to a depth

about 1.5-2 cm

in to the mucous membrane over

second premolar .

• About I ml of LA given

Infra - orbital block injection

• Extra oral approach

Infra - orbital block injection

Anasthesia of the upper deciduous

teeth

• Infiltration technique highly effective because

the labio-buccal bone plate are thin and
perforated by numerous vascular canals .

• Care should be taken to estimate the length

of roots and depth of injecion.

local ansthesia in mandible

• Infiltration techniques are of limited value

due to the dense cortical bone of mandible

• Block technique for inferior alveolar nerve is

the preffered technique

Boundaries of the pterygomandibular space

Inferior dental block (IDB)

• The success of this technique

depend on the accuracy of
deposition of the solution .

• This technique ansathetize the

inferior alveolar nerve and its
terminal branches (mental and
incisive nerve)

Technique for IDB

Notes

• The dimentions and shape of the mandible may vary in

patients of differing race , size , age so the width of the

ascending ramus and the position of the mandibular

foramen may vary between individuals.

• Its better to palpate the anterior and posterior border of the

ascending ramus by the thumb and index fingers and the

needle directed midway between the two fingers

• Bilateral IDB should be avoided as possible ( patient feel

discomfort , difficulty in swallow and to avoid self injury to

the anasthetized tissues)

• Lingual nerve can be asnasthetized by infiltration technique

by injection of about 0.5 ml of the solution in the lingual

sulcus adjacent to the target tooth

Long buccal nerve block

• Can achieved by sub-

mucosal injection of local
ansthesia just posterior and
buccal to the last molar .

• Infiltration technique

achieved by deposition of
the solution in the muco-
buccal fold adjacent to the
target tooth .

Notes

• When the long buccal nerve anasthetized the

patient rarely experiences any symptoms due
to the small size of the anasthetized area .

• The depth of penetration of the needle not

more than 2-4 mm .

Anasthesia of the lower anterior teeth



lower anterior teeth usually have innervation from

both sides of dental nerve by anastomosing its
terminal branches at these region.

Unilateral IDB usually not enough

Infiltration technique is effective because the labial

bone plate at this region are thinner and more
porous than other parts of mandible .

Mental nerve block

• Can be used to anasthetize the premolars,

canine and the incisors of that side

Anasthesia of the lower deciduous teeth

 Infiltration technique highly effective

Thank you for listening , please watch

these videos :

https://www.youtube.com/watch?v=jHlFBg_u_70

And

https://www.youtube.com/watch?v=wL5m0fE9C6I