This document provides information on various topics related to local anesthesia. It begins with definitions of pain and local anesthesia. It then discusses the constituents of local anesthetic solutions, including local anesthetic agents, vasoconstrictors, and other components. Various techniques for local anesthesia are covered, including local infiltration, field block, nerve block, and others. Specific injection techniques for the maxilla and mandible are explained.

1. Presented By
JEAN MICHAEL
Batch 4/RDC
JM 1

2. PAIN
• It is defined as an unpleasant
sensational experience
initiated by noxious stimulus &
transmitted over a specialized
neural network to CNS where
it is interpreted as such
JM 2

3. LOCAL ANESTHESIA
Transient loss of sensation in a circumscribed
area of the body caused by a depression of
excitation in nerve endings or an inhibition of
the conduction process in peripheral nerves.
JM 3

4. CONSTITUENTS OF LOCAL
ANESTHETIC SOLUTION
1. Local anesthetic agent
2. Vasoconstrictors
3. Reducing agents
4. Preservatives
5. Fungicide
6. Vehicle
JM 4

5. Local Anesthetic Agent
ESTERS
Esters of BENZOIC ACID
Cocaine, Butacaine, Benzocaine, Tetracaine etc
Esters of PARA-AMINOBENZOIC ACID
Procaine, Chloroprocaine, propoxycaine etc
AMIDES
Bupivacaine, lidocaine, articaine, prilocaine
QUINOLONES
Centbucridine
JM 5

6. Vasoconstrictors
Pyrocatechin derivative
EPINEPHRINE & NOREPINEPHRINE
Benzol derivative
LEVONORDEFRINE
Phenol derivative
PHENYLEPHRINE
JM 6

7. Functions of Vasoconstrictors
• ↓ the blood flow to the injection site
• Absorption of LA into CVS is slowed leading to lower
LA level in blood
• ↓ the risk of toxicity due to LA
• ↑ the duration of action of the LA
• ↓ bleeding and are useful when increased bleeding
is anticipated
JM 7

8. • Most commonly used agent – Phenylephrine
(1:2500)
• Limit – 4 mg at a time
(Cardiac patients – 1/4th of normal dose)
• Contraindication – THYROTOXICOSIS
• If the LA solution is exposed to sunlight for a long
time before administration, vasoconstrictor in
the solution gets degraded by oxidation
JM 8

9. Reducing Agent
(Sodium metabisulphite)
Preservative
(Xylotox)
Fungicide
(Thymol)
Vehicle
(Modified Ringer’s solution)
JM 9

10. Mechanism of Action of LA
Specific Receptor Theory –
1. Displacement Of Calcium ions from the Sodium
Channel Receptor Site
2. Binding of LA molecule to this receptor site
3. Blockade of sodium conductance
4. Decrease in Sodium Conductance
5. Depression in the rate of electrical depolarization
6. Failure to attain the threshold potential level
7. Lack of development of propagated action
potentials
8. Conduction Blockade
JM 10

11. Biotransformation
(Alteration of the drug within the living organism)
• Ester LAs are hydrolyzed in plasma by the enzyme
pseudo-cholinesterase. The one that undergoes
hydrolysis readily is the least toxic. Allergic reactions
are mostly due to the major metabolic product –
para-aminobenzoic acid
• Amide LAs are primarily metabolized in the liver.
Liver function and hepatic perfusion significantly
influence the rate of biotransformation.
JM 11

12. Techniques of Local Anesthesia
JM 12

13. THE TRIGEMINAL NERVE
JM 13

14. Local Infiltration
• Small terminal nerve endings in the area of surgery are
flooded with LA solution rendering them insensitive to pain.
In this method, incision is made through the same area in
which the solution has been deposited.
• This technique is usually successful for treatment of
mandibular deciduous canines, incisors and even in molars.
JM 14

15. Field Block
• Here the LA solution is deposited in proximity to the large
terminal nerve branches so that the area to be anesthetized is
circumscribed to prevent the central passage of afferent
impulse
• Maxillary injections administered above the apex of the tooth
can be termed field blocks
JM 15

16. Nerve Block
• Method of securing local analgesia in which suitable local
anesthetic solution is deposited within close proximity to the
main nerve trunk, thus preventing nerve impulses from
travelling centrally beyond that point.
JM 16

17. Other Techniques
• Intraligamentary
• Intraseptal
• Intrapapillary
• Intrapulpal
JM 17

18. The child should never see the injection needle
This creates anxiety and fear towards dental treatment
JM 18

19. Keep the syringe away
from the Line of sight
of the patient
JM 19

20. Maxillary
Injection
Techniques
JM 20

21. • Supraperiosteal (Local infiltration)
• Periodontal Ligament Injection
• Intraseptal Injection
• Intraosseous
• Posterior Superior Alveolar Nerve Block
• Middle Superior Alveolar Nerve Block
• Anterior Superior Alveolar Nerve Block
• Greater Palatine Nerve Block
• Nasopalatine Nerve Block
• Maxillary Nerve Block (Infraorbital Nerve Block)
JM 21

22. Supraperiosteal Injection
• Most frequently used technique for obtaining
pulpal anesthesia in maxillary teeth
• Indicated whenever dental procedures are
confined to only one or two teeth
JM 22

23. Nerves Anesthetized
Large terminal branches of dental plexus
Areas Anesthetized
• The entire region innervated by the large
terminal branches of dental plexus
1. Pulp and root area of the tooth
2. Buccal periosteum
3. Connective tissue
4. Mucous membrane
JM 23

24. INDICATIONS
• Pulpal anesthesia of the maxillary teeth when
treatment is limited to only one or two teeth
• Soft tissue anesthesia when indicated for
surgical procedures in a circumscribed area
CONTRAINDICATIONS
• Infection or acute inflammation in the area of
injection
• Dense bone covering the apices of teeth
(maxillary central incisors and 1st molars)
JM 24

25. ADVANTAGES
• High success rates (>95%)
• Technically easy injections
• Usually entirely atraumatic
DISADVANTAGES
• Not recommended for large areas due to
1. Need for multiple needle insertion
2. Necessity to administer large total volumes
of local anesthetic
JM 25

26. TECHNIQUE
• 25 or 27 gauge needle is used
• Area of insertion – height of mucobuccal fold
above the apex of the tooth being anesthetized
• Target area – apical region of the tooth to be
anesthetized
• Landmarks
1. Mucobuccal fold
2. Crown of the tooth
3. Root contour of the tooth
JM 26

27. PROCEDURE
• Prepare the tissue at the injection site
• Orient the needle so that bevel faces the bone
• Lift the lip, pulling the tissue taut
• Hold the needle parallel to the long axis of the
tooth
• Insert the needle into the height of the
mucobuccal fold over the target tooth
JM 27

28. • Advance the needle until its bevel is at or
above the apical region of the tooth
• Aspirate 2 times
• If negative, deposit approximate 0.6 ml of LA
over 20 seconds
• Slowly withdraw the syringe
• Make the needle safe
• Wait for 3 to 5 minutes before starting the
dental procedure
JM 28

29. SUPRAPERIOSTEAL INJECTION
JM 29

30. BEVEL ORIENTATION OF NEEDLE
JM 30

31. JM 31

32. JM 32

33. MINIMAL PAIN
JM 33

34. MANDIBULAR
INJECTION
TECHNIQUE
JM 34

35. Inferior Alveolar Nerve Block
• Needle Used – 25 Gauge
• Nerves Anesthetized –
Inferior Alveolar Nerve
Lingual Nerve
• Site Of Injection –
Region where the IAN enters the mandible
through the Mandibular Foramen
• Amount of solution deposited – 1 to 1.8 ml
JM 35

36. Area anesthetized
• Mandibular teeth of the
injected side
• Body of the mandible,
inferior portion of the ramus
• Buccal mucoperiosteum, mucous membrane
anterior to the mandibular 1st molar
• Anterior 2/3rd of tongue and floor of the
mouth
• Lingual soft tissue and periosteum
JM 36

37. INDICATION
• Procedures on multiple mandibular teeth in
one quadrant
• When buccal soft tissue anesthesia (anterior
to the first molar) is necessary
• When lingual soft-tissue anesthesia is
necessary
CONTRAINDICATION
• Infection or acute inflammation in the area of
injection
JM 37

38. TECHNIQUE
• 25 gauge needle is used
• Area of insertion – Mucous membrane on the
medial side of the mandibular ramus near the
mandibular foramen
• Target area – Inferior alveolar nerve as it
passes downward towards the mandibular
foramen but before it enters the foramen
JM 38

39. • Landmarks
1. Coronoid notch
2. Pterygomandibular raphae
3. Occlusal plane of the mandibular
posterior teeth
JM 39

40. LEFT RIGHT
• Patient position – supine or semisuppine
• Operator position –
1. Right IANB – 8 o’clock position
2. Left IANB – 10 o’clock
JM 40

41. PROCEDURE
• With the left thumb, palpate the coronoid
notch
• With the same finger, pull the buccal soft
tissue laterally to gain visibility and make the
tissue taut
• The needle insertion point lies three fourths
the anteroposterior distance from the
coronoid notch to the deepest portion of
pterigomandibular raphae
JM 41

42. • Prepare the tissue of injection site
• Place the barrel of the syringe in the corner of
the mouth on the contralateral side
• Penetrate the tissue with the needle and
slowly advance till bony resistance is felt
JM 42

43. PEDIATRIC PATIENT
BELOW 6 YEARS
6 – 12 YEARS
JM ABOVE 12 YEARS 43

44. • Average depth of penetration is 20 – 25 mm
• When bone is contacted, withdraw 1 mm to
prevent sub-periosteal injection
• Aspirate
• If negative, slowly deposit 1.5 ml of anesthetic
over a period of 1 minute
• Slowly withdraw the syringe till half of its
length remains in the tissue
JM 44

45. • Re-aspirate
• If negative, deposit a portion of remaining
anesthetic (.1 ml) to anesthetize lingual nerve
• Withdraw the syringe slowly and make the
needle safe
• After about 20 seconds, return the patient to
upright or semi-upright position
• Wait for 3 to 5 minutes before commencing
the dental procedure
JM 45

46. Buccal Nerve Block
• Needle used – 25 Gauge
• Nerve Anesthetized –
Buccal Nerve (branch of anterior division of
mandibular nerve)
• Site of injection –
Mucous membrane distal and buccal to the
most distal molar tooth in the arch
• Amount of LA required - .3 ml
JM 46

47. Area Anesthetized
• Soft tissue and periosteum
buccal to the mandibular
molar teeth
JM 47

48. INDICATION
• When buccal soft tissue anesthesia is
necessary for dental procedures in the
mandibular molar region
CONTRAINDICATION
• Infection or acute inflammation in the area of
injection
JM 48

49. TECHNIQUE
• 25 Gauge long needle is recommended
• Area of insertions – mucous membrane distal
and buccal to the most distal molar tooth in
the arch
• Target area – Buccal Nerve as it passes over
the anterior border of the ramus
• Landmarks – mandibular molars &
mucobuccal fold
• Orientation of bevel – towards the bone
JM 49

50. PROCEDURE
• Operator position
Right BNB – 8 o’clock position
Left BNB – 10 o’clock position
• Patient position – supine or semisupine
• Prepare the tissue for needle penetration
• With left index finger, pull the buccal soft
tissues in the area of injection laterally to
improve visibility and make the tissue taut
JM 50

51. OPERATOR AND PATIENT POSITIION FOR BNB
LEFT RIGHT
JM 51

52. • Align the needle parallel to the occlusal plane
and buccal to the teeth and direct it towards
the injection site
• Penetrate the mucous membrane at the
injection site, distal and buccal to the last
molar
JM 52

53. • Advance the needle until mucoperiosteum is
gently contacted
• Depth of penetration – 1 to 2 mm
• Aspirate
• Slowly deposit .3 ml of LA over 10 seconds
• Withdraw the syringe slowly and immediately
make the needle safe
• Wait for approximately 1 minute before
commencing the dental procedure
JM 53

54. IANB & BUCCAL NERVE BLOCK
JM 54

55. INTRAPULPAL
INJECTION
JM 55

56. • Here local anesthetic solution is delivered
directly to the pulp using a bent needle
• mostly used to anesthetize mandibular 1st molar
which may be sometimes difficult to achieve
using other procedures like nerve blocks in case
of inflammation in the site of infection
• Advantages of Intrapulpal injection –
• Requires minimum volumes of LA solution
• Immediate onset of action
• Very few post operative complications
JM 56

57. • Nerve anesthetized –
Terminal nerve endings at the site of injection
in the pulp chamber and canals of the involved
tooth
• Areas anesthetized –
tissues within the injected tooth
INDICATION
when pain control is necessary for pulpal
extirpation or other endodontic treatment in
the absence of adequate anesthesia from other
technique JM 57

58. TECHNIQUE
• Insert a 25 or 27 gauge short or long needle
into the pulp chamber or the root canal
• Wedge the needle firmly into the pulp
chamber or root canal
• Deposit .2 to .3 ml of anesthetic solution
under pressure
• Resistance to the injection of the drug should
be felt Bend the needle, if necessary, to gain
access to the canal
JM 58

59. • When the intrapulpal injection is performed
properly, a brief period of sensitivity (ranging
from mild to very painful) usually
accompanies the injection
• Pain relief occurs immediately thereafter,
permitting instrumentation to proceed
atraumatically
• Instrumentation may begin approximately 30
seconds after the injection
JM 59

60. TOPICAL ANESTHESIA
• It is the method of obtaining anesthesia by the
application of suitable agent to an area of
either the skin or mucous membrane through
which it penetrates to anesthetize superficial
nerve endings
• It is commonly used to obtain anesthesia of
the mucosa prior to injection
JM 60

61. Topical anesthetic Sprays
Active ingredient – 10% Lignocaine Hydrochloride
Onset of Action – 1 minute
Duration of Action – 10 minutes
Available in different fruit flavors
JM 61

62. Technique
• Dry the area of application (mucous membrane)
• Spray an appropriate quantity of the solution
into a small cotton roll
• Place the cotton role on the site of injection in
the sulcus
• Wait for 1 minute before inserting the needle to
allow the topical anesthetic to act
JM 62

63. Topical Anesthetic Ointments & Jelly
• Ointments – 5% Lignocaine
(onset of action is 3-4 minutes)
• Emulsions – 2% Lignocaine
BENZOCAINE –
• Odorless white crystalline powder
(soluble in alcohol and fatty oils)
• Safe – due to its low aqueous solubility, It is
very slowly absorbed from the oral tissues and
wounds
JM 63

64. RECENT ADVANCES IN LA
JM 64

65. EMLA (Eutectic Mixture of LA)
• Mixture of LIGNOCINE & PRILOCAINE
• EMLA cream is used for numbing the skin
before inserting the needle
• It is designed to go through intact skin
• Potential for toxic effects of LA is minimal
• Use in children under 6 months is
contraindicated due to the possibility for
developing methemoglobinemia due to
prilocaine
JM 65

66. Intraoral lignocaine patch
• Contains 10% or 20% lignocaine
• Placed for 15 minutes on the buccal mucosa of
the maxillary or mandibular premolar area, 2
mm apical to the mucogingival junction
JM 66

67. Electronic Dental Anesthesia
• Uses the principle of Transcutaneous Electrical
Nerve Stimulation (TENS)
• Requires good patient co-operation
• It increases salivary blood flow
JM 67

68. Complications Of LA
(Pediatric Patient)
JM 68

69. NUMB FEELING
• Invites the possibility of an unnecessary
emotional upset of the child
How to Avoid ?
• The dentist should explain beforehand to the
child that he/she will experience the
numbness after the administration of LA
JM 69

70. LIP BITING
How to avoid ?
• Warning should be given immediately following
injection procedure. Warning should be repeated
before the child leaves the dental chair.
• Parents should also be warned about this
possible complication if not attended properly
JM 70

71. JM 71

72. Complication due to Injection of
LOCAL ANESTHETIC SOLUTION
3 TYPES –
1. Method of deposition of the drug
2. Drug dosage dependent reactions
3. Hypersensitivity reactions
JM 72

73. Method of deposition of drug
VASOVAGAL SYNCOPE
• Due to peripheral pooling of blood and
reduction in cerebral blood flow
• Rarely encountered in children due to constant
movement of extremities coupled with crying
out loud which prevents the peripheral pooling
of blood
JM 73

74. BROKEN NEEDLE
• Due to sudden movement during administration
of the LA solution
FAILURE TO ACHIEVE ANESTHESIA
• This may be due to
1. Improper Technique of administration
2. Normal anatomic Variation
JM 74

75. FACIAL NERVE PARALYSIS
• Encountered during IANB
• Due to injection of LA solution into parotid
gland
• Facial Nerve gets temporarily paralyzed
• Effects wears off over a period of time during
which the eye needs to be protected
JM 75

76. TRISMUS
• Due to trauma to muscles or blood vessels of
infra temporal fossa
• Intramuscular or supramuscular injection of
LA
• Hemorrhage
• Hematoma and scar formation
How to Avoid ?
• Avoid repeated injections or multiple
insertions into the same area
• Use only minimum effective volume of LA
JM 76

77. Drug Dosage Dependent Reactions
• At Low levels - ↑ Heart rate and Cardiac Output
• At High levels - ↓ Cardiac Output & Circulatory
Failure
• Methemoglobinemia – Caused by Benzocaine &
Prilocain
How To Avoid ?
• Use Of Aspiration Technique
• Keeping the amount of agent administered
below toxic limit
JM 77

78. CAUSES OF TOXICITY
• Use of excessive dose of LA
• Inadvertent intravascular injection
• Slow detoxification or biotransformation
• Slow elimination or redistribution
Majority of the toxic reactions to LA are
immediate, mild and transient
They can be avoided by closely monitoring
during the injection, injecting slowly and
withdrawing the needle at the first signs of an
adverse response
JM 78

79. TOXICITY DUE TO VASOCONSTRICTORS
• They causes local ischemia and thus retard
their own absorption
• Patients with ischemic heart diseases and
hypertension are at high risk of toxicity if
administrated intravascularly
JM 79

80. Manifestation Of Toxicity
•
Concentration of LA in Plasma
Cardiac Depression
• Coma
• Convulsions
• Unconsciousness
• Muscular twitching
• Visual and auditory disturbances,
light headedness, numbness of
tongue
JM 80

81. Hypersensitivity (rare)
Manifests as
• Utricaria
• Facial edema
• Breathlessness
Methyl paraben (protein) is the main allergent
• It has been replaced in recent times
JM 81

82. JM 82