local anesthesia

1. LOCAL ANESTHESIA
Dr.MOHAMED HARIS.P.M
READER
MALABAR DENTAL COLLEGE

2. CONTENTS
INTRODUCTION
TERMINOLOGIES
HISTORY
CLASSIFICATION
IDEAL PROPERTIES
MECHANISM OF ACTION
COMPOSITION
ARMAMENTARIUM
TECHNIQUES
COMPLICATIONS AND ITS MANAGEMENT
LOCAL ANESTHESIA IN PERIODONTICS
FUTURE TRENDS IN PAIN CONTROL
CONCLUSION

3. INTRODUCTION
•Anesthesia - Greek word - ( An - without, Aisthesis - perception)
It has traditionally meant the condition of having the perception of pain and other
sensation blocked.
Allows the patient to undergo surgery and other procedures without distress and
pain they would otherwise experience.
The word Anesthesia was coined by Oliver Wendell Holmes in 1846.
Anesthesia in dentistry has been historically office based.

4. •Most patients seek dental treatment either for the relief of pain or in the hope of
avoiding it at a later date.
•Mastery of pain management has proven to be an essential pre-requisite to the
provision of a high standard of dental care.
Local anesthesia is the safest and the most effective drug
available for the prevention and management of pain (pain
most fear some entity in dental office).

5. TERMINOLOGIES
•Analgesia - loss of pain sensation unaccompanied by loss of other forms of
sensibility.
•Anesthesia - loss of all forms of sensation including pain, touch, temperature
and pressure perception and may be accompanied by loss of motor function.
•General anesthesia - reversible loss of all sensation and consciousness.
•Local anesthesia – Loss of sensation in a circumscribed area of the body
caused by a depression of excitation in the nerve endings or an inhibition of the
conduction process of peripheral nerve.

6. HISTORY
• In 1860 Albert Nieman in Germany introduced the first local anesthestic
agent named cocaine, isolated from cocoa leaves.
•The very first clinical use of cocaine was done in 1884 by Sigmund Freud
who used it to wean patients from morphine addiction.
• It was Freud and his colleague Karl Koller who first noticed its anesthetic
effect.

7. •In Novemeber 1884 William Burke was the first to practice Nerve block.
•Schleich and Reclus developed and practised infitration anesthesia.
•In 1943 LOFGREN invented the first modern local anesthetic agent Lidocaine
(trade name Xylocaine).
•Braun increased LAs duration and reduced its toxicity, first by using troniquet
and later added epinephrine to the solution.
•Lidocaine is still the most widely used local anesthesia today.

8. ADVANTAGES
• Patient awake and co-operative
• Little distortion of normal physiology- minimal risk to the patients
• Low mortality
• Patient can leave un-escorted
• No additional trained personnel
• Techniques not difficult to master
• Low failure rates
• cost effective

9. INDICATIONS
• Extraction of teeth
• Alveolplasty and alveolectomy
• Incision and drainage of abscesses
• Cavity preparation especially in deeper painful cavities
• Pulp procedures like pulpotomy and pulpectomy
• Treatment of trismus
• Periodontal surgery and gingival surgery

10. CONTRAINDICATIONS
• Fear and apprehension
• Local infection
• Allergy to components of local anaesthetic solution
• Patient below age of reasoning
• Un co-operative patient (eg. mentally challenged)
• Major oral surgery
• Anomalies of nerve supply

11. CLASSIFICATION
1.Based on the potency and duration of action:
• Injectable
a) Low potency and short duration.
E.g.: procaine and chloroprocaine
b) Intermediate potency and duration
E.g.: Lignocaine and prilocaine
c) High potency and long duration
E.g.: Tetracaine, bupivicaine, Ropivicaine and dibucaine
• Surface anesthetics
a) Soluble E.g.: Cocaine, lignocaine, tetracaine
b) Insoluble Eg: Benzocaine, Oxathezine

12. 2.Based on Chemical
Composition
Ester
Benzoic Acid
Esters
Butacaine,
Cocaine,
Benzocaine,
Hexylcaine,
Piperocaine,
Tetracaine
Para
aminobenzoic
acid esters
Procaine
(Novocain)
Propoxycaine
Chloroprocaine
Non Ester
group
Amide
Bupivacaine ,
Etidocaine,
Lidocaine,
Mepivacaine,
Prilocaine,
Articaine
Quinoline
Centbucridine

13. 3.Based on biological site of action
•Class A-Agents acting at receptor site on the external surface of the nerve
membrane.
E.g.: Tetrodotoxin
•Class B- receptor site on the internal surface of nerve membrane.
E.g.: Lidocaine
•Class C- receptor independent physiochemical mechanism.
E.g.: Benzocaine
• Class D- combination of receptor and receptor independent mechanism.
E.g.: Atricaine, Lidocaine, mepivicaine

14. Basic structure of local anesthetics
Local anesthetic drugs are weak organic bases and are insoluble in water.
They can be converted into soluble salts, usually the hydrochlorides
Local anesthetic molecule consist of :
• Lipophilic part- It constitutes the major bulk of molecule. It is aromatic in
nature derived from benzene, aciline or thiopene.
• Hydrophilic part-It is an amino derivative of ethyl alcohol or acetic acid.
Local anesthetic agents lacking this part are said to have good topical anesthetic
action. E.g.: Benzocaine.
• Intermediate hydrocarbon chain-It mainly consists of ester group or an
amide group based on which properties vary.

15. Desirable properties of an ideal local anesthetics
• Non-irritant , Non-Antigenic and Non-allergic
• Anesthesia should be completely reversible
• Minimal systemic toxicity
• Effective through topical application and Injection
• Highly Potent ,rapid action, adequate duration of anesthesia
• Stable solution and Sterilizable
• Administered with other agents
E.g.: Vasoconstrictors without loss of properties

16. Mechanism of action
• Displacement of Ca ions from the nerve receptor site
• Binding of local anesthetic molecule to this receptor site
• Blockade of the sodium channel
• Decrease in sodium conductance
• Depression of rate of electrical depolarization
• Failure to achieve threshold potential level
• Lack of development of propagated action potential
• Conduction blockade

17. THEORIES ON LOCAL ANESTHETIC ACTION
•Acetyl choline theory
•Calcium displacement theory
• Surface charge theory
•Membrane expansion theory
•Specific receptor theory

18. Acteyl choline theory
 Stated that acetyl choline was invloved in nerve conduction in addition to its
role as a neurotransmitter.
 No evidence that acetyl choline was involved in neural transmission.
Calcium displacement theory
 Stated that LA nerve block produced by calcium ion displacement from some
membrane site that controlled permeability of Na.
 Varying the con. of Ca ions bathing a nerve does not affect LA potency.

19. Surface charge theory
• LA acts by binding to the nerve membrane and changing the electric potential at the
membrane surface.
• Cationic molecules binds, make membrane potential +ve Increase threshold ,reduce
excitability.
• Conventional LA acts within the nerve membrane channels rather than at the
membrane sites.
• Cannot explain activity of uncharged anesthetic molecules (BENZOCAINE).

20. Membrane expansion theory
• LA molecules diffuse to the hydrophobic regions of the excitable membranes & expand
some critical regions,thus preventing the increase in permeablity of Na ions.
• However there is no direct evidence that nerve conduction is entirely blocked by
membrane expansion per se.

21. Specific receptor theory
• Most favoured theory
• Proposes that local anesthetics act by binding to specific receptors on the
sodium channels
• The action of drug is direct
• Once LA has gained access to the receptors, permeability to sodium ions is
decreased or eliminated and nerve conductance is interrupted.

22. COMPOSITION OF LOCALANESTHETICS
• Local anesthetic agent
• Vasoconstrictor
• Reducing agent
• Preservative
• Fungicide
• Salts
• Vehicle

23. LOCAL ANESTHETIC AGENT
Most important constituent.
A) Lidocaine Hydrochloride:
• Chemical Formulae: 2-Diethylamino-21,61-acetoxylidide hydrochloride
• Metabolism: In liver by microsomal fixed Function oxidases to
monoethyl glycerine & xylidide. Xylidide is a local anesthetic &
potentially toxic.
• Excretion: Excretion is via kidney.
• Onset of action: Rapid, 2 to 3 minutes.
• Ideal dental concentration: 2%
• pH of the plain solution : 6.5
• pH of vasoconstrictor containing solution : 5.5

24. VASOCONSTRICTOR
These are drugs that constrict blood vessels and thereby control tissue perfusion.
They are added to the local anesthetics solution to counteract the agents vasodilating
actions.
Vasoconstrictors are highly important for the following reasons:
• By vasoconstricting blood vessels, the vasoconstrictors decrease the blood flow to the
site of injection.
• Absorption of local anesthetic agent into the blood stream is slowed, thereby
producing low level in blood.
• Lower levels of anesthetic decrease the risk of overdose reaction.
• Higher concentration of Local anesthetic agent remains in and around the nerve for
longer period, thereby increasing the duration of action.
• Minimizes the bleeding at the site of administration.

25. • Most commonly used vasoconstrictor is adrenaline
• concentration of 1:100,000 to 1:200,000
• recommended dose of adrenaline is 0.3mmg

26. CONTRAINDICATIONS OF VASOCONSTRICTORS
• High blood pressure
• Cardiovascular disease
• Hyperthyroid patients

27. Reducing Agent
Vasoconstrictors in local anesthetic are unstable in the solution form and may
oxidize, especially on prolonged exposure to sun. 0.5 mg/ml of sodium bisulfite is added
as a reducing agent. It competes for the available oxygen in the vial.
Preservative
It is added to maintain the stability of the solution. Methyl paraben 1 mg/ml is added
to the solution in order to give it an extended shelf life.
Fungicide
Small quantities of thymol is added
Salts
Sodium chloride is added to make the solution isotonic
Vehicle:
Anesthetic agent and other constituents of the vial are dissolved in distilled water which is
used as a vehicle for making the solution

28. PROCAINE HCl
 Because of its vasodilating properties it is used in immediate intraarterial
injection.
 Allergy is more common than amide group
 Maximum Recommended dose – 1000mg
 Onset of Action – 6 to 10 min
 Half Life – 6 min
Local Anesthetic Agents – Ester Group

29. PROPOXYCAINE HCL
 Propoxycaine was combined with procain in solution to provide
 more rapid onset and more profound and long lasting anesthesia
 Onset of action = rapid ( 2 to 3 min )
 This combination is recommended when amides are contraindicated
(0.4% propoxycaine/2% procaine ) 1:30,000 norepinephrine
 Provides 40 min of pulpal anesthesia and 2 to 3 hrs of soft tissue
anesthesia
 MRD = 6.6 mg/ kg

30. AMIDES TYPE LOCALANESTHESIA
LIDOCAINE HCL
 Lignocain possesses significant more rapid onset of action(2 to 3 min)
produces more profound anesthesia (~90min) long duration of action and
has a great potency.
 Allergy is very rare it is its major clinical advantage.
 Most widely used anesthetic represents GOLD STANDARD drug to
which all new LA are compared
 2% lidocain HCL with or with out vasoconstrictor
 MRD= 7.0mg/kg of body weight
 Not to exceed 500mg Half life: ~90 mins

31. MEPIVACAINE HCL
 Pulpal anesthesia= 20 to 40 min
 Onset of action = rapid (1 to 2 min)
 Effective dental concentration=3%
 Anesthetic half life = 1.9 hrs
 MRD= 6.6mg/kg of body weight
 Mild vasodilatation properties provides a longer duration of
anesthesia

32. ARTICAINE HCl
 Potency - 1.5 times that of lidocaine,1.9 times that of procaine
 Toxicity – similar with lidocaine and procaine
 Onset of action - 1 – 3 min.
 Anesthetic half life – 0.5 hrs.
 MRD – 7.0 mg / kg bd.wt
 Articaine is able to diffuse through soft and hard tissues more rapidly than
other local anesthetics.
 Paresthesia.
 Caution in hepatic, cvs diseases.

33. BUPIVACAINE HCl
 Potency – 4 times that of lidocaine, mepivacaine, and prilocaine..
 Toxicity – 4 times less than that of lidocaine and mepivacaine.
 Vasodialation is more than that of lidocaine, mepicaine, and prilocaine.
 Onset of action – 6 – 10 min.
 Anesthetic half life – 2.7hrs.
 Effective dental conc. – 0.5%
 MRD = 1.3 mg/ kg body.wt
 Not to exceed 90mg

34. ETHIDOCAINE HCL
 Potency – 4 times that of lidocaine.
 Toxicity – 2 times as toxic as lidocaine after subcutaneous administration.
 4 times as toxic as lidocaine after i.v. administration.
 Onset of action – 1.5 – 3 min.
 Anaesthetic half life – 2.6 hrs.
 MRD = 8.0 mg / kg bd.wt
 Up to 400mg

35. TOPICALANESTHETICS
 Benzocaine – eg : Hurricaine, Super Dent, Topex.
 Cocaine HCl - not recommended.
 Dyclonine HCL – 0.5%
 EMLA - lidocaine 2.5% + prilocaine 2.5%.
 Lidocaine – Base / HCl eg : Xylocaine, octocaine.
 Tetracaine HCl – eg : Supracaine.

37. ARMAMENTARIUM
SYRINGE

38. Types of Syringes Specific Uses Advantages Disadvantages
Non-Disposable
Syringes
Breech Loading,
Metallic,
Cartridge,
aspirating
Most Commonly used Visible Cartridge, Aspiration with one
hand, Autoclavable, Rust
resistant, long lasting
Heavier, Size - big,
possibility of infection
with improper care.
Breech Loading, Plastic,
Cartridge,
aspirating
Better appearance Better appearance, light weight,
visible cartridge, single hand
aspiration, lower cost, long
lasting.
Size-Big, Possibility of
infection,
deterioration with
repeated autoclaving.
Breech Loading,
Metallic,
Cartridge, self
aspirating
Self Aspirating,
Appropriate pressure
exerted on the
syringe for
aspiration.
Easier to aspirate with small hands,
piston is scored.
Doctors perception if
insecurity, weight,
Pressure Syringe for
periodontal
Ligament Injection
Isolated tooth Measured dose, overcome tissue
resistance, cartridges protected
Cost, control of speed of
injection
Jet Injector Needle phobic patients Does not require needle, least volume
(0.01 – 0.2ml), alternative to
Topical anesthetics
Inadequate extent of
anesthesia, cost, ?
periodontal damage,
Patients experience
the ‘Jolt’ of injection.

39. Disposable Syringes Used by us Economic, No maintenance,
Disposable, single use, changes of
cross infection is less, light weight.
Contamination of LA
vial, Aspiration is
difficult requires both the
hands.
Safety Syringes Prevents needle prick
injury
Light weight & better tactile
sensation.
Cost, acceptance of user
Computer Controlled Local
anesthetic delivery system
Comfort for patient and
clinician
Precise control of flow rate and
pressure produces comfortable
injection even in tissues with low
elasticity (Palate)
Increased tactile and ergonomics –
Light weight, self aspirating,,
rotational insertion technique,
minimizes needle deflection.
Requires additional
armamentarium.
Costly.

40. Jet injector
Computer controlled
injection

41. Cartridge Penetrating
end
Syringe
Adaptor
HubShank
Bevel
NEEDLES
Gauge – Diameter of the Lumen of the
needle.
Smaller the number, greater the size
Selection of gauge Needle
Depth of penetration
Risk of aspiration
Recommended for Dental use – 25, 27, 30

42. Cartridge
Drug Identifying
color coded band
Silicone Rubber
Plunger
Plunger
indented
from rim
of glass
Aluminum
Cap
Neck
Rubber
Diaphra
gm

43. Additional armamentarium includes
 Topical antiseptic
 Topical anesthetic
 Applicator sticks
 Cotton gauze
 Hemostat

44. BASIC INJECTION TECHNIQUES
• Use a Sterile Sharp Needle
• Check The flow of Solution
• Position the patient
• Dry the tissue/ wipe once.
• Apply topical anesthetic
• Topical antiseptic /optional
• Communicate with patient apply firm hand rest
• Inject few drops of soln, communicate with patient,
• Advance to the target slowly , aspirate , inject
• Withdraw the needle slowly
• Observe the patient & check for anesthetic symptoms

45. Different techniques of achieving LA
• Local infiltration
• Field block
• Nerve block
• Intraligamentry
• Intraseptal
• Intrapulpal
• Intraosseous injection
• Jet injector
• Computer controlled local anesthetic delivery system
• Electronic dental anesthesia
•Topical anesthesia

46. 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.

47. FIELD BLOCK
Local anesthetic solution is deposited near the
larger terminal nerve branches

48. NERVE BLOCK
Local anesthetic solution is deposited close to a main
nerve trunk usually located at a distance from the
site of operative intervention.

49. MAXILLARY INJECTION TECHNIQUE
SUPRAPERIOSTEAL INJECTION
• Anaesthetize buccal soft tissue & hard tissue
• Nerves anaesthetized – large terminal branches of dental plexus
• Indication :
1 or 2 teeth need to be anaesthetized / small area
• Contra-indication :
Infection
Dense bone covering

50. - Target area :
Behind apices of tooth
- Landmarks :
Muco-buccal fold
Crown & root length
Technique: 25 gauge needle is inserted beneath the mucous membrane in
to the connective tissue in the area to be anesthesized and the anesthetic
solution is infiltrated slowly through out the area.

51. POSTERIOR SUPERIOR ALVEOLAR NERVE BLOCK
• Area anaesthetized:
• Maxillary 3rd, 2nd & 1st molar (except mesio-buccal root of 1st
molar
• Bone & buccal periodontium over these
• Indication:
• Treatment of 2 or more molars required
• Supra-periosteal injection – ineffective
• Acute inflammation
• Contra-indication:
• Patients with bleeding disorders
• Disadvantage:
• More of soft tissue landmarks used
• 2nd injection for 1st molar

52.  Technique: Orient the bevel of the needle towards the bone, insert
the needle in to the height of muco buccal fold of second molar.
 Advance the needle slowly in an upward, inward (450 to occlusal
plane) and backward (450 to long axis of 2nd molar) direction in one
movement.
 Depth of penetration – approx 16 mm
 Aspirate if negative slowly deposit the LA

53. MIDDLE SUPERIOR ALVEOLAR NERVE BLOCK
 Area anesthesised
Maxillary first premolar and second premolars,mesiobuccal root of first
molar
Buccal periodontium and bone
 Indication
When infraorbital nerve block fails to provide anesthesia distal to maxillary
canine
Involving both maxillary premolars only
 Contraindications
infection or inflammation in the area of injection
 Advantages
minimizes no of injections

54. •Technique : Insert the needle to the height of mucobuccal fold
above the second premolar with the bevel directed towards
bone
•Aspiration negative, deposit LA slowly

55. •Areas anaesthetized
Pulp of maxillary Central Incisors to Canine,
•Indications
More than 2 anterior teeth
•Contraindications
Discreet treatment areas
Hemostasis of localized area – not adequately
achieved
ANTERIOR SUPERIOR ALVEOLAR NERVE BLOCK

56. Technique:
•Locate the infra orbital foramen
•Maintain finger on the foramen retract the lip
• Insert the needle into height of the muco buccal fold over the Ist premolar with
bevel facing the bone.
•Orient the syringe towards foramen and needle should be parallel to the long axis
of the tooth as it advance to avoid premature contact with bone.
•Advance the needle until it touches the upper rim of the foramen.
• Aspirate and slowly inject.

57. GREATER PALATINE NERVE BLOCK
 Areas anaesthetized - Palatal soft tissue – posterior aspect, Palatal hard tissue
 Indication
Surgical procedures posterior portion of hard palate
Palatal Anaesthesia in conjunction with posterior superior alveolar nerve
block.
 Technique: Locate the greater palatine foramen, distal to the maxillary second
molar, direct the syringe in the mouth from the opposite side with the needle
approaching the injection site at right angle. Solution is forced against the
mucous membrane and the needle advanced until palatal bone is gently
contacted. Depth of penetration is less than 10mm.
 Aspirate, if negative slowly deposit

59. NASOPALATINE NERVE BLOCK
• Areas anaesthetized
Anterior portion of hard palate from mesial of the Ist right premolar to
the mesial of Ist left premolar.
• Indications
Anterior palatal procedures supplementing infraorbital nerve blocks
Pain control during periodontal or oral surgical procedures.
Usually most discomforting block for patient – very painful

60. Single needle penetration
Apply pressure on the area of the incisive papillae and note the ischemic
soft tissue and place the needle there, slowly advance the needle to the
incisive foramen until gently contacts the bone (5mm Depth), aspirate if
negative slowly deposit the LA.
Multiple needle penetration :
1. Infiltration in to the labial frenum,
2. Penetrate to the labial aspect of the papillae between the central incisors
towards the incisive papillae.
3. Incase of failure of 2nd injection – Place the needle into the soft tissue
adjacent to the incisive papillae aiming towards the most distal portion
of papillae.

62. MAXILLARY NERVE BLOCK
• Areas anaesthetized
Maxillary teeth, Periodontium / soft tissue – 1 Quadrant
•Indications
Extensive oral / periodontal / endodontal procedures
Other regional nerve blocks not possible
•Contra-indications
Pediatric patients
Infection / inflammation
Hemorrhage – anticipated
Greater palatine canal approach not possible – bony obstruction.

63. Technique :
High tuberosity approach - The needle is inserted in the height of the
mucobuccal fold of the second molar and needle progresses as similar to
PSA block. The depth of penetration is 30mm. At this depth the needle
should lie in the pterygopalatine fossa in proximity to the maxillary
division of maxillary nerve, aspirate if negative slowly deposit the LA.
Greater palatine canal approach - Give the greater palatine nerve block and
slowly advance the needle into the greater palatine canal to a depth of 30
mm, aspirate if negative slowly deposit the LA

64. MANDIBULAR NERVE BLOCK
Inferior alveolar nerve block
•Areas anaesthetised
Mandibular teeth upto midline
Body of mandible
Inferior portion of ramus
Buccal periosteum & mucous membrane
Lingual soft tissue
Anterior 2/3rd of tongue
•Indications
Multiple mandibular teeth – procedures
Buccal / Lingual soft tissue anaesthesia

65. Technique
Height of Injection:
• Index finger or thumb to be placed in the cornoid notch, an imaginary line
extending from the finger tip in the cornoid notch to the deepest part of
pterygomandibular raphe.
•This line is parallel to the occlusal plane of Mandibular molar
• The needle is inserted parallel to the occlusal plane of the mandibular teeth from
the opposite side of the mouth, at a level bisecting the finger nail enters pterygo
mandibular space.
• Needle is penetrated until it gently contacts the ramus of the mandible.
• The needle is then withdrawn , and after aspirating slowly deposit the solution.
• For Lingual Nerve block – Needle is withdrawn half the inserted depth and lingual
nerve is blocked.

66. LINGUAL NERVE BLOCK

67. Closed mouth/ Vazirani Akinosi technique –
Mandibular nerve Block
 Indication:
Limited Mouth opening, Iniability to visualize the landmarks of IANB
 Technique:
Area of insertion – Soft tissue overlying medial border of the mandibular
ramus, directly adjacent to maxillary tuberosity at the height of muco gingival
junction adjacent to maxillary third molar.
.

68. The index/ thumb to be placed in the coronoid notch, ask patient to occlude
gently, syringe is held parallel with the maxillary occlusal plane, needle at the
level of muco gingival fold of third molar.
Direct the needle posteriorly and laterally 25 mm in to the tissue. On negative
aspiration deposit the LA

69. Gow gates technique– (Mandibular nerve block)
 Extra Oral Landmarks – Lower border of tragus (intertragic notch), Corner
of the mouth.
 Intra Oral Land marks – Height of injection below mesiolingual cusp of
maxillary 2nd molar.

70. • Direct the syringe towards the site of injection from the corner of the mouth from the
opposite side.
• Insert the needle gently into the tissue distal to the maxillary second molar parallel
to line of extra oral land mark.
• Slowly advance the needle until it touches the bone in neck of the condyle.
• On negative aspiration slowly deposit the LA.
• Ask the patient to keep the mouth open for 1-2 minutes for diffusion of LA.

71. Buccinator / long buccal nerve block
• Area anaesthetised
Buccal mucosa & mandibular molar – mucoperiosteum
• Land marks
External oblique ridge, retromolar triangle
• Technique – Direct the syringe towards the injection site with bevel facing
downwards towards the bone and syringe aligned parallel to the occlusal
plane. Advance needle until muco periostium is gently contacted. Depth of
pentration 2-4mm and on negative aspiration slowly deposit LA.

72. Mental nerve block
 Areas anaesthetized
Lower lip, mucous membrane – anterior to mental foramen.
 Land mark. Mandibular bicuspids
 Technique – Locate mental foramen, apex of second premolar feels as
bony irregularity in the depth muco buccal fold.
Needle is penetrated in the muco buccal fold of the canine or first premolar
region directing the syringe towards mental foramen. Advance the needle
untill mental foamen is reached 5-6 mm depth, on negative aspration
deposit the LA.

73. Periodontal Ligament injection
•Areas Anesthetized
Bone, soft tissue, apical and pulpal tissues in area of
injection.
•Indications
Treatment of isolated teeth in 2 mandibular quadrant
Patients for whom residual soft tissue anesthesia is
undesirable,
When regional anesthesia is contraindicated
•Contraindication:
Possibility of enamel hypoplasia if used in primary with
underlying permanent bud

74. • Advantages:
Prevents anesthesia of lip, tongue and other soft tissues, thus facilitating
treatment of multiquadrant in single visit.
• Disadvantage:
Leakage of LA – Unpleasant taste,
Proper needle placement difficult
tissues damage due to excessive pressure

75. Technique:
Direct the syringe along the long axis of the tooth anesthetized bevel
facing the root of the tooth. Syringe should be directed either lingual/
buccal surface of tooth, advance the needle untill resistance is felt.
Deposit the LA.

76. Intraseptal injection
 Indications
When both haemostasis & pain control are desired for soft
tissue & osseous periodontal treatment
 Contraindications
Infection or severe inflammation at the site of injection

77. Intra Osseous Technique
 Special syringe – Stab Dent System/ X-Tip
 Requires initial perforation of bony surface made and then LA is injected.

78. 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.

79. LOCAL COMPLICATIONS
• Needle breakage
• Pain on injection
• Burning on injection
• Persistent anaesthesia or paresthesia
• Trismus
• Hematoma
• Sloughing of the tissue / soft tissue injury
• Facial nerve paralysis

80. SYSTEMIC COMPLICATIONS
• Toxicity
• Idiosyncracy
• Allergy
• Anaphylaxis
• Syncope

81. NEEDLE BREAKAGE
•Cause
Unexpected movement – patient (if patient movement is opposite to path of needle
insertion)
Multiple used needle
Defective manufacture of needles/barbed needles
smaller gauge – more likely to break
• Prevention
Correct gauge – 25 gauge
Long needles – prevent penetration till hub
Not to redirect when in tissue
• Management
Patient – not to move – hand in the mouth – mouth open
Fragment visible – remove it
Fragment not visible – inform patient – not necessary for intervention immediately
– Radiograph suggested

82. PAIN ON INJECTION
Causes –
Careless injection
on technique
Multiple used needle
Rapid deposition
Prevention –
Proper technique – sharp needles
Enter topical anesthetics
Inject slowly – solution sterilized
Check temperature of solution
BURNING ON INJECTION
Causes
Due to pH of solution
Rapid injection
Contamination
Warm solution

83. PERSISTENT ANESTHESIA/ PARESTHESIA
Causes
Direct trauma to nerve – bevel of needle
LA solution containing neurotoxic substance – alcohol
Injection of wrong solution
Hemorrhage / infection – near to nerve
Prevention
Proper care & handling of dental cartridge
Adherence to injection protocol
Management
Usually resolve in 8 weeks
Periodic recall & check up of patients
Persistence – consult neurosurgeon
Recall patient every 2 months for check up-

84. TRISMUS
“difficulty in opening the jaws due to muscle spasm”
Causes
Trauma – muscle / blood vessel
Irritating solution
hemorrhage
Infection
Multiple needle punctures
LA have been known to have slight myotoxicity
Excessive volume – distension of tissues

85. Prevention
Use of sharp, sterile, disposable needle
Aseptic technique
Practice atraumatic methods
Avoid repeated injections
Use minimum volume
Control infection
Management
Heat therapy - Warm saline rinses, moist hot packs
Analgesics - Aspirin, Codeine (30-60mg), muscle relaxants
Initial physiotherapy - Thrice a day
Antibiotic regime - Possibility of infection

86. HEMATOMA
effusion of blood into extra-vascular space
Causes
Arterial & venous puncture – common in PSA &
Inf. Alv. nerve blocks
Patients with bleeding disorders
Problem
Bruise – may / may not be visible extra-orally
Complications – pain & trismus
Swelling & discoloration
Prevention
Knowledge of normal anatomy – proper technique
Shorter needle
Discard defective needles

87. Management
Direct pressure applied immediately at the site of bleeding.
Analgesic – aspirin
Do not apply heat to the area for 4 – 6 hours as heat causes vasodilatation which
may increase the size of the hematoma
Ice may be applied immediately to that area
With or without treatment, hematoma will be present for 7 to 14 days

88. EDEMA
Causes
Infection, hemorrhage
Trauma during injection
Allergy (Angioedema)
Injection of irritating solution
Problems
Pain & dysfunction
Airway obstruction
Prevention
Proper care & handling of armamentarium
Atraumatic injection technique
Complete medical evaluation prior to injection
Management
Trauma – resolve in few days without therapy
Hemorrhage – resolve slowly 7-14 days
Allergy – life threatening
Total airway obstruction – Tracheostomy

89. FACIAL NERVE PARALYSIS
Cause
LA solution into parotid gland – usually while giving Inferior Alveolar
Nerve Block, Akinosi technique
Problem
Ipsilateral loss of motor control – Buccinator muscle
Inability to raise the corner of Mouth, close Eye lid
Prevention
Needle tip to contact bone, redirection of needle to be done only after
complete withdrawal
Management
Reassure the patient
Resolves after action of LA is over
Eye patches to the affected – eye drops
Contact lenses if any – removed

90. OVER DOSAGE/TOXICITY
Causes :
Total dosage of LA administered is too large.
Absorption of LA from the site of injection is rapid.
Intravascular administration.
Unusually slow biotransformation.
Slow elimination though the kidney.

91. CNS
Agitation, talkativeness, irritability.
Tonic clonic seizures.
CNS depression, Respiratory arrest.
CVS
Alterations in ECG.
Myocardial depression.
Decreased cardiac output.
Peripheral vasodialation.
Severe bradycardia → cardiac arrest.

92. Management
- Stop all procedures.
- Reassure the patient.
- Monitor vital signs.
- Maintenance of airway.
- Anticonvulsants.
- Oxygen administration.
- Medical assistance

93. SYNCOPE
transient loss of consciousness that is caused due to cerebral ischemia (neurogenic
shock)”
Clinically:
light headedness
dizziness
tachycardia &
palpitation – may further lead to Unconsciousness
Treatment :
discontinue procedure
supine position
deep breathing
O2 administration if required

94. ALLERGY/HYPERSENSITIVITY
Hypersensitive state acquired through exposure to a particular allergen reexposure to
which produces a heightened capacity to react
1 % of all reaction in LA is allergy
Predisposing factors
Hypersensitivity to ester more common-procaine
Most of patients allergic to methyl paraben
Recently allergy to sodium meta bi sulfide is also increasing
Precautions
H/o of allergy to be recorded
H/o any asthmatic attack to be noted.
Always better to test the patient for allergy before treatment

95. Laryngeal edema:
 oxygen, broncho-dilator, iv anti histamines.
 achieve patent air way
 if necessary give artificial ventilation.
Patient with confirmed allergy status:
• if patient allergic to any one type of anesthetic ester / amide use the other.
• Use histamine blocker like diphenhydramine as anesthetic.
• General anesthesia

96. Management
skin reactions:
• Delayed – non life threatening - oral histamine blockers- 50 mg diphenhidramine
• Immediate reaction—with conjunctivitis rhinitis- vigorous management.
1 mg epinephrine. IM
50 mg diphenhydramine IM
medical help
Observe patient for minimum of 60 min
Oral histamine blockers for 5 days.
• Respiratory reaction :
patient in comfortable position.
administer - oxygen
Admn epinephrine- bronchodilator
Observe for 60 min , advice anti histamines to prevent relapse.

97. local anesthetic considerations in periodontics
• Special requirements for local anesthetic in periodontics revolve around the
use of vasoconstrictor to provide hemostasis
• The use of local anesthetic without vasoconstrictor actually proves to be
counterproductive because the vasodilatory action of local anesthetic increases
bleeding at the site of injection. Vasoconstrictor is therefore added to local
anesthetic to counteract this unwanted action
• Local anesthetic solutions include a vasoconstrictor in concentration not
greater than 1:100,000 epinephrine

98. • Pain control for periodontal procedures should be achieved through
nerve block techniques such as PSA, ASA, IANB
• Intraseptal injection has proven to be quite effective for periodontal flap
surgical procedures. Also post surgical discomfort was minimized
• Long acting such as bupivacaine and etidocaine are frequently used in
periodontal treatment to aid in post surgical pain control

99. Future trends in pain control
Newer drugs:
•Centbucridine and ropivacaine
These drugs are more potent than lidocaine and have much superior therapeutic
index.
•Eutectic mixture of local anesthetics (EMLA) – they are the latest topical
anesthetics which can exert its anesthetic action even on intact skin.
Usage of Hyaluronidase
Advocated as an additive to local anesthetics
It permits injected solutions to spread and penetrate tissues
Due to the lytic activity on connective tissue

100. Newer Techniques – Electronic dental anesthesia
The use of electricity to control pain is not a recently evolved idea. History tells
us that electricity was tried as pain control, back in 46 AD. It is used to control
both acute and chronic pain. In chronic pain, low frequency of 2 hertz is used
whereas in acute pain higher frequency of about 120 Hz is used.
Indications:
Temporomandibular joint pain
Administration of local anesthesia
Non surgical periodontal procedure
Restorative dentistry
Fixed prosthodontic procedures
Endodontic procedures

101. CONCLUSION
Pain management is an ethical obligation that improves
satisfaction and recovery to the patient.
Proper care and precautions must be taken before administering
LA
Hence this is the primary technique for pain control it is
obvious that dentists are unwilling to abandon
local anesthesia

102. References
- Local Anesthesia, Fifth Edition, Stanley F Malamed, DDS
- Local Anesthesia and Pain Control in Dental Practice –Seventh
Edition, Monheims
- Dental Anesthesia and Analgesics, G.D.Allen
- Local anesthesia of the Oral Cavity,J.Theodore Jastak,John
A.Yagiela, David Donaldson
- Clinical Peridontology and Implant Dentistry, Fifth Edition, Niklaus
P.Lang and Jan Lindhe.

103. THANK YOU