Recent advances in Local anesthesia

bpkihs dharan

1. RECENT ADVANCES IN
LOCAL ANESTHESIA
RESOURCE FACULTIES
DR. MEHUL JAISANI
DR.ASHOK DANGOL
DR. PRADIP ACHARYA
DEPARTMENT OF ORAL MAXLLOFACIAL SURGEY
,CODS,BPKIHS
PRESENTER
Nitesh chaurasia 489
Papular chaudhary491

2. CONTENTS
Introduction
Newer LA Drugs
LA Delivery Systems
CCLAD system
Jet injectors
Safety dental syringe
Devices for intra-osseous anesthesia
Vibrotactile devices
Intra nasal anesthetic

3. INTRODUCTION
The most important skill required of all dental
practitioners is the ability to provide safe and
effective local anesthesia
 Most of the researches are focused on improvement
in the area of anesthetic agents, delivery devices
and technique involved.
Newer technologies have been developed that can
assist the dentist in providing enhanced pain relief
with reduced injection pain and fewer adverse effects

4. Newer drugs
Lignocaine Hydrochloride is considered the “Gold
Standard among LA.
‟
Two relatively new drugs that have proved to be
equally or more efficient to Lignocaine are
1. Articaine
2. Centbucridine

5. Articaine
 It belongs to the Amide group of local anesthetics.
It consists of a thiophene ring instead of a benzene
ring and an ester group that is metabolized by
esterases in the tissues.
Elimination of Articaine is exponential with a half-life
of about 27 minutes.
 Metabolism is mainly in the liver and plasma
 5-10% secreted unchanged and 90% is
metabolized.

6. Articaine vs. Lignocaine:
1. Articaine has a faster onset of action
2. Articaine has a longer duration of action
3. Articaine has a higher success rate
4. Articaine has a greater potency (1.5 times
more potent)
5. Systemic intoxication of Articaine is lower
6. Articaine is a very safe drug

7. Continue..
The thiophene ring bestows enhanced
performance by increasing the lipid solubility
and protein binding capacity of the drug
Lipid solubility and protein binding properties
are intrinsic qualities of a local anesthetic drug
molecule
enhanced diffusion into soft and hard tissues
than other local anesthetics

8. Continue..
Articaine has a smaller pK value
 1.7 times greater volume needed for lignocaine 2%
to that of 4% Articaine for achieving the same
anesthesia
One study revealed that 4% Articaine with
1:1,00,000 epinephrine was the most effective
solution
Articaine buccal infiltration enhances the
effectiveness of lidocaine IANB

9. Other properties of Articaine
Pka- 7.8
PH of vasoconstrictor- containing solution is 3.5 -4
Onset of action: 1-2 min for infiltration and 2-2.5 for
mandibular block(for 1:100000)
Effective dental concentration: 4%with 1;100000 or
1:200000
MRD:7.2mg/kg with no absolute maximum
Duration of action:60-75 min of pulpal anesthesia for
1:100000

10. Documented Adverse effect: methemoglobinemia,
paresthesia
Ocular complications have been reported for infra-
orbital nerve block. This may be due to the increased
diffusion of drug through the tissues including bone
Not recommended in children below 4 year and
lactating mother
Pregnancy falls under class C

11. Centbucridine
synthesized at the Centre for Drug Research of India
at Lucknow, India in the year 1983
 A quinolone derivative with local anesthetic action .
 It has intrinsic vasoconstricting and anti-histaminic
properties.
Concentration of 0.5% can be used effectively for
infiltration, nerve blocks and spinal anesthesia.

12. Randomized study result
compared the efficacy and tolerability of 0.5%
Centbucridine with 2% lignocaine for dental
extractions
 the results revealed that the dose of analgesia
obtained with Centbucridine compared well with
that of lignocaine
it was well tolerated without any serious side-
effects or significant changes in the cardio-
vascular parameters

13. Lignocaine vs centbucridine
Anesthetic potency 4-5 times greater than that of
2% lignocaine.
Onset of action is quicker and duration is longer
It doesnot require simultaneous administration of
adrenaline
It doesnot effect the CVS parameter due to its
moderate antihistaminic activity and is not likely to
show skin sensitivity.
Can be used in patient hypersensitive to
lignocaine.

14. Centbucridine has been tested successfully as a
topical anesthetic in ophthalmic surgeries.
 Its topical anesthetic action is concentration
dependent.
Its use in dentistry is still a matter of study

15. Phentolamine(OraVerse)
an indication for the reversal of soft tissue anesthesia
(lip & tongue numbness).
Phentolamine Mesylate is a non-selective alpha
adrenergic blocking agent and reverses the effects of
epinephrine and nor-epinephrine on tissues

Medical uses:diagnosis of pheochromocytoma, tt of
HTN in pheochromocytoma and prevention of tissue
necrosis after norepinephrine extravasation.

16.  The ultimate effect of alpha receptor blockade
is vaso-dilatation.
Peak concentration is achieved after 20 minutes
and the elimination half-life is 2-3 hours.
Availabe injectable dose 0.4mg/1.7ml(max.
0.8mg)
Dose based on amount of local anesthetic
administred
½ cartridge of LA :1/2 cartridge of phentolamine
(0.2mg)

17. Candidates for phentolamine reversal are:
1.Conservative dentistry
2.Nonsurgical periodontics
3.Pediatric dentistry
4.Medically compromised patient
5.Special need patient and post mandibular
implant

18. Adverse reactions such as diarrhea, facial swelling,
hypertension, jaw pain, oral pain, injection site
reactions, tenderness and vomiting have been
reported.
 Majority of the adverse reactions are resolved
within 48 hours.
 Administration with caution in patients with
cardiovascular disease and stroke.
Is not recommended in children younger than 6
years of age and weighing less than 15 kg

19. Buffered local anesthetics
Standard Local anesthetic solution are
buffered few mins before injection with
sodium bicarbonate
PH of buffered dental cartridge of LA ranges
between 7.35 -7.5( i.e.closer to physiologic
range)
Well known and accepted in medicine but
prefilled LA cartridge in dentistry has limited
its use

20. Advantages
Elliminates the sting on injection( greater
patient comfort during inection)
More rapid onset of action(2 min)
Reduces tissue and post injection soreness
Introduces the independent anesthetic action
of CO2
Introduces catalytic effect of CO2

21. Action of CO2
Direct depressant effect on axon
Concentrating the local anesthetic inside the
nerve trunk though ion trapping
Changing the charge of local anesthetic inside
the nerve axon

22. EMLA – Eutectic Mixture of
Local Anesthetics
Used as topical anesthetic able to provide
surface anesthesia for intact skin
Composed of lidocaine 2.5% and prilocaine
2.5%
Supplied as a 5g or 30g tube or as an EMLA
anesthetic disc.
EMLA anesthetic disc is packaged in
protective laminate foil surrounded by
adhesive tape.

23. Indication
As topical anesthetic in pediatric patient and
needle phobic patient
Venipuncture
Circumcision and gynecologic procedure
During leg ulcer debridement
Note: should be applied 1 hr before the
procedure.

24. Contraindicated
Patient with congenital or idiopathic
methemoglobinemia
Infants younger than 12 month who are
receiving treatment with methemoglobine
inducing agent
Known sensitivity to amide type LA

25. Lidocaine and prilocaine
periodontal gel
(Oraqix)

26. Lidocaine and prilocaine
periodontal gel 2.5%/2.5%
(Oraqix)
Eutectic mixture of local anesthetics
Solution at room temperature; gel at body
temperature
First topical anesthetic specifically designed
for scaling and root planing

27. Oraqix delivery syringe

28. Oraqix cartridge contents
Lidocaine/prilocaine 2.5%/2.5%
Poloxamers 188 and 407
HCl for pH adjustment
Purified water
pH 7.5-8.0

29. Newer Drug delivery
system for dental LA

30. Electronic Dental Anesthesia
 Principle of Transcutaneous Electrical Nerve
Stimulation (TENS) which has been used for the
relief of pain.
Some limitations are increased salivary flow and
inability to use metal instruments freely.
It is powered by a battery ,two small sponges are
placed in the patients mouth or on the face, which
are attached to the control box that the patient uses
to select the depth of anesthesia

31. Indication
Patient having needle phobia
Ineffective LA
Instances where LA cannot be administered
 TMJ(chronic pain)
Nonsurgical periodontal pain
Restorative dentistry
Fixed prosthodontic procedure
Reversal of soft tissue anesthesia

32. Advantages
No need of needle
No need for injections of drugs
Patient is in control of the anesthesia
No residual anesthetic effect at the end of
procedure
Residual analgesic effect remains for
several hours

33. Disadvantages
Cost of the unit
Training
‘Learning curve‘ initial success may be
low but increases with experience
Intraoral electrode:weak link in the entire
system

34. It is contraindicated in several conditions
such as
heart disease,
seizures,
neurological disorders,
brain tumors,
patients wearing pacemakers and cochlear
implants

36. Dentipatch
a patch that contains 10-20% lidocaine is
placed on the dried mucosa for 15
minutes.
Hersh et al (1996) studied the efficacy of
this patch and recommended it for use in
achieving topical anesthesia for both
maxilla and mandible.

38. Jet Injection
Jet-injection technology is based on the
principle of using a mechanical energy source
to create a release of pressure sufficient to
push a dose of liquid medication through a very
small orifice.
creating a thin column of fluid with enough force
that it can penetrate soft tissue into the
subcutaneous tissue without a needle

40. advantages over traditional needle
injectors by
being fast and easy to use,
with little or no pain,
less tissue damage, and
faster drug absorption at the injection site
This technique is particularly effective for
palatal injections
Marketed as Syrijet and MED-JET H III

41. Iontophoresis
Iontophoresis is non-invasive transdermal
drug delivery
This technique is a suitable alternative for
application of drug in achieving surface
anesthesia.
It is a painless modality of administrating
anesthesia.

42. a fast and effective way to apply a local
anesthetic without needles or pain. The
method is faster and penetrates deeper than
topical anesthetic creams and is an ideal
alternative for numbing the skin before
injections and biopsies.
After just 10 minutes, the skin is as numb as
after 60 minutes of traditional treatment with
creams.

43. We recommend a Xylocaine topical
anesthetic solution, 40 mg/ml.
 Xylocaine has a positive charge, so
connect the anode (red clamp) to the drug
delivery electrode

45. CCLAD Systems (Computer Controlled
Local Anesthesia Delivery System)
Introduced the first CCLAD system in 1997 and
was termed the “WAND” and the subsequent
versions were renamed as “WAND PLUS”
and“COMPUDENT”.
In 2001, DENTSPLY International introduced the
“Comfort Control Syringe – CCS” and similar
devices originating outside USA were; “Quick
Sleeper, Sleeper
One from France, “Anaeject” and “Orastar” from
Japan.

46. Wand” has 3 components: Base unit, Foot pedal
and Disposable Handpiece assembly
Base unit consists of a microprocessor and
connects to the foot pedal and Handpiece
assembly that accepts the LA cartridge.
 LA solution from the cartridge passes through
the microbore tubing in the Handpiece assembly
and needle into the target tissue

47. Rate of Injection: foot pedal controls the rate of
injection and if aspiration feature is enabled, it
prevents inadvertent intravascular injections.
1. Slow: 0.005ml/s – needle insertion, PDL
injection, Palatal administration
2. Fast: 0.03ml/s – buccal infiltrations, nerve
block
3. Turbo: 0.06ml/s

48. “Single Tooth Anesthesia System – STA System” was
introduced by Milestone Scientific in 2007.
 Its advantages include „Dynamic Pressure Sensing –
DPS
‟
 which provides continuous feedback to the user about
the pressure at the needle tip to identify the ideal needle
placement for PDL injections.
Rate of Injection: 3 modes to control the rate of injection
1. STA mode: Single, slow rate of injection
2. Normal mode: emulates the Compudent device
3. Turbo mode: faster rate of injection – 0.06ml/s

50. Comfort Control Syringes
 consists of two components; base unit and syringe.
The most important functions of the unit (injection and
aspiration) can be controlled directly from the syringe.
Rate of injection: Five different basic injection rate
settings for specific applications: block, infiltration,PDL,
IO and Palatal regions.
The unit uses two stage delivery rates for every
injection.
It initially expresses the LA solution at an extremely low
rate and after 10 seconds the rate slowly increases to
the pre-programed value for the selected injection
technique.

52. Advantages of CCLADs
1) Ability to administer small quantities of LA solution
continuously during needle insertion, which anesthetizes
the tissue immediately ahead of the advancing needle.
2) Steady infusion of the anesthetic solution at the target
site reduces the discomfort associated with less controlled
injections.
3) More accurate needle insertion
4) Less pain on injection
5) Less fear of injection
6) More controlled insertion of the needle

53. 7) Ability to rotate the Handpiece back and forth during
needle insertion to avoid needle deflections & reduced
force for insertion leading to more comfort for patients.
8) Ability to perform newer techniques such as
a. AMSA – anterior middle superior alveolar block
b. PDL – periodontal ligament infiltration
c. P-ASA – palatal approach to anterior superior
alveolar block.

54. Because of these attributes the CCLAD
devices are better tolerated by patients
and produce less disruptive behavior can
be used successfully for
 restorations,
pulpal therapies &
extractions in pediatric dentistry

55. Intra-Osseous Anesthesia
The use of motor driven perforator to penetrate the
buccal gingiva and bone can be considered as the first
modern technique of IO anesthesia.
The devices used for this technique, inject the solution
into the cancellous bone adjacent to the root apex.
Commonly used devices are:
i. Stabident
ii. X – Tip
iii. Intraflow

56. (i)Stabident:
It includes a solid 27 gauge perforator needle with a
beveled tip and a plastic base which fits a latch type slow
speed contra-angle handpiece.
This perforator creates a small tunnel through attached
gingiva,periosteum and alveolar bone.
The insertion point of the perforator is in the attached
gingiva, 2mm below the facial gingival margin and
midway between the tooth of intent and immediately
adjacent (distal) tooth.

57. The angle of perforation is usually
directed apically in the mandibular incisor
region whereas a more perpendicular
angle is advantageous in the molar region
to avoid bending the perforator against
the dense cortical bone.
 Later a 27 gauge ultra-short needle is
used to deposit the local anesthetic
solution

59. (ii)X-tip
X – Tip: this system consists of three parts; the
drill,perforator, 25 gauge guide sleeve
The advantage of this system over Stabident
 the ease with which the perforation could be located for
inserting the needle.
The drill leads the guide sleeve through the cortical
plate into the cancellous bone.
The drill portion is removed, leaving the guide sleeve in
place, which directs the needle into the cancellous bone
to deposit the LA solution. Later the guide sleeve is
removed with a hemostat

60. (iii)Intraflow
the Intraflow HTP Anesthesia Delivery System is an “all
in one” system that allows the operator to perforate the
bone and deposit the anesthetic solution in a single
step.
The device is a dental handpiece equipped with an
injection system built into its body. A 24 gauge hollow
perforator is used to penetrate the bone and infuse the
LA solution.

63. The anesthetic solution from the cartridge
is routed to the perforator by a disposable
transfuser that also serves to cover the
switch used to select between the
perforator rotation and anesthetic infusion
modes.
Penetration with this low speed high
torque device is by a single, steady
insertion using direct pressure

64. Vibrotactile devices
aimed at easing the fear of the needle take
advantage of the gate control theory of pain
management, which suggests that pain can
be reduced by simultaneous activation of
nerve fibers through the use of vibration
Devices are :vibrajet,dentvibe and accupal

65. VibraJet
It is a small battery-operated attachment that
snaps on to the standard dental syringe. It
delivers a high-frequency vibration to the
needle that is strong enough for the patient to
feel.

66. DentalVibe
It is a cordless, rechargeable, hand held
device that delivers soothing, pulsed,
percussive micro-oscillations to the site where
an injection is being administered.
 Its U-shaped vibrating tip attached to a
microprocessor-controlled Vibra-Pulse motor
gently stimulates the sensory receptors at the
injection site, effectively closing the neural
pain gate, blocking the painful sensation of
injections.

67. It also lights the injection area and has an
attachment to retract the lip or cheek

68. Accupal
A cordless device that uses both vibration and
pressure to precondition the oral mucosa.
 Accupal provides pressure and vibrates the injection
site 360° proximal to the needle penetration, which
shuts the “pain gate,” according to the manufacturer.

applying moderate pressure, the unit light up the
area and begins to vibrate. The needle is placed
through a hole in the head of the disposable tip,
which is attached to the motor.

69. Intranasal LA
The absorption of drugs through the nasal
mucosa to achieve a systemic effect has long
and varied history
The nares are extremely vascular so most
drugs instilled into them will be absorbed
rapidly and distributed systematically
Snorting line of cocaine is an example of illicit
use of this route of drug administrations

71. Critical care medicine has used intranasal
drug administration of the central nervous
system depressant drug midazolam in the
management of status epilepticus in
young children
Midazolam(0.2mg/kg)and diazepam(0.3
mg /kg)

72. Uses
Ear, nose and throat surgical procedures
Tetracaine,an ester type local anesthetic
,is commonly used to provide a numbing
effect before surgical manipulations in the
nose
For dental ,vasoconstritor oxymetazoline
is added to the teracaine to enhance
effecticveness.

73. references
Hand book of local anesthesia by Stanley
F. Malamed
IOSR Journal of Dental and Medical
Sciences (JDMS)
www.iosrjournals.org
www.ncbi.nlm.nih.gov/pmc/articles/PMC3
800379/