simple presentation about Local Anesthetics in Dentistry

1. Local Anesthetics in DentistryLocal Anesthetics in Dentistry
By:By:
Mustafa SalarMustafa Salar

2. Common uses of localCommon uses of local
anestheticsanesthetics
 ExcisionExcision
 DermatologyDermatology
 DentistryDentistry
 Spinal anesthesiaSpinal anesthesia

3. What are local anesthetics?What are local anesthetics?
 Local anestheticLocal anesthetic
produce loss ofproduce loss of
sensation to pain in asensation to pain in a
specific area of the bodyspecific area of the body
without the loss ofwithout the loss of
consciousnessconsciousness

4. Mechanism of actionMechanism of action
 Local ans. works by temporaryLocal ans. works by temporary
blocking the pathway of pain signalsblocking the pathway of pain signals
along nerves.along nerves.
 This is achieved by anestheticsThis is achieved by anesthetics
reversibly binding to and inactivatingreversibly binding to and inactivating
sodium channels.sodium channels.
 As a result, the nerve losesAs a result, the nerve loses
depolarization and the capacity todepolarization and the capacity to
create the impulse, the patient losescreate the impulse, the patient loses
sensation in the area supplied by thesensation in the area supplied by the

5. Local anesthetics are classified accordingLocal anesthetics are classified according
to Chemical Structure!to Chemical Structure!
 Ester-linkedEster-linked
•• Short actingShort acting
•• Metabolized in the plasma and tissue fluidsMetabolized in the plasma and tissue fluids
•• Excreted in urineExcreted in urine
 Amide-linkedAmide-linked
•• Longer actingLonger acting
•• Metabolized by liver enzymesMetabolized by liver enzymes
•• Excreted in urineExcreted in urine

6. Structures of Amides and EstersStructures of Amides and Esters
 The amine end is hydrophilic (soluble in water)
 The aromatic end is lipophilic (soluble in lipids).

7. VasoconstrictorVasoconstrictor
 Vasoconstrictor help in providing bloodVasoconstrictor help in providing blood
less fieldless field
 It help in prolongation of durationIt help in prolongation of duration
 increase penetration of LA to coarse fiberincrease penetration of LA to coarse fiber

8. LidocaineLidocaine
 In 1940, the first modern localIn 1940, the first modern local
anesthetic agent was lidocaine,anesthetic agent was lidocaine,
trade name Xylocaine®trade name Xylocaine®
 Lidocaine relieves pain duringLidocaine relieves pain during
the dental surgeriesthe dental surgeries
 Belongs to the amide class,Belongs to the amide class,
cause little allergenic reaction;cause little allergenic reaction;
it’s hypoallergenicit’s hypoallergenic
 Sets on quickly and produces aSets on quickly and produces a
desired anesthesia effect fordesired anesthesia effect for
several hoursseveral hours

9. Side effectsSide effects
Levels of local anesthetic concentration administered to
patients are varied according to age, weight, and health.
Maximum dose for an individual is usually between 70mg
to 500mg
The amount of dose also varied based on the type of
solution used and the presence of vasoconstrictor

10. Some common toxic effects:
 light headedness , shivering , seizures
 hypotension , numbness

11. Three special drugs used in dental anesthesiaThree special drugs used in dental anesthesia
 Bupivicaine
--Produce very long acting anesthetic effect to delay the post operative
pain from the surgery for as long as possible
-- solution with vasoconstrictor
--time is longer than other drugs b/c most of the radicals (about 80%)
bind to sodium channel proteins effectively
--most toxic local anesthetic drug
 Prilocaine
-- similar to lidocaine
--Almost same duration as lidocaine
--Less toxic in higher doses than lidocaine b/c small vasodilatory activity
 Articaine
--newest local anesthetic drug
--similar action and toxicity as lidocaine
--Used with vasoconstrictor.
--The drug is widely used in most nations today

12. contraindicationcontraindication
▪ Patients with more significant cardiovascular disease
▪ Patient with certain non-cardiovascular disease
(eg; thyroid dysfunction and sulfite sensitivity)
▪ Lignocaine is contraindicated in patients with
hypertension