LOCAL ANESTHESIA for the DENTAL HYGIENIST
Second Edition Demetra Daskalos Logothetis, RDH, MS
Professor Emeritus and Graduate Program Director
Department of Dental Medicine University of New Mexico,
Albuquerque, New Mexico Educational Consultant, Albuquer
Acetylsalicylic// Acid// (Aspirin)/ / -// ANSWER:// ASA//
antipyretic/ / -// ANSWER:// reduces// fever// (Tylenol,// aspirin)
Epinephrine// is// naturally// secreted// by// the// adrenal// glands// and// the// sympathetic// nerve// fibers.//
The// hormone// can// be// obtained// via// extraction// from// the// adrenal// glands// of// cattle// and//
sheep,// or// it// can// be// made// in// a// laboratory.// Synthetic// production// of// epinephrine// entails// the//
reaction// of// catechol// and// chloroacetyl// chloride./ / -// ANSWER:
antipyretic/ / -// ANSWER:// reduces// fever// (Tylenol,// aspirin)
In// 1842,// it// was// reported// that// William// Clarke// administered// ether,// via// a// towel,// to// a// woman//
as// one// ofher// teeth// was// extracted// by// a// dentist./ / -// ANSWER:
Tagamet// (cimetidine)// decreases// hepatic// blood// flow// and// inhibits// hepatic// metabolism// of//
amides,// particularly// lidocaine,// by// competing// for// binding// to// hepatic// oxidative// enzymes,//
and// therefore// increases// half// life// of// the// amide// anesthetic,// augmenting// the// risk// for// toxic//
overdose./ / -// ANSWER:
Morphine/ / -// ANSWER:// narcotic// drug// derived// from// opium,// used// to// treat// severe// pain
Horace// Wells,// a// dentist,// first// tried// nitrous// oxide// for// dental// pain// control// after// attending//
several// "laughing// gas"// parties./ / -// ANSWER:
He// practiced// on// himself// by// using// nitrous// oxide,// which// he// considered// safer// than// ether,//
and// had// a// fellow// dentist// extract// his// tooth.He// felt// nothing// during// the// extraction// and//
discovered// nitrous// oxide// to// be// an// effective// anesthetic./ / -// ANSWER:
Page// 1// of// 62
,Halothane,// a// safe// and// stable// chemical// for// inhalation// anesthesia,// was// introduced// in// 1956./ /
-// ANSWER:
Halothane// (Fluothane)/ / -// ANSWER:// halogenated// hydrocarbon// volatile// liquid//
anesthetic// with// good// maintenance
The// first// local// anesthetic,// cocaine,// was// isolated// from// coca// leaves// by// Albert// Niemann// and//
Francesco// Di// Stefano// in// Germany// in// the// 1860s./ / -// ANSWER:
Cocaine// was// first// used// as// a// local// anesthetic// in// 1884// by// Karl// Koller,// who// demonstrated//
the// use// during// painless// ophthalmological// surgery./ / -// ANSWER:
In// 1905,// the// ester// procaine// (Novocaine)// was// created// in// Germany// and,// when// mixed// with// a//
proportion// of// epinephrine,// was// found// to// be// effective// and// safe/ / -// ANSWER:
Procaine// took// a// long// time// to// produce// the// desired// anesthetic// result,// wore// off// quickly,// and//
was// not// as// potent// as// cocaine.// Additionally,// many// patients// were// allergic// to// procaine//
because// procaine// is// an// ester// that// has// a// high// potential// for// allergic// reactions./ / -//
ANSWER:
In// the// 1940s,// a// new// group// of// local// anesthetic// compounds,// the// amides,were// introduced.//
The// initial// amide// local// anesthetic,// lidocaine,// was// synthesized// by// the// Swedish// chemist//
Nils// Lofgren// in// 1943./ / -// ANSWER:// Lidocaine// revolutionized// pain// control// in//
dentistry// worldwide,// because// it// was// both// more// potent// and// less// allergenic// than// procaine.//
In// the// succeeding// years,// other// amide// local// anesthetics// (prilocaine// in// 1959,// bupivacaine//
and// mepivacaine// in// 1957)// were// introduced.
These// new// amide// local// anesthetics// provided// the// dental// practitioner// with// an// array// of//
local// anesthetics// for// pulpal// anesthesia// that// could// last// from// 20// minutes// (mepivacaine//
plain)// to// 3// hours// (bupivacaine// with// epinephrine)/ / -// ANSWER:
In// 1969,// Rusching// and// colleagues// prepared// a// new// drug,// carticaine,// which// differed// from//
the// previous// amide// local// anesthetics/ / -// ANSWER:// Renamed// articaine// in// 1984,// the//
drug// was// derived// from// thiophene// and// thus// contained// a// thiophene// ring// in// its// molecule//
instead// of// the// usual// benzene// ring.// Articaine// became// available// in// 2000// for// marketing// in//
the// United// States// in// a// 4%// 1:100,000// epinephrine// formulation.
Page// 2// of// 62
,Today,// lidocaine// remains// the// most// popular// anesthetic// used// in// dentistry// in// the// United//
States;// however,articaine// is// increasing// in// its// popularity// and// is// a// close// second// to//
lidocaine.Many// patients// do// not// understand// the// distinction// among// the// agents// and// still//
ask// for// Novocaine,// which// is// no// longer// available// in// dentistry./ / -// ANSWER:
levonordefrin// (Neo-Cobefrin)/ / -// ANSWER:// Vasoconstrictor//
1/6th// as// strong// as// EPI
Mostly// act// on// Alpha// receptors// (75%)// Beta// (25%)//
Less// systemic// effects// than// EPI
Max// Dose// in// ALL// Pt's// =// 1mg/appt// =// 11// cartridges
2%// carbocaine// with// 1:20,000// Levonordefrin
inact/ / -// ANSWER:// To// bring// into// action// or// a// state// of// activity.
Pain// threshold// pertains// to// the// point// at// which// a// sensation// starts// to// be// painful// and//
discomfort// results.// This// threshold// varies// among// individuals// and// may// be// altered// by// some//
drugs// such// as// local// anesthesia./ / -// ANSWER:// Many// patients// fear// the// dental// provider//
because// they// are// apprehensive// about// a// "dental// shot."
Local// anesthetics// are// known// as// membrane-stabilizing// drugs,// which// work// by// decreasing//
the// rate// of// depolarization// when// a// membrane// potential// is// initiated./ / -// ANSWER:// When//
neurons// are// firing// quickly,// causing// sodium// channels// to// be// in// their// activated// state,// the//
local// anesthetic// drugs// bind// easier// to// the// sodium// channels,// increasing// the// onset// of//
neuronal// blockade.// This// phenomenon// is// called// state// dependent// blockade
Nissl// substance// is// a// basophilic// material// primarily// composed// of// ribonucleic// acid// (RNA)//
and// proteins// in// aggregate// with// rough// endoplasmic// reticulum.// This// substance// is// involved//
in// protein// synthesis// and// cellular// metabolism.// Nissl// substance// can// vary// in// quantity,// form,//
and/ / distribution// in// different// types// of// neurons./ / -// ANSWER:
breech-loading// aspirating// syringe/ / -// ANSWER:
Page// 3// of// 62
, Vazirani-Akinosi// mandibular// block/ / -// ANSWER:// include// the// IN,// lingual,// mental,//
incisve,// and// mylohyoid// nerves// within// the// pterygomandibular// space// and// long// buccal//
nerve// approximately// 75%// of// the// time
Morphine/ / -// ANSWER:// narcotic// drug// derived// from// opium,// used// to// treat// severe// pain//
Helothane/ / -// ANSWER:
Procaine// (Novocain)/ / -// ANSWER:// used// as// an// anasthetic,// derived// from// the// coca// plant
Myelin// (lipoprotein// sheath)// is// composed// of// about// 75%// lipid,// about// 20%// protein,// and//
about// 5%// carbohydrates.// Myelin// is// made// up// primarily// of// a// glycolipid// called//
galactocerebroside// and// almost// completely// insulates// the// axon// from// the// outside./ / -//
ANSWER:
Unmyelinated// fibers// and// myelinated// axons// of// the// CNS// do// not// regenerate.// The//
demyelination// of// axons// is// the// cause// of// the// multitude// of// neurologic// symptoms// seen// in//
multiple// sclerosis./ / -// ANSWER:
saltatory// conduction/ / -// ANSWER:// Rapid// transmission// of// a// nerve// impulse// along// an//
axon,// resulting// from// the// action// potential// jumping// from// one// node// of// Ranvier// to// another,//
skipping// the// myelin-sheathed// regions// of// membrane.
Unmyelinated// nerves// are// free// nerve// endings;// the// smallest// nerve// fibers// are// also// known// as//
C// fibers.// C// fibers// are// the// most// numerous// fiber// type// in// the// PNS./ / -// ANSWER:
Peripheral// nerve// fibers// differ// substantially// and// can// be// classified// based// on// axonal//
conduction// velocity,// frequency// of// firing,// degree// of// myelination,// and// fiber// diameter./ / -//
ANSWER:// For// example,// there// are// slow-conducting// unmyelinated// C// fibers// and// faster-
conducting// myelinated// Aδ// fibers.// All// these// factors// influence// the// ability// of// the// local//
anesthetic// to// block// the// nerve// conduction.
Type// A// fibers// are// the// largest// fibers// present// in// mammalian// nerves,// and// with// the// rate// of//
impulse// transmission// directly// proportional// to// fiber// diameter,// this// group// comprises// the//
most// rapidly// conducting// axons./ / -// ANSWER:// They// are// responsible// for// conducting//
pressure// and// motor// sensations.Type// A// fibers// are// further// divided// into// four// groups,// α//
through// δ.// Aδ// fibers
Page// 4// of// 62
Second Edition Demetra Daskalos Logothetis, RDH, MS
Professor Emeritus and Graduate Program Director
Department of Dental Medicine University of New Mexico,
Albuquerque, New Mexico Educational Consultant, Albuquer
Acetylsalicylic// Acid// (Aspirin)/ / -// ANSWER:// ASA//
antipyretic/ / -// ANSWER:// reduces// fever// (Tylenol,// aspirin)
Epinephrine// is// naturally// secreted// by// the// adrenal// glands// and// the// sympathetic// nerve// fibers.//
The// hormone// can// be// obtained// via// extraction// from// the// adrenal// glands// of// cattle// and//
sheep,// or// it// can// be// made// in// a// laboratory.// Synthetic// production// of// epinephrine// entails// the//
reaction// of// catechol// and// chloroacetyl// chloride./ / -// ANSWER:
antipyretic/ / -// ANSWER:// reduces// fever// (Tylenol,// aspirin)
In// 1842,// it// was// reported// that// William// Clarke// administered// ether,// via// a// towel,// to// a// woman//
as// one// ofher// teeth// was// extracted// by// a// dentist./ / -// ANSWER:
Tagamet// (cimetidine)// decreases// hepatic// blood// flow// and// inhibits// hepatic// metabolism// of//
amides,// particularly// lidocaine,// by// competing// for// binding// to// hepatic// oxidative// enzymes,//
and// therefore// increases// half// life// of// the// amide// anesthetic,// augmenting// the// risk// for// toxic//
overdose./ / -// ANSWER:
Morphine/ / -// ANSWER:// narcotic// drug// derived// from// opium,// used// to// treat// severe// pain
Horace// Wells,// a// dentist,// first// tried// nitrous// oxide// for// dental// pain// control// after// attending//
several// "laughing// gas"// parties./ / -// ANSWER:
He// practiced// on// himself// by// using// nitrous// oxide,// which// he// considered// safer// than// ether,//
and// had// a// fellow// dentist// extract// his// tooth.He// felt// nothing// during// the// extraction// and//
discovered// nitrous// oxide// to// be// an// effective// anesthetic./ / -// ANSWER:
Page// 1// of// 62
,Halothane,// a// safe// and// stable// chemical// for// inhalation// anesthesia,// was// introduced// in// 1956./ /
-// ANSWER:
Halothane// (Fluothane)/ / -// ANSWER:// halogenated// hydrocarbon// volatile// liquid//
anesthetic// with// good// maintenance
The// first// local// anesthetic,// cocaine,// was// isolated// from// coca// leaves// by// Albert// Niemann// and//
Francesco// Di// Stefano// in// Germany// in// the// 1860s./ / -// ANSWER:
Cocaine// was// first// used// as// a// local// anesthetic// in// 1884// by// Karl// Koller,// who// demonstrated//
the// use// during// painless// ophthalmological// surgery./ / -// ANSWER:
In// 1905,// the// ester// procaine// (Novocaine)// was// created// in// Germany// and,// when// mixed// with// a//
proportion// of// epinephrine,// was// found// to// be// effective// and// safe/ / -// ANSWER:
Procaine// took// a// long// time// to// produce// the// desired// anesthetic// result,// wore// off// quickly,// and//
was// not// as// potent// as// cocaine.// Additionally,// many// patients// were// allergic// to// procaine//
because// procaine// is// an// ester// that// has// a// high// potential// for// allergic// reactions./ / -//
ANSWER:
In// the// 1940s,// a// new// group// of// local// anesthetic// compounds,// the// amides,were// introduced.//
The// initial// amide// local// anesthetic,// lidocaine,// was// synthesized// by// the// Swedish// chemist//
Nils// Lofgren// in// 1943./ / -// ANSWER:// Lidocaine// revolutionized// pain// control// in//
dentistry// worldwide,// because// it// was// both// more// potent// and// less// allergenic// than// procaine.//
In// the// succeeding// years,// other// amide// local// anesthetics// (prilocaine// in// 1959,// bupivacaine//
and// mepivacaine// in// 1957)// were// introduced.
These// new// amide// local// anesthetics// provided// the// dental// practitioner// with// an// array// of//
local// anesthetics// for// pulpal// anesthesia// that// could// last// from// 20// minutes// (mepivacaine//
plain)// to// 3// hours// (bupivacaine// with// epinephrine)/ / -// ANSWER:
In// 1969,// Rusching// and// colleagues// prepared// a// new// drug,// carticaine,// which// differed// from//
the// previous// amide// local// anesthetics/ / -// ANSWER:// Renamed// articaine// in// 1984,// the//
drug// was// derived// from// thiophene// and// thus// contained// a// thiophene// ring// in// its// molecule//
instead// of// the// usual// benzene// ring.// Articaine// became// available// in// 2000// for// marketing// in//
the// United// States// in// a// 4%// 1:100,000// epinephrine// formulation.
Page// 2// of// 62
,Today,// lidocaine// remains// the// most// popular// anesthetic// used// in// dentistry// in// the// United//
States;// however,articaine// is// increasing// in// its// popularity// and// is// a// close// second// to//
lidocaine.Many// patients// do// not// understand// the// distinction// among// the// agents// and// still//
ask// for// Novocaine,// which// is// no// longer// available// in// dentistry./ / -// ANSWER:
levonordefrin// (Neo-Cobefrin)/ / -// ANSWER:// Vasoconstrictor//
1/6th// as// strong// as// EPI
Mostly// act// on// Alpha// receptors// (75%)// Beta// (25%)//
Less// systemic// effects// than// EPI
Max// Dose// in// ALL// Pt's// =// 1mg/appt// =// 11// cartridges
2%// carbocaine// with// 1:20,000// Levonordefrin
inact/ / -// ANSWER:// To// bring// into// action// or// a// state// of// activity.
Pain// threshold// pertains// to// the// point// at// which// a// sensation// starts// to// be// painful// and//
discomfort// results.// This// threshold// varies// among// individuals// and// may// be// altered// by// some//
drugs// such// as// local// anesthesia./ / -// ANSWER:// Many// patients// fear// the// dental// provider//
because// they// are// apprehensive// about// a// "dental// shot."
Local// anesthetics// are// known// as// membrane-stabilizing// drugs,// which// work// by// decreasing//
the// rate// of// depolarization// when// a// membrane// potential// is// initiated./ / -// ANSWER:// When//
neurons// are// firing// quickly,// causing// sodium// channels// to// be// in// their// activated// state,// the//
local// anesthetic// drugs// bind// easier// to// the// sodium// channels,// increasing// the// onset// of//
neuronal// blockade.// This// phenomenon// is// called// state// dependent// blockade
Nissl// substance// is// a// basophilic// material// primarily// composed// of// ribonucleic// acid// (RNA)//
and// proteins// in// aggregate// with// rough// endoplasmic// reticulum.// This// substance// is// involved//
in// protein// synthesis// and// cellular// metabolism.// Nissl// substance// can// vary// in// quantity,// form,//
and/ / distribution// in// different// types// of// neurons./ / -// ANSWER:
breech-loading// aspirating// syringe/ / -// ANSWER:
Page// 3// of// 62
, Vazirani-Akinosi// mandibular// block/ / -// ANSWER:// include// the// IN,// lingual,// mental,//
incisve,// and// mylohyoid// nerves// within// the// pterygomandibular// space// and// long// buccal//
nerve// approximately// 75%// of// the// time
Morphine/ / -// ANSWER:// narcotic// drug// derived// from// opium,// used// to// treat// severe// pain//
Helothane/ / -// ANSWER:
Procaine// (Novocain)/ / -// ANSWER:// used// as// an// anasthetic,// derived// from// the// coca// plant
Myelin// (lipoprotein// sheath)// is// composed// of// about// 75%// lipid,// about// 20%// protein,// and//
about// 5%// carbohydrates.// Myelin// is// made// up// primarily// of// a// glycolipid// called//
galactocerebroside// and// almost// completely// insulates// the// axon// from// the// outside./ / -//
ANSWER:
Unmyelinated// fibers// and// myelinated// axons// of// the// CNS// do// not// regenerate.// The//
demyelination// of// axons// is// the// cause// of// the// multitude// of// neurologic// symptoms// seen// in//
multiple// sclerosis./ / -// ANSWER:
saltatory// conduction/ / -// ANSWER:// Rapid// transmission// of// a// nerve// impulse// along// an//
axon,// resulting// from// the// action// potential// jumping// from// one// node// of// Ranvier// to// another,//
skipping// the// myelin-sheathed// regions// of// membrane.
Unmyelinated// nerves// are// free// nerve// endings;// the// smallest// nerve// fibers// are// also// known// as//
C// fibers.// C// fibers// are// the// most// numerous// fiber// type// in// the// PNS./ / -// ANSWER:
Peripheral// nerve// fibers// differ// substantially// and// can// be// classified// based// on// axonal//
conduction// velocity,// frequency// of// firing,// degree// of// myelination,// and// fiber// diameter./ / -//
ANSWER:// For// example,// there// are// slow-conducting// unmyelinated// C// fibers// and// faster-
conducting// myelinated// Aδ// fibers.// All// these// factors// influence// the// ability// of// the// local//
anesthetic// to// block// the// nerve// conduction.
Type// A// fibers// are// the// largest// fibers// present// in// mammalian// nerves,// and// with// the// rate// of//
impulse// transmission// directly// proportional// to// fiber// diameter,// this// group// comprises// the//
most// rapidly// conducting// axons./ / -// ANSWER:// They// are// responsible// for// conducting//
pressure// and// motor// sensations.Type// A// fibers// are// further// divided// into// four// groups,// α//
through// δ.// Aδ// fibers
Page// 4// of// 62
