7/27/2019 Diagnosis of Crack on Tooth

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ENDODONTICS:ColleaguesforExcellenceSummer2008

BonusMaterialC

THEOBVIOUSANDTHEOBSCURE:STEPSFORCRACKDETECTIONANDCONFIRMATION

Ifyoudonotlookforcracksandfracturesinteeth,youwillnotlikelyfindthem.Ifacrackis

suspected,severalstepsshouldbetakentoconfirmthesuspicion.Thetestsperformedand

resultsachievedwillvarybetweenteeththathaveorhavenothadendodontictreatment.

Ifthesuspecttoothhasbeenendodonticallytreated,symptomswillbelimitedtothosecausedby

theaffectedperiodontiumbecausethetoothhasnoremainingvitalpulptissue.Forthetooththat

hasavitalpulp,thefollowingstepswillonlyconfirmthepresenceorabsenceofacrack.Further

pulpalandperiodontaltestingwillbenecessarytodevelopadiagnosisanddeterminetheneed

forendodontictreatment.Remember,cracksinteetharefindings,notdiagnoses.

Thestepstoidentifyacrackorfractureinclude:

DentalHistory SubjectiveExamination ObjectiveVisualExamination TactileExamination PeriapicalTests BiteTests VitalityTesting PeriodontalProbing RadiographicExamination RestorationRemoval Staining Transillumination WedgingForces SurgicalAssessment

Mostofthesetestsarealsonecessarytodeterminepulpaland/orperiapicaldiagnosis;detection

ofcracksanddiagnosisofpulparetwoseparateentities.

DentalHistoryCheckforahistoryof:

Repeatedocclusaladjustmentswithonlytemporaryreliefofsymptomsorevaluationbyseveral

practitioners

without

aconclusive

diagnosis.

Periodontaldiseasewithextensivebonelossinthearea.Decreasedbonesupporthasbeenthoughttoleadtoincreasedstressondentin,predisposingtherootsofatoothto

cracking.

Othercrackedteeth,becausemanyoftheanatomicalandbehavioralfactorsthatpredisposeteethtocracksoftenaffectmorethanonetooth.

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SubjectiveExaminationAskthepatient:

Topointtothetooththatissensitive,keepinginmind,however,thatpatientsmightnotbeabletoidentifytheproblemtooth.

Iftheyrememberaccidentallybitingahardobject.Suchanincidentmaycorrespondtoasuddenonsetofpain.

Aboutanydamaginghabits,suchasclenchingorgrindingtheteeth,orchewingonice,pens,hardcandyorotherobjects.Manypatientshavehadahistoryofhavingacrackin

theirtoothandsomecanhelpyoubymakingtheirowndiagnosis.ObjectiveVisualExaminationCheckthe:

Face,checkingforenlargedjawmuscles,whichmayindicateahabitofoverstressingtheteethduringmastication.Alsolookforwearfacets,whichmayindicateahistoryof

clenching,bruxism,

or

biting

and

chewing

with

excessive

force.

Teethforcuspfossaerelationshipsthatmaycauseexcessiveocclusalstresses.Noteanysteepcuspsordevelopmentalgrooves,becausethesemaypredisposeteethtocracks.

Toothsurfacescarefullyinadryfield.Noteanycrazelinesordarkercracks.Generally,thedarkerthestaininacrack,thelongerthecrackhasbeenpresent.Alsolookfor

crackedrestorationsorunusualgapsbetweenrestorationsandtoothstructure.

Enhancedmagnificationandilluminationcanbehelpfulinvisualidentificationofacrack.

TactileExamination Scratchthesurfaceofthetoothwiththetipofasharpexplorer;thetipmaycatchina

crack.

Palpatethegingivaaroundthetooth,checkingforpossibleevidenceofanunderlyingdehiscenceorfenestration.

PeriapicalTestsPercussionisusuallybeneficialindeterminingwhetheracrackispresentthatinitiatesfromthe

crown.Especiallyhelpfulistheuseofangularpercussion(asopposedtodirectvertical

percussion),whichmaycauseseparationofthecracklineandstimulationofperiodontal

ligament

fibers

or

fluid

movement

in

the

dentinal

tubules.

Palpation,whileaveryhelpfultestforothersituations,isusuallynotbeneficialindetermining

theexistenceofacrack.

BiteTests Usearubberwheel,woodstickorotherinstrumenttofocusbitingpressuresonspecific

cuspstoreproducethepatientscomplaint(speciallydesignedinstrumentsare

commerciallyavailable).

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Placetheinstrumentoneachcusporfossaandhavethepatientbitedownwithmoderatepressureandrelease.Explaintothepatientthattheywillbiteslightly,squeezetightly,

openquickly.

Testseveralteethandcusps;besuretousecontrols. Watchthepatientsfacialexpressionforresponsetopainuponbitingpressureorrelease.

Ifthepatienthasapainfulresponse,askifthepainisthesameasheorshehasbeen

experiencing.

Painduringbitingorchewingisconsideredaclassicsymptomandmaybetheonlyconclusive

evidenceearlyinthecracksdevelopment.Theabsenceofpainduringbiting,however,doesnot

ruleoutthepossibilityofacrack.

VitalityTestingEstablishing

pulp

vitality

determines

the

pulpal

diagnosis,

but

has

little

bearing

on

crack

detection.However,acrackthatextendstothepulpmayallowbacterialcontamination,which

probablyaffectsthepulpstatus.

PeriodontalProbingThoroughprobinginsmallincrementsaroundtheentirecircumferenceofthetoothmayreveala

narrow,isolatedperiodontalprobingdefect,whichischaracteristicofacrack.Iftheprobe

extends8mm,thenthecrackextendsatleast8mm.

Thenarrowpocketthatformsalongacrackwillrestrictsidetosidemotionoftheprobe,making

iteasytodifferentiatefromthebroadbaseddefectcharacteristicofaperiodontaldiseasepocket.

Interproximalprobing

should

be

performed,

especially

if

the

crack

runs

in

amesiodistal

direction.Interproximalrestorationsthatareremovedallowgreateraccesstoperformprobingin

thesedifficultareas.

RadiographicExaminationCracksrarelyarevisualizedonconventionalradiographs.Mesiodistalcrackscanneverbeseen,

andbuccolingualcrackswillonlyappearifthereisactualseparationofthesegmentsorthecrack

happenstobeatexactlythesameangleasthexraybeam.

Changesinthepulpchamber,canalorperiapicalspace,however,maysuggestthepresenceofa

crack.Radiographicevidencetendstobemorelikelyasthecrackprogressesandabonydefect

develops.

Making

periapical

radiographs

from

more

than

one

angle

and

making

bite

wing

radiographsmayincreasethechanceofcatchingacrackinduceddefectearlyinitsdevelopment.

Newertechniques,suchasconebeammicrocomputerizedtomography,willlikelybebeneficial

tononinvasivelydetectthepresenceandextentofcracks.

Athickenedperiodontalligamentspaceoradiffuselongitudinalradiolucency,especiallyone

withanellipticalorJshapedappearanceapicallyalongtheroot,oraUshapedappearance

involvingthefurcationandproximalsurfaces,mayindicateacrack.Checkalsoforrestorations

heldinplacebypins,whichcanpredisposeteethtocracking.

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Inendodonticallytreatedteeth,rarebutsignificantfindingsincludearadiopaquelinewherethe

rootcanalfillingmaterialorsealerhasbeenexpressedintothecrackduringobturation.A

consistentradiolucentlinealongthelengthoftherootcanalfillingmaterialmayindicatespace

causedbyacrack,butshouldnotbeconsideredconclusivebecauseitcouldbecausedbyother

entities.

Thesize,designandplacementofpostsoftencontributetocracks,soitisbesttocheck

endodonticallytreatedteethforlongposts,shortwideposts,custommetalpostsorpostswith

threadsthatbindwithtoothstructure.

Radiographscanalsohelpruleoutotherpossiblediagnoses.Lookforevidenceofperforationsor

internalorexternalresorption.Alsocheckforsignsthatpreviousendodontictreatmentmaybe

recontaminatedwithbacteria.

RestorationRemovalThisallowsvisualexaminationoftheremainingcavity.Carefullycheckthemesialanddistal

marginalridges,

which

tend

to

be

weak

areas.

Magnification,

staining,

transillumination

and

wedgingforcesarehelpfulafterrestorationremoval.

Staining

Cracksmaybedisclosedthroughstaining.Adye,suchasmethyleneblue,canbeappliedtothe

externaltoothsurface,inthecavityafterrestorationremovaloronasurgicallyexposedroot.

TransilluminationIntransillumination,afiberoptictransilluminatororothersimilarlightsource(i.e.,fibeoptic

handpiecewithoutwateroracuringlight)isapplieddirectlytothetoothsurface.Allotherlights

sourcesareeliminated,thetoothisviewedinamirrorandthelightbeamispositioned

perpendicularto

the

plane

of

the

suspected

crack.

A

crack

will

block

the

light.

Structurallysoundteeth,includingthosewithcrazelines,willtransmitthelightthroughoutthe

toothstructure(seeBonusMaterialDformoreinformation).

WedgingForcesAfteracrackisidentified,itisimportanttodetermineifseparabletoothsegmentsexist.

Applicationofwedgingforcesisusedtomakethisdetermination,butonlyafterthepatientis

informedofthepotentialforhearingcrackingnoisesorfeelingpain.

Anyrestorationsareremovedandaninstrumentisplacedinthecavitywithmoderatepressure

exerted

on

opposing

walls

to

try

to

separate

the

segments.

Movement

of

a

tooth

segment

usually

indicatessignificantlydecreasedprognosisunlessdeterminedtobeashallowcuspalfracture

abovethegingivalattachment.

Cliniciansandpatientsmaybehesitanttoperformwedgingofthesegmentsforfearofsplitting

thetoothiatrogenicallyorcausingpain.However,ifcontrolledforceexacerbatesthecrack,

certainlythetoothispredisposedtoalatersplitanyway;thepatientisbestservedtoknowthis

expeditiously.

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SurgicalAssessmentSurgicalexplorationallowsforvisualexaminationoftherootsurfacefortheappearanceofa

crackandshouldonlybeusedifthecrackishighlysuspectedandcannotbeconfirmedbyall

otherpossiblediagnosticmeans.Crackspresentinabuccolingualorientationareeasiertodetect

duringsurgerythanthosethatarepresentinamesiodistalorientation,sincevisualizationis

impededbyadjacentteeth.

Performingdiagnosticsurgery,however,canhelpearlydetectionofuntreatablesituations,

sparingtheneedforendodonticorrestorativetreatmentonanultimatelyhopelesscase.A

consultationwithanendodontistorperiodontistmaybeadvisablepriortosurgicalassessment.

Wheneversurgeryisperformedtodetectacrack,thepatientshouldbefullyinformedthatitis

anexploratorydiagnosticprocedure.