1. Lecture 6Lecture 6
Measuring dentalMeasuring dental
cariescaries..
Prof. AhmedProf. Ahmed
AbdelrahmmanAbdelrahmman

2. EXAMINATION OF DENTALEXAMINATION OF DENTAL
CARIESCARIES:-:-
TYPE I :-TYPE I :- complete examinationcomplete examination..
TYPE II :-TYPE II :- limited examinationlimited examination..
TYPE III :-TYPE III :- mirror & explorer andmirror & explorer and
source of illuminationsource of illumination..
TYPE IV :-TYPE IV :- screening procedures,screening procedures,
using only a tongue depressor andusing only a tongue depressor and
available illuminationavailable illumination..

3. Diagnostic criteria of cariesDiagnostic criteria of caries:-:-
 According to the WHO ( 1997 ) :-According to the WHO ( 1997 ) :-
 any signs that precedeany signs that precede cavitationscavitations asas
well as other conditions similar to thewell as other conditions similar to the
early stage of caries areearly stage of caries are excludedexcluded as itas it
can be treated incan be treated in noninvasivenoninvasive way.way.
 White or chalky spots.White or chalky spots.
 Discolored or rough spots that are not softDiscolored or rough spots that are not soft
to touch with probeto touch with probe
 Stained pits or fissures with no underStained pits or fissures with no under
mined enamel.mined enamel.
 Dark, shiny, hard pitted areas of enamel.Dark, shiny, hard pitted areas of enamel.

4. Decayed crownDecayed crown:-:-
dental caries is recorded asdental caries is recorded as presentpresent whenwhen
a lesion in a pit or fissure or on smootha lesion in a pit or fissure or on smooth
surface hassurface has:-:-
A cavity, undermined enamel or detectablyA cavity, undermined enamel or detectably
softened floor or wallsoftened floor or wall..
A tooth with temporary filling should beA tooth with temporary filling should be
included in this categoryincluded in this category..
Missing teeth:-Missing teeth:- as a result of cariesas a result of caries
should be only recordedshould be only recorded

5.  Measurement of the intensity ofMeasurement of the intensity of
dental caries have been useddental caries have been used
since the early 20since the early 20thth
century.century.
 ProportionProportion of 1of 1stst
molar lost through caries.molar lost through caries.
 PercentagePercentage of permanent teeth affected.of permanent teeth affected.
Both methods were not sensitive.Both methods were not sensitive.

6. DMF IndexDMF Index..
 Attributed toAttributed to Klein, PalmerKlein, Palmer andand
 KnustonKnuston in the 1930in the 1930’’s. Since then,s. Since then,
 DMF index has received practicallyDMF index has received practically
 universal acceptance and probablyuniversal acceptance and probably
the best known of all dental indexes.the best known of all dental indexes.

7. Characteristics of DMFCharacteristics of DMF
Index:-Index:-
 The DMF, anThe DMF, an irreversibleirreversible index,index,
applied only to permanent teeth. Andapplied only to permanent teeth. And
always significant by upper casealways significant by upper case
letters.letters.
 DD was decayed teethwas decayed teeth, M, M, teeth, teeth
missing due to caries, andmissing due to caries, and F,F, teethteeth
that had been previously filled.that had been previously filled.

8.  DMF score for any one individual canDMF score for any one individual can
rangerange from 0 to 32from 0 to 32 in whole number.in whole number.
 A mean DMF score for a group, beingA mean DMF score for a group, being
the total of individual values dividedthe total of individual values divided
by the number of subjects examined,by the number of subjects examined,
can havecan have fractional valuesfractional values..

9.  The DMF index can be applied toThe DMF index can be applied to
whole teethwhole teeth (designated as(designated as DMFTDMFT) or) or
to surfacesto surfaces ((DMFS)DMFS) which is morewhich is more
sensitive, used in the clinical trials.sensitive, used in the clinical trials.
 ToTo save timesave time in a large survey, DMFin a large survey, DMF
can be usedcan be used half-mouthhalf-mouth and theand the
score doubled, an approach thatscore doubled, an approach that
assume the bilateral nature of caries.assume the bilateral nature of caries.

10. Modification.Modification.
 Teeth that have been filled and haveTeeth that have been filled and have
redecayedredecayed on another surface, soon another surface, so
better to use DMFS.better to use DMFS.
 Secondary cariesSecondary caries around an existingaround an existing
restoration.restoration.
 Crowned teethCrowned teeth and bridge pontic.and bridge pontic.

11. Indexes for primary teeth:-Indexes for primary teeth:-
The equivalent index for theThe equivalent index for the
primary dentition is theprimary dentition is the defdef andand
its modifications, signified byits modifications, signified by
lower caselower case letters.letters.

12. Characteristics of def index:-Characteristics of def index:-
 TheThe dd stood for decayed teeth,stood for decayed teeth, ee
means indicated for extraction, andmeans indicated for extraction, and ff
was filled teeth.was filled teeth.
 Teeth missingTeeth missing for caries are notfor caries are not
recorded coz of the difficulty ofrecorded coz of the difficulty of
distinguishing betweendistinguishing between extractedextracted andand
naturallynaturally exfoliatedexfoliated primary teeth.primary teeth.

13. Modifications of def:-Modifications of def:-
 TheThe dmfdmf index for use in childrenindex for use in children
beforebefore ages of exfoliation.ages of exfoliation.
 It applied only to primary molars.It applied only to primary molars.
 TheThe dfdf index in which missing teethindex in which missing teeth
are ignored.are ignored.

14.  TheThe dfdf andand defdef should beshould be numericallynumerically
the same.the same.
 Both understate the true extent ofBoth understate the true extent of
carious attack.carious attack.

15. Limitations of DMF index:-Limitations of DMF index:-
 DMFDMF values are not related to thevalues are not related to the
number ofnumber of teeth at risk.teeth at risk.
 It hasIt has no denominator.no denominator.
 Have little meaning unlessHave little meaning unless ageage isis
also stated.also stated.

16.  It can beIt can be invalidinvalid in older adults.in older adults.
 It can beIt can be misleadingmisleading in childrenin children……
 It can beIt can be over estimateover estimate cariescaries
experience in teeth withexperience in teeth with PreventivePreventive
RestorationsRestorations……....DMF score will beDMF score will be
inflated.inflated.

17.  DMF cannot used forDMF cannot used for root caries.root caries.
 DMF cannot account forDMF cannot account for sealed teethsealed teeth..

18. Criteria for diagnosing RootCriteria for diagnosing Root
Surface Caries:-Surface Caries:-
 DiscreteDiscrete well defined &well defined & discoloreddiscolored
soft area.soft area.
 Explorer enters easilyExplorer enters easily displays somedisplays some
resistanceresistance to withdrawal.to withdrawal.
 The lesion is located either at theThe lesion is located either at the CEJCEJ
OR wholly on theOR wholly on the root surfaceroot surface..

19. Root caries index ( RCI ) :-Root caries index ( RCI ) :-
 As described byAs described by Katz,1980,Katz,1980, a tooth isa tooth is
considered to be at risk of root cariesconsidered to be at risk of root caries
if--->if--->
 EnoughEnough gingival recessiongingival recession hashas
occurred to expose part of theoccurred to expose part of the
cement surface to thecement surface to the oraloral
environment.environment.

20.  RCI =RCI =
 Root surface :decayed + filledRoot surface :decayed + filled
 Root surface :d+ f+ soundRoot surface :d+ f+ sound
x100x100

21.  A communityA community RCI of 6.91RCI of 6.91 means thatmeans that
all teeth withall teeth with gingival recessiongingival recession, 6.9%, 6.9%
were decayed or filled on the rootwere decayed or filled on the root
surface.surface.

22. DT = 1
DS = 2
DT = 1
DS = 3
DT = 1
DS = 1

23. Following theFollowing the ingestion ofingestion of
fermentable carbohydratesfermentable carbohydrates, the pH of, the pH of
the plaque drops rapidly to a pointthe plaque drops rapidly to a point
where demineralization begins;where demineralization begins;
usually in a range betweenusually in a range between pH 5.5 andpH 5.5 and
5.05.0..
pH 5.5
pH 5.0
pH
Time
Normal plaque pH

24. Demineralization: calcium & phosphate ions
leaching out at the plaque enamel interface at pH 5
.
Ca
Ca
CaCa CaPO4
PO4 PO4
PO4
PO4PO4
Enamel
Demineralized
area
Dental plaque
Saliva pH = 5
Ca
(1)(1)

25. Inward flow of calcium and phosphate ions
(remineralization) favoured by fluoride ions at pH 7.
F
F
F
F
PO4
PO4 PO4
PO4
PO4
Ca
Ca
Ca
Ca
Ca
EnamelRemineralized area
Saliva pH = 7
(2)(2)

26. Demin.
DeminRemin.
Remin
When demineralization exceeds
remineralization dental caries occurs
Dynamic equilibrium
= no caries
Demin. Exceeds remin.
= caries occurs

27. Carious lesionCarious lesion beginsbegins as a clinicallyas a clinically
undetectableundetectable subsurfacesubsurface
demineralization of enamel visible onlydemineralization of enamel visible only
at microscopic levelat microscopic level..

29. Non-cavitated lesion Cavitated lesion

30. Initial stagesInitial stages of dental caries areof dental caries are
reversiblereversible..
As long as the lesion is still incipientAs long as the lesion is still incipient
i.e. with no cavitationsi.e. with no cavitations
remineralization is possibleremineralization is possible..
The early identification of such earlyThe early identification of such early
carious lesion iscarious lesion is extremelyextremely
importantimportant because it is during thisbecause it is during this
stage that the carious process can bestage that the carious process can be
arrested or reversedarrested or reversed..

31. Treatment is by primaryTreatment is by primary preventivepreventive
practices such aspractices such as plaque controlplaque control andand
topical fluoridetopical fluoride applicationsapplications..

32. On the other handOn the other hand,,
the overtthe overt
cavitations stage iscavitations stage is
anan irreversibleirreversible oneone..
It may be calledIt may be called ““
thethe point of nopoint of no
returnreturn" as it is no" as it is no
longer expectedlonger expected
thatthat
remineralizationremineralization
can occurcan occur..

33. Criteria from WHO guidelinesCriteria from WHO guidelines;;
Caries is recorded as present when a lesion in aCaries is recorded as present when a lesion in a
pit or a fissure or on a smooth surface haspit or a fissure or on a smooth surface has::
11--Obvious cavityObvious cavity
22--Undermined enamelUndermined enamel
33--Softened floor or wallSoftened floor or wall
44--On a proximal surfaces , the examiner must beOn a proximal surfaces , the examiner must be
certain that the explorer entered a lesioncertain that the explorer entered a lesion..
55--AA tooth with temporary filling should be includedtooth with temporary filling should be included
in this categoryin this category..
Where anyWhere any doubtdoubt exists, the surfaceexists, the surface is recordedis recorded
asas soundsound..

34. Scored as sound by WHO criteria

35. Thus,Thus, a tooth with the followinga tooth with the following
criteria should be coded ascriteria should be coded as
soundsound::
11--White or chalkyWhite or chalky spotsspots..
22--Discolored or rough spotsDiscolored or rough spots that arethat are
not soft to touch with a blunt probenot soft to touch with a blunt probe..
33--Stained pits or fissuresStained pits or fissures in thein the
enamel that do not have visual signsenamel that do not have visual signs
of undermined enamel, or softeningof undermined enamel, or softening
of the floor or wallof the floor or wall..

36. Diagnostic Criteria for non-cavitatedDiagnostic Criteria for non-cavitated
lesionslesions
TheThe first visual evidencefirst visual evidence of an incipientof an incipient
lesion on enamel surface the appearancelesion on enamel surface the appearance
of aof a white spotwhite spot..
By time it may become aBy time it may become a brownbrown spotspot..

37. OnOn buccal & lingualbuccal & lingual surfaces, thesurfaces, the
white spot may bewhite spot may be localizedlocalized or it canor it can
extendextend parallel to the gingivalparallel to the gingival
marginmargin..

38. TraditionallyTraditionally visual-tactile methodvisual-tactile method is used (i.e.is used (i.e.
explorer as well as visionexplorer as well as vision( .( .
–Mouth mirrorMouth mirror
–ExplorerExplorer
–Good illuminationGood illumination
RecentlyRecently, method for diagnosing caries have, method for diagnosing caries have
moved more towardmoved more toward exclusively visualexclusively visual methodmethod
(i.e. without probing(i.e. without probing((
–Mouth mirrorMouth mirror
–Good illuminationGood illumination

39. Explorer should not be usedExplorer should not be used
for several reasonsfor several reasons::
11--thethe use of exploreruse of explorer ,even gentle,even gentle
probing with a sharp explorer, isprobing with a sharp explorer, is
likely tolikely to damage the surfacedamage the surface zonezone ofof
non-cavitated lesionsnon-cavitated lesions..

40. Even gentle probingEven gentle probing
with a sharp explorerwith a sharp explorer
turnedturned non-cavitated
lesion intointo cavitationcavitation..
thusthus turningturning what could have been awhat could have been a
reversiblereversible lesion (non-cavitated)lesion (non-cavitated) intointo
one that isone that is irreversibleirreversible..

41. 22--It may provideIt may provide no more accuracyno more accuracy
in diagnosisin diagnosis becausebecause the surfacethe surface
enamel of non-cavitated lesionsenamel of non-cavitated lesions feelsfeels
hardhard and give no indication forand give no indication for
demineralizationdemineralization..
33--It may allowIt may allow transmission oftransmission of
cariogeniccariogenic bacteria from infectedbacteria from infected
sitessites..