Lecture 6Lecture 6Measuring dental Measuring dental

cariescaries..

Prof. Ahmed Prof. Ahmed AbdelrahmmanAbdelrahmman

EXAMINATION OF DENTAL EXAMINATION OF DENTAL CARIESCARIES :- :-

TYPE I :-TYPE I :- complete examination complete examination..TYPE II :-TYPE II :- limited examination limited examination..TYPE III :-TYPE III :- mirror & explorer and mirror & explorer and

source of illuminationsource of illumination..TYPE IV :-TYPE IV :- screening procedures, screening procedures,

using only a tongue depressor and using only a tongue depressor and available illuminationavailable illumination..

Diagnostic criteria of cariesDiagnostic criteria of caries :- :- According to the WHO ( 1997 ) :-According to the WHO ( 1997 ) :- any signs that precede any signs that precede cavitationscavitations as as

well as other conditions similar to the well as other conditions similar to the early stage of caries are early stage of caries are excludedexcluded as it as it can be treated in can be treated in noninvasive noninvasive way.way.

White or chalky spots.White or chalky spots. Discolored or rough spots that are not soft Discolored or rough spots that are not soft

to touch with probeto touch with probe Stained pits or fissures with no under Stained pits or fissures with no under

mined enamel.mined enamel. Dark, shiny, hard pitted areas of enamel.Dark, shiny, hard pitted areas of enamel.

Decayed crownDecayed crown :- :-dental caries is recorded as dental caries is recorded as presentpresent when when

a lesion in a pit or fissure or on smooth a lesion in a pit or fissure or on smooth surface hassurface has :- :-

A cavity, undermined enamel or detectably A cavity, undermined enamel or detectably softened floor or wallsoftened floor or wall..

A tooth with temporary filling should be A tooth with temporary filling should be included in this categoryincluded in this category..

Missing teeth:-Missing teeth:- as a result of caries as a result of caries should be only recordedshould be only recorded

Measurement of the intensity of Measurement of the intensity of dental caries have been used dental caries have been used since the early 20since the early 20thth century. century.

ProportionProportion of 1 of 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.

DMF IndexDMF Index..

Attributed to Attributed to Klein, PalmerKlein, Palmer and and KnustonKnuston in the 1930 in the 1930’’s. Since then,s. Since then, DMF index has received practicallyDMF index has received practically universal acceptance and probably universal acceptance and probably

the best known of all dental indexes.the best known of all dental indexes.

Characteristics of DMF Characteristics of DMF Index:-Index:-

The DMF, an The DMF, an irreversible irreversible index, index, applied only to permanent teeth. And applied only to permanent teeth. And always significant by upper case always significant by upper case letters.letters.

D D was decayed teethwas decayed teeth, M, M, teeth , teeth missing due to caries, and missing due to caries, and F,F, teeth teeth that had been previously filled.that had been previously filled.

DMF score for any one individual can DMF score for any one individual can range range from 0 to 32from 0 to 32 in whole number. in whole number.

A mean DMF score for a group, being A mean DMF score for a group, being the total of individual values divided the total of individual values divided by the number of subjects examined, by the number of subjects examined, can have can have fractional valuesfractional values..

The DMF index can be applied to The DMF index can be applied to whole teethwhole teeth (designated as (designated as DMFTDMFT) or ) or to surfacesto surfaces ( (DMFS)DMFS) which is more which is more sensitive, used in the clinical trials.sensitive, used in the clinical trials.

To To save timesave time in a large survey, DMF in a large survey, DMF can be used can be used half-mouthhalf-mouth and the and the score doubled, an approach that score doubled, an approach that assume the bilateral nature of caries.assume the bilateral nature of caries.

Modification.Modification.

Teeth that have been filled and have Teeth that have been filled and have redecayedredecayed on another surface, so on another surface, so better to use DMFS.better to use DMFS.

Secondary cariesSecondary caries around an existing around an existing restoration.restoration.

Crowned teethCrowned teeth and bridge pontic. and bridge pontic.

Indexes for primary teeth:-Indexes for primary teeth:-

The equivalent index for the The equivalent index for the primary dentition is the primary dentition is the defdef and and its modifications, signified by its modifications, signified by lower caselower case letters. letters.

Characteristics of def index:-Characteristics of def index:-

The The dd stood for decayed teeth, stood for decayed teeth, ee means indicated for extraction, and means indicated for extraction, and f f was filled teeth.was filled teeth.

Teeth missingTeeth missing for caries are not for caries are not recorded coz of the difficulty of recorded coz of the difficulty of distinguishing between distinguishing between extracted extracted and and naturally naturally exfoliatedexfoliated primary teeth. primary teeth.

Modifications of def:-Modifications of def:-

The The dmf dmf index for use in children index for use in children before before ages of exfoliation.ages of exfoliation.

It applied only to primary molars.It applied only to primary molars.

The The dfdf index in which missing teeth index in which missing teeth are ignored.are ignored.

The The dfdf and and defdef should be should be numericallynumerically the same.the same.

Both understate the true extent of Both understate the true extent of carious attack.carious attack.

Limitations of DMF index:-Limitations of DMF index:-

DMFDMF values are not related to the values are not related to the number of number of teeth at risk.teeth at risk.

It has It has no denominator.no denominator.

Have little meaning unless Have little meaning unless age age is is also stated.also stated.

It can be It can be invalidinvalid in older adults. in older adults.

It can be It can be misleadingmisleading in children in children……

It can be It can be over estimateover estimate caries caries experience in teeth with experience in teeth with Preventive Preventive RestorationsRestorations……....DMF score will beDMF score will be inflated.inflated.

DMF cannot used for DMF cannot used for root caries.root caries.

DMF cannot account for DMF cannot account for sealed teethsealed teeth..

Criteria for diagnosing Root Criteria for diagnosing Root Surface Caries:-Surface Caries:-

DiscreteDiscrete well defined & well defined & discolored discolored soft area.soft area.

Explorer enters easilyExplorer enters easily displays some displays some resistanceresistance to withdrawal. to withdrawal.

The lesion is located either at the The lesion is located either at the CEJCEJ OR wholly on the OR wholly on the root surfaceroot surface..

Root caries index ( RCI ) :-Root caries index ( RCI ) :-

As described by As described by Katz,1980,Katz,1980, a tooth is a tooth is considered to be at risk of root caries considered to be at risk of root caries if--->if--->

Enough Enough gingival recessiongingival recession has has occurred to expose part of the occurred to expose part of the cement surface to the cement surface to the oral oral environment.environment.

RCI =RCI =

Root surface :decayed + filledRoot surface :decayed + filled Root surface :d+ f+ soundRoot surface :d+ f+ sound

x100x100

A community A community RCI of 6.91RCI of 6.91 means that means that

all teeth with all teeth with gingival recessiongingival recession, 6.9% , 6.9% were decayed or filled on the root were decayed or filled on the root surface.surface.

DT = 1DS = 2

DT = 1DS = 3

DT = 1DS = 1

Following the Following the ingestion ofingestion of fermentable carbohydratesfermentable carbohydrates, the pH of , the pH of the plaque drops rapidly to a point the plaque drops rapidly to a point where demineralization begins; where demineralization begins; usually in a range between usually in a range between pH 5.5 and pH 5.5 and

5.05.0..

pH 5.5

pH 5.0pH

Time

Normal plaque pH

Demineralization: calcium & phosphate ions leaching out at the plaque enamel interface at pH 5

.

CaCa

CaCa CaPO4

PO4 PO4 PO4

PO4PO4

EnamelDemineralized

area

Dental plaqueSaliva pH = 5

Ca

(1)(1)

Inward flow of calcium and phosphate ions (remineralization) favoured by fluoride ions at pH 7.

F

FF

F

PO4

PO4 PO4

PO4

PO4 Ca

Ca

Ca

Ca

Ca

EnamelRemineralized area

Saliva pH = 7

(2)(2)

Demin. DeminRemin.Remin

When demineralization exceeds remineralization dental caries occurs

Dynamic equilibrium

= no cariesDemin. Exceeds remin.

= caries occurs

Carious lesionCarious lesion beginsbegins as a clinically as a clinically undetectable undetectable subsurfacesubsurface demineralization of enamel visible only demineralization of enamel visible only

at microscopic levelat microscopic level..

Non-cavitated lesion Cavitated lesion

Initial stagesInitial stages of dental caries are of dental caries are reversiblereversible..

As long as the lesion is still incipient As long as the lesion is still incipient i.e. with no cavitations i.e. with no cavitations

remineralization is possibleremineralization is possible..

The early identification of such early The early identification of such early carious lesion is carious lesion is extremely extremely importantimportant because it is during this because it is during this stage that the carious process can be stage that the carious process can be

arrested or reversedarrested or reversed . .

Treatment is by primary Treatment is by primary preventivepreventive practices such as practices such as plaque controlplaque control and and

topical fluoridetopical fluoride applications applications..

On the other handOn the other hand, , the overt the overt

cavitations stage is cavitations stage is an an irreversible irreversible oneone..

It may be called It may be called ““ thethe point of no point of no

returnreturn" as it is no " as it is no longer expected longer expected

that that remineralization remineralization

can occurcan occur..

Criteria from WHO guidelinesCriteria from WHO guidelines;;Caries is recorded as present when a lesion in a Caries 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 cavity22- - Undermined enamelUndermined enamel33- - Softened floor or wallSoftened floor or wall44- - On a proximal surfaces , the examiner must be On a proximal surfaces , the examiner must be

certain that the explorer entered a lesioncertain that the explorer entered a lesion..55- - A A tooth with temporary filling should be included tooth with temporary filling should be included

in this categoryin this category..

Where any Where any doubtdoubt exists, the surface exists, the surface is recorded is recorded as as soundsound..

Scored as sound by WHO criteria

Thus, Thus, a tooth with the following a tooth with the following criteria should be coded as criteria should be coded as

soundsound::

11- - White or chalkyWhite or chalky spots spots..

22- - Discolored or rough spotsDiscolored or rough spots that are that 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 the in the enamel that do not have visual signs enamel that do not have visual signs of undermined enamel, or softening of undermined enamel, or softening

of the floor or wallof the floor or wall..

Diagnostic Criteria for non-cavitated Diagnostic Criteria for non-cavitated lesionslesions

The The first visual evidencefirst visual evidence of an incipient of an incipient lesion on enamel surface the appearance lesion on enamel surface the appearance

of a of a white spotwhite spot..By time it may become a By time it may become a brownbrown spot spot..

On On buccal & lingualbuccal & lingual surfaces, the surfaces, the white spot may be white spot may be localizedlocalized or it can or it can extend extend parallel to the gingival parallel to the gingival

marginmargin..

Traditionally Traditionally 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 toward moved more toward exclusively visualexclusively visual methodmethod

(i.e. without probing(i.e. without probing( (

–Mouth mirrorMouth mirror–Good illuminationGood illumination

Explorer should not be usedExplorer should not be used for several reasonsfor several reasons::

11--the the use of exploreruse of explorer ,even gentle ,even gentle probing with a sharp explorer, is probing with a sharp explorer, is

likely to likely to damage the surfacedamage the surface zonezone of of non-cavitated lesionsnon-cavitated lesions..

Even gentle probing Even gentle probing with a sharp explorer with a sharp explorer

turned turned non-cavitated

lesion into into cavitationcavitation..thus thus turningturning what could have been a what could have been a reversiblereversible lesion (non-cavitated) lesion (non-cavitated) intointo one that is one that is irreversibleirreversible..

22- - It may provide It may provide no more accuracyno more accuracy in diagnosis in diagnosis becausebecause the surface the surface

enamel of non-cavitated lesions enamel of non-cavitated lesions feels feels hardhard and give no indication for and give no indication for

demineralizationdemineralization..

33- - It may allow It may allow transmission of transmission of cariogeniccariogenic bacteria from infected bacteria from infected

sitessites..