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Tests for prediction and Activity of dentalcaries

Presented by :

Deepti Awasthi

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CONTENTSIntroductionDefinitionObjectivesUses for ClinicianIdeal requisites of caries activity

testTestsConclusionReferences

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INTRODUCTION

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DEFINITIONSCaries activity

Caries susceptibility

Caries activity tests

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ObjectivesIdentify high risk group and individualDetermine need for preventive

measuresTo serve as an index of the success of

the therapeutic measures.To motivate and to monitor the

effectiveness of education programs Manage the progress of restorative

procedures.

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Uses for ClinicianDetermine need for caries control

measureIndicator of patient co-operationAid in timing of recall appointmentsGuide to insertion of expensive

restorationsDetermine the prognosisPrecautionary signal to the

orthodontist in placing bands

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IDEAL REQUISITESSound theoretical basisMaximum correlation with clinical

status.Accurate with respect to duplication of

results.Simple Quick in performance Inexpensive , feasibleValidityReliabilitySensitivity Specificity

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Various caries activity tests

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1. LACTOBACILLUS COLONY COUNT TEST

introduced by HADLEY in 1933

Principle This test measures the number of

acidogenic and aciduric bacteria in patient’s saliva by counting the number of colonies on tomato peptone agar plates after inoculation with a sample of saliva. Cariology , 3rd Ed. -

Earnest Newbrun

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Procedure patient chews a small piece of paraffin

before breakfast The saliva that accumulates in the 3

minute period is collected in a sterile container

Saliva collected is shaken by a machine for 2 minutes

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The saliva sample is diluted with sterile saline solution to 1:100

0.4 ml of each sample is spread on the surface of an agar plate

The plates are incubated for 3 to 4 days at 37°C

The number of Lactobacillus colonies that

develop are counted using Quebec counter.

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Interpretation of LB colony count test

No. of organism CFU/ml

Symbolic designation Degree of caries activity

0-- 1000 + Little or No

1,000– 5000

5000-- 10,000

> 10,000

++

+++

++++

Slight

Moderate

Marked

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Disadvantages

Quick and easy but results are available in days.

Counting colony tedious complex instrument, trained

personnel requiredNot completely exclude the growth

of other relatively aciduric organismsInaccurate for predicting the onset

of caries

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2. Colorimetric SNYDER TEST

SNYDER in 1951

PrincipleTest measures the ability of

salivary microorganisms to form organic acid from a carbohydrate medium

o Bromocresol green indicator dye, changes colour from green to yellow at pH 5.4 to 3.8

Essentials of Preventive and community Dentistry- Soben Peter

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Procedure Salivary sample is collected after the

patient chews a small piece of paraffin before breakfast.

0.2 cc of saliva is pipetted into the

10ml melted agar containing medium in a test tube at 50°C, allowed to solidify and then incubated at 37°C .

The incubation period is upto 72 hours.

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.The media contains :BactopeptoneDextroseSodium chlorideAgarBromocresol green

The rate of colour change from green to yellow is indicative of the degree of caries activity.

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INTERPRETATION TIME

24 hrs 48 hrs 72 hrs

COLOUR YELLOW YELLOW YELLOW

CARIES ACTIVITY MARKED DEFINITE LIMITED

COLOUR GREEN GREEN GREEN

CARIES ACTIVITY CONTINUE TEST CONTINUE TEST INACTIVE

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Advantages : relatively simpleModerate cost

Disadvantages :Time consumingSometimes color change is not

very clearLimited predictive value

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3. THE SWAB TEST GRAINGER et al in 1965.

Principle same as Synder test.

Cariology , 3rd Ed. - Earnest Newbrun

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Procedure

The oral flora is sampled by swabbing the buccal surfaces of the teeth with a cotton applicator,

subsequently incubated in the medium.

The change in the pH following a 48 hour incubation is read on a pH meter or the colour change is read by the use of a colour comparator.

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Interpretation :

pH 4.1 and < 4.1 = Marked caries pH 4.2 to 4.4 = ActivepH 4.5 to 4.6 = Slightly activepH 4.6 and over = Caries inactive

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4. SALIVARY REDUCTASE TEST

measures the activity of the reductase enzyme present in salivary bacteria

This enzyme is involved in the reactions for the formation of products dangerous to the tooth surface.

Rate at which the indicator molecule , diazoresorcinol, changes from blue to red to colorless

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Procedure

Saliva is collected by chewing a special flavoured paraffin and expectorated directly into collection tubes

The sample is then mixed with the dye Diazo-resorcinol

The colour changes and the “Caries Conduciveness” reading is taken after 15 minutes

COLOUR CHANGES

COLOUR CARIES CONDUCIVENESS

Blue 15 minutes

Non – Conducive (1)

Orchid 15 minutes

Slightly Conducive (2)

Red 15 minutes

Moderately Conducive (3)

Red Immediately

Highly Conducive (4)

Pink/white Immediately

Extremely Conducive (5) 25

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Advantages

No incubation Quick results

Disadvantages

Results vary with time after food intake & after brushing

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5.ALBAN TESTSimple modified Snyder test

Main Features: softer medium that permits the

diffusion of saliva and acids without melting the medium.

simpler sampling procedure , patient expectorates directly into tubes containing the medium

Essentials of Preventive and community Dentistry- Soben Peter

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following materials are required:

Synder test agarA small scale to measure 60

grams. A 2 litter Pyrex glass to melt the

medium.A funnel to dispense the medium

into test tubes. 100 - 16 mm test tubes with

screw caps

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Procedure : 60gms of Snyder test agar is placed in 1 litre

of water &suspension is brought to a boil over a low flame.

When thoroughly melted the agar is distributed

The tubes are autoclaved for 15 minutes:

allowed to cool and stored in a refrigerator.

2 tubes are taken & the patient is asked to expectorate a small amount of saliva directly into the tubes.

incubated at 370C for upto 4 days

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observe for:

Change of colour from bluish green (pH 5) to definite yellow (pH 4 or below).

The depth in the medium to which the change has occurred.

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Scale for Scoring:1. No colour change =

‘3/4’2. Beginning colour change = ‘+’ (from top to medium down)3. One half colour change = ‘++’ (from top down)4. Three fourths colour change

= ‘+++’ (from top down)5. Total colour changes to yellow =

‘++++’

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Advantages: Simplicity, Low cost, Diagnostic value when negative

results are obtained. Motivational value Disadvantages:More armamentariumSubjective evaluation

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6. SALIVARY BUFFER CAPACITY

Action Measures the no. of mls of acid

required to lower the pH from 7 to 6. Equipment pH meter0.05N lactic acidParaffinSterile glass jars containing small

amount of oil.

Cariology , 3rd Ed. - Earnest Newbrun

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Procedure

10ml of saliva collected under oil 1hr after eating

5ml is taken into a beakerpH of saliva is adjusted to 7.0Lactic acid is added until pH of

6.0 is reached.The no. of ml of lactic acid

needed to reduce pH is a measure of buffer capacity.

Evaluation :Inverse relationship

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7. STREPTOCOCCUS MUTANS LEVEL IN SALIVA measures the number of

Streptococcus mutans colony forming units per unit volume of saliva

Incubation is done on Mitis Salivarius Agarwith addition of sucrose (20%) & 0.2U bacitracin /ml which supresses the growth of most non-S.Mutans colonies

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Procedure The samples of organisms is

obtained by the use of tongue blades

Sample then pressed against Mitis Salivarius

Bacitracin Agar in special Petri dishes

incubated at 370C for 48 hrs in 95%& 5%CO2

gas mixture Cariology , 3rd Ed. - Earnest Newbrun

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Interpretation : Levels of Streptococcus Mutans > 10 5/ ml of saliva = unacceptable,

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Disadvantages

Difficulty of distinguishing between a carrier state and cariogenic infection.

S. Mutans may constitute less than 1% of total flora of plaque.

S. Mutans tends to be located at specific sites only.

Not convenient for chair side

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8.Dip slide method Dentocult Larmas ,1975S.Mutans levels in saliva

ProcedureSaliva is collected and poured over the agar

coated slide & allowed to dryBacitracin disks are placed in the middle

Co2 tablet is inserted in the tube & then incubated for 48 hrs.

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Colony density (small blue colonies) compared with model chart

0 - negligible1 - <105

2 - 105 - 106

3 - > 106

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9.Plaque / tooth pick method

Action Simple screening of diluted plaque

sample ProcedurePlaque samples are collected from

the gingival thirds of buccal tooth surfaces & placed in Ringer’s solution

Suspension is stretched across MSA plates

Incubation at 370C for 72 hrsCariology , 3rd Ed. - Earnest Newbrun

10. S. mutans adherence method

Saliva inoculated in MSB broth for 24 hrs at 37°C After growth, the supernatant removed Cells adhering to the glass examined macroscopicallySCORE NO OF COLONIES

- No growth expressed

+ Few deposits from 1-10

++ Scattered deposits of smaller size

+++ Numerous minute deposits & more than 20 large deposits (indicates > 105 CFU/ml)

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10.Fosdick Calcium dissolution test

Principle Measures the mgs of powdered

enamel dissolved in 4 hours, when patients saliva mixed with glucose and powdered enamel.

Essentials of Preventive and community Dentistry- Soben Peter

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Advantages Correlation reported is good

Disadvantages Complex equipmentExpensive, trained personnel.

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11. DEWAR TEST

Test similar to fosdick calcium dissolution test

Except that in this test the pH of the mixture is measured instead of the amount of calcium dissolved by the acid.

Essentials of Preventive and community Dentistry- Soben Peter

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12. CARIOSTAT TEST

Tsutomu Shimono 1974

This test has been reported to significantly

correlate with counts of S.mutans in childrenuses a semisynthetic liquid containing

sucrose, tryptose, a gram-negative bacteria growth inhibitor, and bromcresol green and bromcresol purple indicators.

The test assesses acid production by cariogenic bacteria and thus indirectly assesses caries activity

The sensitivity and specificity of a colorimetric microbiological caries activity test (Cariostat) in preschool children

Interpretation of Cariostat test

Score pH Color Caries Activity

0 7

Blue Caries inactive

1 5.5 Green Slight caries

2 4.5 Yellow - Green Moderate caries

3 4.0 Yellow Marked caries

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13.OratestRosenberg et al. in 1989 PrincipleThe rate of oxygen depletion by

micro organisms in expectorated milk samples

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Under aerobic conditions the bacterial enzyme, aerobic dehydrogenase transfers electrons or protons to oxygen.

Once oxygen gets utilized by the aerobic organisms and an anaerobic environment is attained, methylene blue acts as an electron acceptor and gets reduced to leucomethylene blue

The metabolic activity of the aerobic microorganism is reflected by the reduction of methylene blue to leucomethylene blue.

Oratest: A Simple Chairside Aid for Caries Risk Assessment

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Advantages Simple , inexpensive , less time

consuming , reproducible and requiring no trained personnel.

Used to monitor mouth rinse regime , denture hygine , gingival inflammation and plaque levels.

Good educational and motivational tool for patient,school and community health programmes.

Vehicle for test is nontoxic (milk)Anticipate the onset of cariesResults can provide dentist to command

patient to reinforce motivation ,plaque control and behaviour

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Disadvantages It does not identify a specific group

of organism in a specific disease.It cannot accurately differentiate

between the healthy state and between initial and progressive carious lesion

Lack of specificity since positive observation can be obtained in gingivitis and other oral ailments.

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14. Salivary glucosyltransferase bGtfs play a critical role in the

pathogenesis of caries and furthermore, the enzymes are present in whole saliva.

Therefore, hypothesized that the amount of Gtfs collectively or separately could be correlated with caries activity.

chair side and provide results within minutes

Salivary Glucosyltransferase B as a Possible Marker for Caries Activity-

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2 ml of saliva was collectedsaliva was clarified by centrifugation,Clarified saliva was mixed in a 1:1 ratio

with the coating buffer supplied in the kit and was coated onto 96-well plates

After washing, antibodies to Gtf B, C and D were applied

intensity of the color in the wells, which correlated to the amount of purified Gtf present, was read in an ELISA reader

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15. CariScreen Caries Susceptibility Test is done in one minute at chairsideATP bioluminescence technology, which is a test for

light reaction, will measure on a scale from 0 to 9999.

the levels of acid-producing bacteria by swabbing lingual surfaces of lower anterior teeth and then inserting the sample in the CariScreen meter to be read

0 to 1500 is low risk and 1500 to 9999 is high riskThe ATP generates light once it reacts with luciferin,

a light-emitting biological pigment/enzyme present in the CariScreen. The amount of light emission is in direct proportion to the amount of ATP and a well-known fact is that acid-producing bacteria contain 100 times more ATP than non-acid-producing strains

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16. Carivissystem for assessment of caries

activity relies on the unique properties of the Glowdent marker that detects actively occuring dental demineralisation

The amount of light emitted varies with the amount of minerals present

more minerals equals more light.

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Advantages of the Carivis SystemThe Carivis caries assessment system marks a new

approach in preventive dentistry. Its innovative design offers:

Non-invasive, one-step methodCaries activity assessment is possible with a single

visit to the dentistExtreme sensitivity and information on the extent of

demineralisationAccess to all dental surfaces, including contacting

surfaces of teeth and around restorationsEase of useSpeed; signal collection requires less than 10 seconds

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conclusion

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References Cariology , 3rd Ed. - Earnest NewbrunPrinciples & practice of pedodontics – Arathi RaoDentistry for the child & adolescent – McDonaldTextbook of Pedodontics- Shobha Tandon Textbook of Pediatric dentistry- S.G.Damle Essentials of Preventive and community Dentistry- Soben

PeterChair side simple caries activity test: Ora test- Bhasin S,

JISPPD 2006;24:2A Modified dip slide test for microbiological risk in caries

assessment.B Thaweboon,srosori thaweboon etal,Southeast Asian J Trop Med Public health;2006 37:2:400-04

Salivary Glucosyltransferase B as a Possible Marker for Caries Activity-A.M. Vacca Smith. Caries Res. 2007 November; 41(6): 445–450

Using a Caries Activity Test to Predict Caries Risk in Early Childhood. Michiko Nishimura, JADA

Oratest: A Simple Chairside Aid for Caries Risk Assessment -Arora Ruchia, Lahiri. Prathik. Kb, Masih Updes. Int. j of dental clinics 2009:1(1): 26-30

The sensitivity and specificity of a colorimetric microbiological caries activity test (Cariostat) in preschool children. Pediatric Dentistry: July/Aug 1994 - Volume1 6, 4

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