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Tests for prediction and Activity of dental caries

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Presentation on theme: "Tests for prediction and Activity of dental caries"— Presentation transcript:


2 Tests for prediction and Activity of dental caries
Presented by : Deepti Awasthi

3 CONTENTS Introduction Definition Objectives Uses for Clinician
Ideal requisites of caries activity test Tests Conclusion References


5 DEFINITIONS Caries activity Caries susceptibility
Caries activity tests

6 Objectives Identify high risk group and individual
Determine need for preventive measures To 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.

7 Uses for Clinician Determine need for caries control measure
Indicator of patient co-operation Aid in timing of recall appointments Guide to insertion of expensive restorations Determine the prognosis Precautionary signal to the orthodontist in placing bands

8 IDEAL REQUISITES Sound theoretical basis
Maximum correlation with clinical status. Accurate with respect to duplication of results. Simple Quick in performance Inexpensive , feasible Validity Reliability Sensitivity Specificity

9 Various caries activity tests

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

11 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

12 0.4 ml of each sample is spread on the surface of an agar plate
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.

13 Interpretation of LB colony count test
No. of organism CFU/ml Symbolic designation Degree of caries activity + Little or No Slight ++ 1,000– 5000 Moderate +++ ,000 Marked ++++ > 10,000

14 Disadvantages Quick and easy but results are available in days.
Counting colony tedious complex instrument, trained personnel required Not completely exclude the growth of other relatively aciduric organisms Inaccurate for predicting the onset of caries

15 2. Colorimetric SNYDER TEST
SNYDER in 1951 Principle Test measures the ability of salivary microorganisms to form organic acid from a carbohydrate medium 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

16 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.

17 . The media contains : Bactopeptone Dextrose Sodium chloride Agar
Bromocresol green The rate of colour change from green to yellow is indicative of the degree of caries activity. .


19 Advantages : relatively simple Moderate cost Disadvantages : Time consuming Sometimes color change is not very clear Limited predictive value

20 3. THE SWAB TEST GRAINGER et al in 1965. Principle
same as Synder test. Cariology , 3rd Ed. - Earnest Newbrun

21 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.

22 Interpretation : pH 4.1 and < 4.1 = Marked caries pH 4.2 to = Active pH 4.5 to 4.6 = Slightly active pH 4.6 and over = Caries inactive

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

24 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

Non – Conducive (1) Orchid minutes Slightly Conducive (2) Red minutes Moderately Conducive (3) Red Immediately Highly Conducive (4) Pink/white Immediately Extremely Conducive (5)

26 Advantages No incubation Quick results Disadvantages Results vary with time after food intake & after brushing

27 5.ALBAN TEST Simple 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

28 following materials are required:
Synder test agar A small scale to measure 60 grams. A 2 litter Pyrex glass to melt the medium. A funnel to dispense the medium into test tubes. mm test tubes with screw caps

29 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

30 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.

31 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 = ‘+++’ 5. Total colour changes to yellow = ‘++++’

32 Advantages: Simplicity, Low cost, Diagnostic value when negative results are obtained. Motivational value Disadvantages: More armamentarium Subjective evaluation

Action Measures the no. of mls of acid required to lower the pH from 7 to 6. Equipment pH meter 0.05N lactic acid Paraffin Sterile glass jars containing small amount of oil. Cariology , 3rd Ed. - Earnest Newbrun

34 Procedure 10ml of saliva collected under oil 1hr after eating 5ml is taken into a beaker pH of saliva is adjusted to 7.0 Lactic 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

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

36 The samples of organisms is obtained by the use of tongue blades
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

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

38 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

39 8.Dip slide method Dentocult Larmas ,1975 S.Mutans levels in saliva
Procedure Saliva is collected and poured over the agar coated slide & allowed to dry Bacitracin disks are placed in the middle Co2 tablet is inserted in the tube & then incubated for 48 hrs.

40 Colony density (small blue colonies) compared with model chart
negligible <105 > 106

41 9.Plaque / tooth pick method
Action Simple screening of diluted plaque sample Procedure Plaque 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 hrs Cariology , 3rd Ed. - Earnest Newbrun

42 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 macroscopically SCORE 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) wS. mutans adherence method S. mutans dip-slide methods S. mutans replicate technique See for all three -newbrun 42

43 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

44 Advantages Correlation reported is good Disadvantages Complex equipment Expensive, trained personnel.

45 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

46 12. CARIOSTAT TEST Tsutomu Shimono 1974
This test has been reported to significantly correlate with counts of S.mutans in children uses 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

47 Interpretation of Cariostat test
Score pH Color Caries Activity 7 Blue Caries inactive 1 5.5 Green Slight caries 2 4.5 Yellow - Green Moderate caries 3 4.0 Yellow Marked caries

48 13.Oratest Rosenberg et al. in 1989 Principle
The rate of oxygen depletion by micro organisms in expectorated milk samples

49 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

50 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 caries Results can provide dentist to command patient to reinforce motivation ,plaque control and behaviour

51 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.

52 14. Salivary glucosyltransferase b
Gtfs 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-

53 2 ml of saliva was collected
saliva 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

54 15. CariScreen Caries Susceptibility Test
is done in one minute at chairside ATP 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 risk The 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


56 16. Carivis system 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.

57 Advantages of the Carivis System
The Carivis caries assessment system marks a new approach in preventive dentistry. Its innovative design offers: Non-invasive, one-step method Caries activity assessment is possible with a single visit to the dentist Extreme sensitivity and information on the extent of demineralisation Access to all dental surfaces, including contacting surfaces of teeth and around restorations Ease of use Speed; signal collection requires less than 10 seconds


59 conclusion

60 References Cariology , 3rd Ed. - Earnest Newbrun
Principles & practice of pedodontics – Arathi Rao Dentistry for the child & adolescent – McDonald Textbook of Pedodontics- Shobha Tandon Textbook of Pediatric dentistry- S.G.Damle Essentials of Preventive and community Dentistry- Soben Peter Chair side simple caries activity test: Ora test- Bhasin S, JISPPD 2006;24:2 A Modified dip slide test for microbiological risk in caries assessment.B Thaweboon,srosori thaweboon etal,Southeast Asian J Trop Med Public health; :2:400-04 Salivary Glucosyltransferase B as a Possible Marker for Caries Activity- A.M. Vacca Smith. Caries Res 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 Volume1 6, 4


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