This is presentation on caries risk assessment prepared by an undergraduate student.

1. CARIES RISK
ASSESSMENT
PRESENTED BY: GUIDED BY:
USHU SHRESTHA Dr. Sumita Upadhyay
ROLL NO. 43 Dr. Rasna Shrestha

2. CONTENTS
 Introduction
 Components of caries risk assessment
 Various caries activity tests
 Cariogram
 Caries risk assessment tool
 Conclusion
 References
 MCQs

3. INTRODUCTION
Caries Risk Assesssment can be defined as a procedure to predict future
caries development before the clinical onset of disease.
Assessment of risk forms the key element in preventing any diseases and it
guides the practitioner to institute appropriate preventive strategies.

4. Caries activity Test:
It is defined as tests that estimate the actual state of disease activity {progression
or regression}.
Risk Factor:
It is defined as factor which plays an essential role in the etiology and
occurrence of the disease, like the lifestyle and biochemical determinants to which
the tooth is directly exposed and which contribute to the development or
progression of the lesion{plaque, saliva, diet, etc}.
Risk Indicator;
It is a factor or circumstance that is indirectly associated with the disease like
socioeconomic factors and epidemiological factors.

5. Caries Risk Assessment Helps To ?
•Determine need and extent of personalized preventive measures
• Motivation of patient
• Monitor the effectiveness of programs
• Criteria for the success of therapeutic measures
• To identify high-risk groups
• Determine need for caries control measures
• Aid in recall appointments
• Aid in selection of patient for caries study

6. COMPONENTS OF CARIES ACTIVITY TEST
These were summarized by Snyder as:
• Should have sound theoretical basis
• Simple
• Easy to perform
• Inexpensive
• Time for test and result should be
small
• Should be adaptable for chair-side
•Results should be accurate and reproducible
• Test should have maximal correlation with
clinical status
•Should have good validity, reliability &
feasibility.

7. Caries Activity Tests:
Lactobacillus Colony Count Test
S. mutans Level in Saliva
Colorimetric Synder Test
The Swab Test
Salivary Reductase Test
Dip Slide Method For S.mutans Count
Salivary Buffer Capacity Test
Alban Test
S. Mutans Screening Test
Fosdick Calcium Disssolution Test
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8. This is subtitle number One.
Lactobacillus Colony Count Test
 Introduced by Hadley in 1933
● Counts no. of aciduric and acidogenic
bacteria in saliva by counting number of
colonies appearing on LBS agar{Rogosa}.
● The total number of colonies on this
medium reflects the proportion of the
aciduric flora in the saliva.
1 2 3 4 5 6 8
7 9 10

9. Procedure:
• Immediately after arising, the patient chews a small piece of paraffin.
• The saliva that accumulates in the following 3-minute period is collected in a sterile
container, and shaken well.
• The saliva sample is diluted to 1:10 dilution by sterile saline solution, and then 1:100
dilutions.
• 0.4 ml of each dilution is spread on the surface of an agar plate containing 20 ml of cooled
liquefied agar .
• Incubation at 37°C for 3-4 days.
• The number of lactobacilli {whitish dots} per mm saliva is calculated by multiplying the
number of colonies on the plate by the dilution factor.

10. INTERPRETATION:

11. ADVANTAGES:
• Useful for monitoring the effectiveness of restorative dentistry.
• Simple to carry out.
• Useful as a screening test for caries activity in large groups.

12. DISADVANTAGES
• Inaccurate for predicting the onset of caries.
• Does not completely exclude the growth of other aciduric organisms.
• Counts involving single individuals are not as reliable.
• Takes few minutes to do the test, but the results take several days.
• Counting is a tedious procedure.

13. Streptococcus Mutans Level in Saliva
 Principle involved:
 - Measures the number of S.mutans CFU per unit
volume of saliva and plaque samples from discrete
sites, such as occlusal fissures and proximal areas.
 Incubation is done on Mitis Salivarius Agar(MSA),
selective streptococcal medium with addition of high
concentration of sucrose(20%), and 0.2 U Bacitracin
(MSB), suppress the growth of most non-S.mutans
colonies
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7 9 10

14. Streptococcus Mutans Level in Saliva
 Procedure
 • Sample collection by the use of tongue blades (wooden spatulas).
 • Tongue blades then pressed against MSB Agar.
 • Incubation at 37°C for 48 hours in 95% at 5 % CO2 gas mixture.
 Interpretation:
 Levels of Streptococcus mutans > 105/ml of saliva is unacceptable.
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7 9 10

15. Streptococcus Mutans Level in Saliva
 Advantage:
 -Useful in caries management as S.mutans are main causative agents.
 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 site only.
1 2 3 4 5 6 8
7 9 10

16. Principle involved:
-Measures the ability of salivary microorganisms to form organic acid from a
carbohydrate medium.
-The medium contains an indicator dye “Bromocresol green”, changes colour
from green to yellow when pH changes from 5.4 to 3.8.
-Indirectly measures the number of both aciduric and acidogenic organisms in
saliva.
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7 9 10
COLORIMETRIC SYNDER TEST

17. 1 2 3 4 5 6 8
7 9 10
Procedure:
• 0.2ml stimulated saliva collected by chewing paraffin before
breakfast is thoroughly mixed with 10 ml melted agar containing
medium in a test tube (cooled to 50°C).
• Allowed to solidify and then incubated at 37°C.
• Amount of acid produced by acidogenic organisms is detected by
changes in pH indicator, and is compared to an un-inoculated
control tube after 24, 48, and 72 hours.
• The rate of colour change from green to yellow is indicative of the
degree of caries activity.

18. 1 2 3 4 5 6 8
7 9 10
Interpretation
If the color is yellow- If the color is green-

19. 1 2 3 4 5 6 8
7 9 10
Advantages
• Relatively simple to carry out.
• Tests are of value in assessing the cariogenic challenge.
• Only one tube and no serial dilutions are required.
Disadvantages
• Time consuming.
• Sometimes the colour changes are not so clear.

20. The Swab Test
1 2 3 4 5 6 8
7 9 10
- Grainger et al developed this test in 1965.
Principle involved: Same as Snyder’s test.
Procedure:
• The oral flora is sampled by swabbing the buccal surfaces of teeth
with a cotton applicator, which is subsequently incubated in the
medium.
• The change in the pH following 48 hour incubation is read on a pH
meter or colour change is read by the use of a colour comparator.

21. 1 2 3 4 5 6 8
7 9 10
Interpretation:
Advantage:
Useful in predicting caries increments or changes, particularly in children,
as no collection of saliva is required.

22. 1 2 3 4 5 6 8
7 9 10
Principle involved: Measures the activity of the
reductase enzyme present in salivary bacteria,
using a dye Diazo-resorcinol.
Procedure
• Saliva is collected in a plastic container.
• The sample is then mixed with the dye.
• The caries conduciveness is measured by color
change, seen after 15 minutes. (A kit is
available under the trade name Treatex.)
Salivary Reductase Test (Susceptibility Test)

23. 1 2 3 4 5 6 8
7 9 10
Interpretation: The evaluation is based on the color change
Advantages:
Quick results, as no incubation period is required.
Disadvantage:
Test results vary with time after food intake and after brushing.

24. Dip-Slide (Dentocult-Sm) Method for S.Mutans Count
 It estimates Streptococcus mutans levels in saliva.
 Procedure
 • Undiluted paraffin- stimulated saliva is poured on a special plastic slide,
coated with MSA(Mitis Salivarius Agar) containing 20% sucrose. The agar
surface is thoroughly moistened and excess saliva is allowed to drain off.
 • Two discs containing 5 mg of bacitracin are placed on the agar 20 mm apart.
 • The slide is tightly screwed into a cover tube and incubated at 37°c for 48
hours in a sealed candle jar.
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7 9 10

25.  Interpretation
 Score 1 =Low: The colonies are discrete and could be readily
counted at 15X magnification with the total count of CFU
inside the inhibitions zones less than 200.
 Score 2 =Medium: The colonies are discrete and the number in
the zone of inhibition is more than 200 at 32X magnification.
 Score 3 = High: The colonies are tiny and almost completely or
totally cover the inhibition zone with the number of colonies
uncontrollable even with 32X magnification.
6

26.  Principle involved: Buffer capacity can be quantitated using either a pH meter
or colour indicators.
 This test measures the number of milliliters of acid required to lower the pH of
saliva through an arbitrary pH interval (6 to 7) or the amount of acid or base
necessary to bring color indicators to their end point.
 Equipments:
 pH indicator
 Titration equipment
0.05 N lactic acid
0.05 N base, paraffin
Sterile glass jars containing a small amount of oil.
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7 9 10
Salivary Buffer Capacity Test

27.  Procedure
 • 10 ml of stimulated saliva is collected under oil at least I hour after
eating.
 • 5 ml of this is measured into a beaker.
 • After correcting the pH meter to room temperature, the pH of saliva is
adjusted to 7.0 by addition of lactic acid or base.
 • Lactic acid is then added to the sample until a pH of 6.0 is reached.
 • The number of ml of lactic acid needed to reduce pH from 7.0 to 6.0 is
a measure of buffer capacity. (can be converted to milliequivalents per
liter)
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7 9 10

28.  Interpretation:
 “Inverse relationship between buffering capacity of saliva and caries
activity”.
 The saliva of individuals with considerable no. of carious lesions
frequently have a lower buffering capacity.
 Advantage: Simple to carry out.
 Disadvantage: Doesn’t correlate adequately with caries activity
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7 9 10

29. Alban Test
 It is a simplified substitute for the Snyder test.
 Principle involved: Same as Snyder test.
 Procedure: To prepare the Alban test medium:
 Materials required
 • Snyder test agar
 • A small scale, to measure 60 grams.
 • A 2 liter 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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7 9 10

30.  Steps:
• 2 tubes of Alban medium are taken from the refrigerator.
 • The patient is asked to expectorate a small amount of saliva directly into the
tubes.
 • The tubes are labeled and incubated at 98.6°F (37°C) for up to 4 days.
 • The tubes are observed daily 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.
 • The daily results collected for a 4 day period recorded on the patient chart.
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7 9 10

31. 1 2 3 4 5 6 8
7 9 10
Interpretation
Inferences
• Readings negative for the entire incubation period are labeled- Negative.
• All other readings are labelled- Positive (+, + +, + + + or + + + +)
• Slower change or less colour change (compared to previous test) is labelled- Improved.
• Faster or more pronounced colour change (compared to previous test) is labelled- Worse.
• When consecutive readings are nearly identical, labelled as- No change.

32. a. Plaque/Tooth pick method:
 Simple screening of diluted plaque sample streaked on a selective culture media.
“Semi quantitative screening of dental plaque for S.mutans”
 Procedure:
 • Plaque samples are collected from the gingival thirds of buccal tooth surfaces one from each
quadrant and placed in Ringer's solution.
 • The sample is shaken until homogenized.
 • The plaque suspension is stretched across MSA plates.
 • Aerobic incubation at 37°C for 72 hours.
 • Cultures are examined and total colonies in 10 fields are recorded.
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7 9 10
Streptococcus Mutans Screening Test:

33.  b. Saliva / Tongue Blade Method:
 It estimates the number of S.mutans in paraffin-stimulated saliva when cultured in Mutans
Salivarius Bacitracin (MSB) agar.
 • Suitable for use in the studies involving school children.
 Procedure
 • The subjects chew a piece of paraffin wax for one min to displace plaque microorganisms,
to increase their proportion in saliva.
 • Sterile tongue blades are rotated in the mouth 10 times so that both the sides are
thoroughly inoculated with the subject’s flora.
 • Tongue blades are then pressed into MSB agar.
 • Incubation is done at 37°C.
 • Numbers of colonies are counted.
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7 9 10

34. Fosdick Calcium Dissolution Test
 Principle involved:
 - Measurement of amount of powdered
enamel dissolved in 4 hours by acid
formed, when the patient’s saliva is
mixed with glucose and powdered
enamel.
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7 9 10

35.  Procedure:
 • Saliva is stimulated by having the patient to chew gum or paraffin.
 • 2.5 ml of saliva is collected.
 • One part of this is used to analyze the calcium content.
 • The remaining is taken into a 8 inch sterile test tube, in which 0.1 gm
of powdered enamel is added.
 • Test tube is sealed and shaken for 4 hours at body temperature.
 • Then calcium content is analyzed.
 • When paraffin is used to stimulate saliva, 5% glucose is added.
(Chewing gum contains sugar).
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7 9 10

36.  Interpretation:
 - Amount of calcium increases, as the caries activity increases.
 Advantage:
 - In the limited studies, correlation reported is good.
 Disadvantages
 • Requires complex equipment and trained personnel
 • Expensive.
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7 9 10

37. - Model proposed by Bratthall Douglas
- Computer program showing a graphical picture that illustrates a possible
overall caries risk scenario.
- Patient is examined and data is collected for some factors of direct
relevance for caries including bacterias, diet, susceptibility related factors.
- The various factors/variables are given a score according to the
predetermined scale and entered in the computer program.
CARIOGRAM

39. According to its built in formula, the
program presents a pie diagram where
bacteria appears as a Red Sector.
- Diet as dark blue sector.
- Susceptibility related factor as light blue
sector.
- Some circumstances as a yellow sector.
- Green sector as ‘Chance of avoiding caries’

40. EVALUATION
Dark blue sector ‘Diet’ – diet contents + frequency
Red sector ‘bacteria’ is based – amount of plaque + mutans
streptococci
Light blue sector ‘susceptibility’ - fluoride program + saliva
buffering capacity
Yellow sector ‘circumstances’ – caries experience + related
diseases
Green sector shows an estimation of ‘chances of avoiding caries’

41. Advantages:
- Model is affordable
- User-friendly
- Easy to understand
- Tool for motivating the patient
- Model can also serve as a support for clinical decision
making when selecting preventive strategies for the patient

42. Caries Risk Assessment Tool
 The table is a first step toward incorporating available evidence into
a concise, practical tool to assist both dental and non-dental health
care providers in assessing levels of risk for caries development in
infants, children and adolescents.
 The AAPD intends this to be a dynamic instrument that will be
evaluated and revised periodically as new evidence warrants.

43. AAPD CARIES RISK ASSESSMENT TOOL

44. AAPD CARIES RISK ASSESSMENT TOOL

45. AAPD CARIES RISK ASSESSMENT TOOL

46. AAPD CARIES RISK ASSESSMENT TOOL

47. Users of the AAPD caries-risk assessment tool (CAT) must understand the following caveats:
1. CAT provides a means of classifying dental caries risk at a point in time and, therefore,
should be applied periodically to assess changes in an individual’s risk status.
2. CAT is intended to be used when clinical guidelines call for caries-risk assessment.
Decisions regarding clinical management of caries, however, are left to qualified dentists
(ideally, the dentist responsible for the child’s “dental home”).
3. CAT can be used by both dental and nondental personnel. It does NOT render a diagnosis.
However, clinicians using CAT must be familiar with the clinical presentation of dental
caries and factors related to caries initiation and progression.
4. Since clinicians with various levels of skill working in a variety of settings will use this
instrument, advanced technologies such as radiographic assessment and microbiologic
testing (shaded areas) have been included but are not essential for using this tool.

48. Since dental caries is a highly prevalent disease, control of dental caries is a concern
of all the people.
For developing countries like Nepal, the focus should be on the caries risk and
identifying those individuals at high risk to develop caries.
Preventive measures can then be targeted at this group thereby not only reducing the
economic burden of the restorative care but also eliminating pain & involving the
overall quality of life.
CONCLUSION

49. Marwah N. Textbook Of Pediatric Dentistry, 4th ediition
Tandon S. Textbook of Pedodontics, 2nd edition, Paras Medical Publishers
Peter S. Essentials Of Community Dentistry, 6th edition
https://www.rroij.com/open-access/caries-activity-tests-50-59.php?aid=34518
References

50. 1. The components of caries activity test was given by:
a. Grainger b. Hadley
c. Synder d. Bratthall
2. Bromocresol green is used as an indicator dye in which test?
a. Salivary buffer capacity test b. Colorimetric synder test
c. Fosdick test d. Salivary reductase test
MCQS

51. 3. According to salivary buffer capacity test, buffer capacity and caries
activity are:
a. Directly related b. Inversely related
c. Unrelated d. None
4. ‘The actual chance to avoid new cavities’ is denoted by:
a. Green sector b. Yellow sector
c. Dark blue sector d. Red sector
MCQS

52. 5. Occasional in between meals exposure to foods strongly associated
with caries indicates :
a. High risk b. Low risk
c. Moderate risk d. No risk
MCQS

53. Thank
you