CARIES DIAGNOSIS & VACCINE

2. DEPARTMENT OF ORAL PATHOLOGY
Presented by,
Dr.D.Venkatesh kumar
1st yr pg
Caries diagnosis & Caries vaccine

3. CONTENTS
 INTRODUCTION
 DEFINTION
 IDEAL REQUIREMENTS
 HISTORY
 METHODS OF DIAGNOSING CARIES
a) TRADTIONAL METHODS
b) ADVANCED DIAGNOSTIC TESTS
c) RECENT ADVANCES
 CONCLUSION
 REFERENCES

4. INTRODUCTION
Dental caries - multi factorial disease of the calcified
tissues of the teeth, characterized by demineralization
of the inorganic portion and destruction of the organic
substances of the tooth.
progressive bacterial damage to teeth.
one of the most common diseases - 95% of population
& still a major cause of tooth loss.

5. DIAGNOSIS
Diagnosis is the art or act of identifying a disease from its
signs and symptoms.
The word diagnosis (plural, diagnoses) -Greek ‘‘dia’’
meaning ‘‘thorough’’ and ‘‘gnosis’’ meaning
‘‘knowledge’’.

6. IDEAL REQUIREMENTS
1. Accurate.
2. Sensitive.
3. Specific.
4. Reproducible.
5. Reliable.
6. Not transfer S. Mutants from affected area to
unaffected area
7. Cost effective

7. HISTORY OF PATIENT
History Factors Risk Increasing (Observational)
 Age Childhood, Adolescence
Senescence
 Gender Women at slightly greater
risk
 Fluoride exposure No fluoride in public water
supply
 Diet Sugar containing foods, sticky foods
 Smoking Risk increases
 General Health GIT disorders & H/O Radiation
 Medication reduce salivary flow

8. METHODS FOR DIAGNOSING CARIES
 VISUAL EXAMINATION.
 TACTILE EVIDENCE OF CARIES-PROBING
 TOOTH SEPARATION.
 DENTAL FLOSS.
 RADIOGRAPHIC
CONVENTIONAL
XERORADIOGRAPHY
MODIFIED RADIOGRAPHIC TECHNIQUES
IOPA
BITEWING
DIGITAL
ENHANCEMENT
COMPUTER
IMAGE
ANALYSIS
SUBSTRACTION
RADIOGRAPHY
CBCT

9.  INTRAORAL CAMERA
 ELECTRIC RESISTANCE ( CONDUCTANCE)
 OPTICAL DETECTION
 DYES
FIBER OPTIC
TRANSILLUMINATION
DIGITAL IMAGING FIBER
OPTIC TRANSILLUMINATION
QUANTITATIVE LASER
FLUORESCENE
DIAGNODENT

10. RECENT ADVANCES
TERAHERTZ IMAGING
OPTICAL COHERENCE TOMOGRAPHY
CARIE SCAN
ULTRASONIC IMAGING

11. TRADITIONAL METHODS
VISUAL EXAMINATION :
Encompasses – criteria - detection of white spot,
discoloration and frank cavitation.
 Examiner detects caries - change in translucency of
enamel.
 Clean, dry and well-illuminated field.
ICDAS – INTERNATIONAL CARIES DETECTION AND ASSESSSMENT
SYSTEM - improved version of visual methods.

13. DISADVANTAGES
Reliability Caries depth
Discoloration
– pits –
healthy tooth
– mistaken –
caries

14. TACTILE EVIDENCE OF CARIES:
EXPLORER
 Determining roughness or softness of tooth surface with a sharp
explorer.
 Both penetration & resistance to removal of an explorer tip -
evidence of demineralization
 The explorer can be of different varieties such as:
a) Right angle probe
b) Back action probe
c) Shepherds crook
d) Cow horn with curved ends

15. PROBING - CRITICIZED & QUESTIONED
 May transmit cariogenic bacteria.
 May produce irreversible traumatic defects in potentially re-
mineralizable enamel.
 Mechanical binding of an explorer tip in a fissure - other causes
like:
• Shape of fissure.
• Sharpness of explorer
• Force of application
• Path of explorer placement

16. TOOTH SEPARATION
 Electively and temporarily separating approximal surfaces - examine them
 Adjunct to C & R examination
 It has good potential in validating other diagnostic methods of detecting
approximal lesions.
 The method requires a second brief visit after a period of 3-7 days.
LIMITATIONS:
 Requires second visit
 Discomfort to patient.

17. DENTAL FLOSS
Pickard(1961) - use of dental floss for detection of caries.
If its shreads one can suspect
a proximal cavity.
Disadvantage- overhanging restorations- proximal side –same
features.

18. RADIOGRAPHIC TECHNIQUES
 2 dimensional picture of 3 dimensional object.
 Net mineral loss must exceed at least 40-60% - radio graphically visible.
IOPA-
 primarily used for detecting changes around roots & in b/n teeth
 Paralleling technique is superior to bisecting technique
 Visualization of approx 3 teeth
CONVENTIONAL RADIOGRAPHS

19. BITEWING
To detect INCIPIENT CARIES AT CONTACT POINTS
8 teeth in one radiograph can be visualized
Regarding…
incipient carious lesions,
cervical margins of restoration ,
alveolar crest height ,
pulp chambers.

20. PROBLEMS ENCOUNTER WITH RADIOGRAPHIC METHODS
1. Overlapping of proximal contacts.
2. Gagging sensation
3. False diagnosis due to overestimation- increase lesion depth -change -
angulations.
4. Radiolucency cannot be judged - because of caries /resorption
5. Superficial demineralization - buccal & lingual surfaces - imaged - approximal
caries.
6. Cervical burnout may mimic cervical caries.

21. RADIOGRAPHIC INTERPRETATION OF OCCLUSAL CARIES LIMITATIONS
1.Caries in enamel - difficult -superimposition of enamel
over the fissures.
2. Lesions involving buccal grooves of molars are
superimposed over the occlusal area - simulate occlusal
lesions.
3. A thin radiolucency appears at the DEJ in occlusal caries,
which is missed -considering - normal difference of
radiolucency in enamel & dentin.

22. PROBLEMS IN DIAGNOSIS OF SECONDARY CARIES
Lesions - occlusal surface, b/n restoration & tooth
cannot be visualized until - advanced stage.
It is often difficult to differentiate between secondary
caries & caries which have been left during restoration
(residual caries).

23. XERORADIOGRAPHY
 It is complete dry non chemical process
 Image is recorded on aluminium plate coated -layer of selenium particles.
 Selenium particles - uniform electrostatic charge & stored - conditioner.
 When X-rays are passed – film selective discharge –Se particles.
POSITIVE IMAGE LATENT IMAGEDEVELOPMENT
C.F.Carlson
1937

24. XERORADIOGRAPHY
• Later the procedure, Al plate - cleaned and used again .
• Xeroradiography is twice as sensitive as conventional films
and a phenomenon of 'Edge Enhancement' is possible with
this technique.
• No dark room for developing.
• No special light source for view .

25. XERORADIOGRAPHY
ADVANTAGES
• Edge enhancement
• Less radiation
• Economical
DISADVANTAGES
• Electric charge-film – discomfort to patient
• Development- 15 min

26. REASON FOR ADVANCES
Advantages of early caries detection:
Opportunity to monitor caries progression by remineralization.
Creates an opportunity for a preventive - outdated “Drill and Fill”
approach.
New diagnostic modalities allow early lesions of caries to be quantified.

27. INTRA ORAL CAMERA
Camera placed inside oral cavity to
display
Intra oral images on a computer
• Improved visual access
• Improved lightening
• Improved magnification
• Demonstrate pt needs for
treatment

28. MODIFIED RADIOGRAPHIC TECHNIQUES
 R/F recorded – digital image receptors & enhanced – computer
processing.
 A digital image - image formed & represented by a spatially
distributed set of discrete sensors & PIXELS.
 Receptors-highly sensitive sensors - less radiation exposure than
film
 It is the Image that has been recorded with non-film receptor.
DIGITAL ENHANCEMENT

29. Two types of non film receptors for recording digital
images :
Digital image receptor (DIR)-collects x- rays
directly(DDI) Direct digital imaging
Scanning device -forming digital images- radiograph (IDI)
Indirect digital imaging

30. DIRECT RECEPTORS
Direct receptors communicate - computer -electronic
cable-transfers data -radiofrequency transmitter.
charged couple device (CCD)-connected to computer.
CCD is a semiconductor- metal oxides( silicon ) that is
coated with x-ray sensitive phosphorous.
CCD is sensitive both to X-rays and visible light.

31. displayed for viewing.
stored in the computer- image processing
detected - CCD.
light photons are produced,
x-rays strike the screen
The intraoral DIR is placed in the mouth

32. INDIRECT RECEPTORS
When x-rays interact - phosphor,
latent image is formed & stored
plates - transferred & inserted -
scanning device
digitized, using laser light scanning.
Digitized images - stored-
displayed- computer
Photostimulable phosphor plates (PSP)

33. ADVANTAGES
• Darkroom is not required
• Instant image is viewed
• The quality of image is consistent
• Elimination of the hazards of film development
• Radiation dose is decreased
• Capability for teletransmission.
DISADVANTAGES
• High cost of system
• life expectancy - not fixed
• Detection of occlusal caries: performed almost equally well.
• No value in detection of initial enamel lesions / proximal dentinal lesions

34.  Made it possible to use automated
procedures-overcome-
shortcomings-human eye - caries
detection.
 Softwares - developed for
automated interpretation of digital
radiographs.
 This technique is based on the
“EXPERT SYSTEM”
programme gives us the diagnosis.
programme compares the patient’s
data with the basic knowledge of the
pathology.
clinician enters the patient’s data
COMPUTER IMAGE ANALYSIS

35. ADVANTAGES
• provide sensitive and objective observation- small lesions
• possible to monitor the lesion
• Quantification of small lesions - possible
DISADVANTAGES
• Always need-standardization of exposure geometry
• Sensitivity is higher but specificity is lesser
• Time consuming and less economical.

36. SUBTRACTION RADIOGRAPHY
 PRINCIPLE: Optimally, all unchanged anatomical background structures
will cancel and unchanged areas will be displayed in a neutral grey shade in
the subtraction image.
Areas with mineral loss - darker shades of grey
 Structured noise is reduced - to increase the detectability of
changes in the radiographic pattern.

37. Structured noises are the images, which are not of diagnostic value and
interfere in routine interpretation of radiographs.
 Disadvantages:
 Inability to produce correct projection geometry
 Improper density and contrast

38. CONE BEAM CT
Chief limitation - conventional intra-oral radiographs -
(2D) image- structure (3D).
CBCT - three dimensional imaging(3D) system
This method - constructs radiographic slices, cross-
section through teeth

39. Slices - viewed for radiolucencies
Specifically useful for the detection of RECURRENT
CARIES.
CBCT - utilizes least amount of radiation- cost
effective for patients.
Radiation dose = quarter panoramic image / five dental
x rays- high-speed film.

40. OPTICAL DETECTION
Principle: carious lesion - low index- light transmission, -
appears- dark shadow.
Evolved due -growing concerns about ionizing radiations
Vaarkamp et al (1997): early enamel lesions can be detected.
Fiberoptic - halogen lamp + rheostat ------> light of variable
intensity
FIBRE OPTIC TRANSILLUMINATION

41. For examination, tip - probe - Embrasure immediately
beneath the contact point
 Shadow - beneath -marginal ridge may be evident -
break - integrity -enamel
This can detect Enamel– crazing, cracks in tooth.

42. ADVANTAGES
• No hazards of radiations
• Simple and comfortable- patients
• Lesions, which cannot be diagnosed R/F
• Not time consuming.
DISADVANTAGES
• Permanent records - difficult to maintain
• Difficult to locate the probe in certain areas
• Only useful for approximal and occlusal lesions
• not quantitative – NOT useful - caries monitor over time
• High level of inter and intra examiner variability

43. DIGITAL IMAGING FIBER OPTIC TRANSILLUMINATION
DIFOTI -overcome shortcomings of FOTI - FOTI - digital
CCD camera.
FOTI - proximal and occlusal caries
 DIFOTI - Both incipient & frank caries – all tooth
surfaces
It was developed by Schneiderman et al 1997

44. MECHANISM:
Light propagates -optical fiber - tooth .
During Transillumination, - area of demineralization scatter
light and incipient lesions appear darker - image.
Image - digital electronic CCD camera - eliminate
inter/intra examiner variability.
 Image - analyzed -computer.
It can not only detect the early lesions but also monitor -
progress of lesion.

46. ADVANTAGES
• Detect fractures, integrity - restorations
• Instant images – obtained
• Non invasive
• detects early & hidden caries
• No film, film processing
LIMITATIONS
• It cannot indicate - depth of lesion penetration.
• Cannot be used to detect caries in subgingival area.
• Cannot image -tooth completely covered by restoration

47. QUANTITATIVE LASER OR LIGHT – INDUCED FLUORESCENCE
Quantitative assessment of dental caries.
1st investigation-Bejelkhagen & Sundstrom (1981).
In QLF method, tooth - irradiating -visible light - blue green
region.

48. Tooth- fluorescent green - Demineralized - as dark spots.
Fluorescent filtered images - CCD video camera.
Data - collected, stored and analyzed by custom-made
software.
Clinical applications:
 clinical trials, patient education, and preventive clinical
practice.
Monitor demineralization of teeth.
early secondary caries beneath restorations

49. Advantages:
Limitations:
• Cannot discriminate b/n enamel lesions & dentin
• Cannot differentiate b/n decay, hypoplasia & unusual anatomical features
• Incipient lesions - detected.
• Sometimes red fluorescence-porphyrins - indicates presence of
dental biofilm, or high caries activity
• Quantification – enamel lesions -depth -400 µm

50. LASER FLUORESCENCE METHOD
Measures the fluorescence - tooth that is induced after light
irradiation to discriminate between carious and sound enamel.
 DIAGNODENT:
 It is a portable diode laser device.
 It operates- infra red light from a diode laser
 light- transmitted - descendent optic fiber to a hand-held probe-
surface of tooth

51.  Emitted fluorescence measured- photo-diode detector.
 control unit displays digital representation - wavelength detected
 The signal is finally processed & display an integer b/n 0 and 99 and
also acoustically.

52. If the reading is 21-100 - definite area of decay - require
operative intervention.
5-25: initial lesions
25-35: early dentinal caries
> 35: advanced dentinal caries
Clinical applications:
The device performs best on smooth surfaces and in
occlusal pits and fissures

53. ADVANTAGES
• High reproducibility
• High sensitivity & specificity
• May detect lesions -not apparent on R/F
• Easy to use
LIMITATIONS
• Can detect enamel demineralization but cannot differentiate b/n decay, hypoplasia, or
unusual anatomical form
• Diode laser –cannot reach deep dentinal areas- differentiate b/n superficial & deep
dentinal caries

54. DIAGNODENT PEN
Improved version -diagnodent.
 It has improved tips (less prone to breakage) & new
small tip for detection of interproximal caries.
Better digital display and audible caries indicator are
also included .

55. DYE PENETRATION METHOD:
In caries diagnosis, qualitative examination- prior
requirement.
observation of coloured dye signifies presence of caries.
Dyes should fulfill the following criteria :
Dyes should be
absolutely safe for
intra oral use.
Dyes should be
specific
Dyes -easily
removed & not
lead to permanent
staining.

56. DYES- CARIOUS ENAMEL
'Procion' dyes stain enamel - irreversible and acts as
a fixative.
'Calcein' dye makes a complex with calcium- bound to
the lesion.
'Brilliant blue‘- enhance the diagnostic quality of FOTI

57. DYES- CARIOUS DENTIN
carious dentin - two layers- outer layer-soft -cannot be
remineralized & inner- hard & can be remineralized.
0.3% Basic Fuschin in propylene glycol – demineralized
dentin which the collagen is stained- inner one remains
unstained– outer dentin removed clinically.
The staining by the dye is the result of denaturation of
collagen.

58. Basic Fuschin dye – carcinogenic- replaced- acid red
& methylene blue.
Methylene blue is also slightly toxic so acid red is
preferred.
Acid red is specific and more reliable

59. MODIFIED DYE PENETRATION METHOD
'The Iodine penetration method' -enamel porosity -
incipient caries- Bakhos et al. (1977).
 Potassium iodide - specific period of time -
well-defined area of enamel - excess is removed.
The iodine, which remains in the micropores, is
estimated and that indicates the permeability of
enamel.

60. TERAHERTZ IMAGING
Terahertz pulse imaging (TPI) - new imaging technique
Terahertz freq 1012HZ / wavelength of 30µm.
 Although, the TPI - new technique - imaging caries -a
hope in future it could indicate caries in all areas of teeth
For an image to be obtained by terahertz irradiation the
object is placed in the path of the terahertz beam.
RECENT ADVANCES

61. Also possible - record terahertz images - CCD detector .
Longitudinal sections through 3 teeth have demonstrated
increased terahertz absorption by early occlusal caries
Work in progress to image intact teeth with early carious
lesions.

62. Advantages:
Disadvantages:
• TPI system uses only micro-watts - non-ionizing
• more safer than those employing X-rays
• Adverse thermal effects are unlike
• Relatively expensive
• Needs more researches to make it possible to be used in
OC

63. OPTICAL COHERENCE TOMOGRAPHY (OCT)
Method of measuring transparent and semitransparent
structures
Based on interference of light- & measures -light
scattering
OCT can be defined as optical infer metric technique to
create cross sectional images of scattering media.

64. OPTICAL COHERENCE TOMOGRAPHY (OCT)
 OCT provides high resolution - imaging of incipient caries.
With OCT, early lesions can be readily identified as regions of
high light backscattering with depth into the enamel as
compared to healthy sound enamel.

65. Clinical applications:
• Imaging -
interproximal &
occlusal caries
• Early root
caries
Advantages
• quantitatively
monitor- mineral
changes - lesion.
• Can determine
depth of the lesion.
Disadvantages
• Regions of high
light backscattering
- not related to
caries development
can lead to false
positive results.

66. CARIESCAN
Cariescan offerrs earliest possible detection of caries.
Unique device provides accurate & repeatable data to
monitor caries over time.
Mechanism:
It utilizes AC impedance spectroscopy (ACIST).
The impedance- healthy tooth -very high due to relatively
low ionic conduction.

67. As a tooth demineralizes – increase- larger pores.
As lesion progresses, pores -connect & tooth becomes a mix
of high & low conductive parts -impedance decreases.
As the decay progresses, dentin involved- impedance falls
further.
 As a result the sensitivity and specificity of the ACIST system
in distinguishing these different stages is very high .

68.  0-100 scale
 0-50 = low probability of caries
 51-90 = medium probability of caries
 91-100 = high probability of caries
 Used for the detection of EARLY AND HIDDEN LESIONS
 92.5% accurate in detecting both sound and carious teeth, minimizing
false positive or false negative results.

69. ADVANTAGES
• Highest proven accuracy of all caries detection methods
• No ionizing radiation risk
• Easy to record and compare progress
 CONTRAINDICATIONS :
 patients with cardiac pacemakers fitted.
 DISADVANTAGES: It cannot be used to assess:
Secondary caries
Integrity of a restoration
Dental root caries
 It should not be used when tooth surfaces - plaque and or other debris.

70. ULTRASONIC IMAGING
Introduced - detecting early carious lesions - smooth
surfaces.
PRINCIPLE:
The demineralization of natural enamel is assessed by
ultrasound pulse echo technique
It is observed -definite correlation b/n mineral content of
lesion & relative echo amplitude changes.

71.  Ultrasonic probe - longitudinal waves - surface - tooth & also serves the
function of receiving the Waves.
 Application: To find lesions on smooth surfaces & detecting RECURRENT
CARIES
Sound wave with frequency 1.6 to 10 MHz
 Initial white spot lesions ─ no or weak echo
 Cavitated lesions ─ echo with high amplitude
To be continued………