A detailed presentation on the contemporary (presently preferred), conventional and potential modalities of caries diagnosis in the vast and developing world of dentistry. This slide was prepared in conjunction with Dr. Janhavi Rajput & Dr. Ishaan Adhaulia. Hope this presentation brings clarification and light to the detailed topic.

1. Dr. Janhavi Rajput
Dr. Ishaan Adhaulia

2. • INTRODUCTION
•DEFINITION
•BRIEF OVERVIEW – CONVENTIONAL DETECTION METHODS
•CONTEMPORARY METHODS OF CARIES DETECTION
•POTENTIAL CARIES DETECTION METHODS

3. Advanced methods for caries diagnosis can be used as adjuncts
to the conventional visual and tactile examination. Most of the
advanced methods are not easily available, are time consuming
and needs lot of skill to practice. A combination of these newer
techniques with the conventional methods would help us to
give more reliable and accurate results.

4. “The eye’s do not see what the mind doesn’t know”
Diagnosis is to distinguish irregularities and other issues of
concern based upon a patient’s examination and interview. In
Greek “dia” means thoroughly and “gignoska” means to know

5. Its the art or act of distinguishing one disease from another.
Modern management of caries is based on 3 major components
•Prevention
•Control
•Treatment
A diagnostic method should allow for detection of the disease
in the earliest stages and for all pathological changes attributed
to the disease to be determined.

6. •Identifying lesions which do not require restorations
•Identifying lesions requiring restorations.
•Persons at high risk for developing caries
Sensitivity: Ability of test to diagnose disease correctly when disease is
actually present
Specificity: Rule out disease correctly when it is truly absent
Thus diagnosis is done using:
Clinical criteria
Tools
Newer refined diagnostic tools

7. According to WHO the shape & depth of
carious lesion can be scored
D1 : enamel lesion, no cavity
D2 : enamel lesion, cavity
D3 : dentin lesion, cavity
D4 : dentin lesion, cavity to pulp

8. 1)Radiographic Techniques
• Xero-radiography
• Digital imaging
• Digital subtraction radiography
• Tuned aperture computed radiography
2)Visible light
• Fiber optic trans-illumination
• Digital fiber optic trans-illumination
• Quantitative light-induced fluorescence
3)Laser light
• Laser fluorescence measurement (Diognodent)
4)Electric current
• Electric conductance measurement.

9. Visual Examination : Mouth mirror,
probe (explorer), good light.
Conventional method.
•Every tooth is dried and examined
Tactile evidence
• Roughness or softness of the tooth
with explorer.
• Penetration and resistance to removal
with an explorer tip.

10. 0 - No caries or radiolucency after air drying.
1 - White/brown opacity hardly visible on wet surface/distinctly
visible on dry surface
2 - Opacity visibly distinct with out air drying
3 - Localized enamel breakdown in opaque or discolored e
enamel or grayish discoloration from dentin.
4 – Cavitation exposing the dentin

11. •Visual methods
•Detection of white spot, discoloration / frank cavitations
•Without aids, unreliable
•Magnification loupes- Head worn prism loupes (X 4.5) or surgical
microscopes(X 16) may be used
comfort, relatively inexpensive, available in various magnification
• Use of temporary elective tooth separation

12. •Explorers are widely used for the detection of carious tooth structure
-Right angled probe no.6
- Back action probe no.17
- Shepherds crook- no. 23
- Cowhorn with curved ends- no.2
•Dental floss
History of use of explorers
1942- G.V Black:
passing the explorer into pits, noting whether or not there is any
softening & whether the instrument catches or enters any point

13. • Carious lesions are detectable radiographically when there has
been enough demineralization to allow it to be differentiate from
normal
• They are valuable in detecting proximal caries which may go
undetected during clinical examination.
•On average they have around 50% to 70% sensitivity in detecting
carious lesions.
• 40% demineralization is required for definitive decision on caries

14. • Radiographic examinations include: Bitewing radiographs IOPA
radiographs using paralleling technique Dental panoramic
tomograph
• The two important decisions related to radiographic examination
are (1) when to take a radiograph and
(2) how to evaluate a radiograph for presence of signs of dental caries

15. •Xeroradiography
•Digital Radiography
•Digital Substraction Radiography
•Tuned aperture computed radiography

16. Technique simulates that of photo-copying
Xerographic films to record the images produced by X-rays
Image recorded on aluminum plate with a layer of selenium particles and is
given a uniform electrostatic charge
X-rays passes through film-causes the discharge of particles producing a
latent image-converted in a processing unit to positive image.
Advantages
•Edge enhancement
•Less radiation
•Economical
Disadvantages
•Electrical charge may cause discomfort to patients
•Exposure time varies with thickness of film
•Process of development cannot be delayed more than 15 min

17. •Principle: works on a CCD which is electronically connected to computer
•Image is formed and represented by a spatially distant set of discrete
sensors and pixels
CCD-4 major components
•X-ray image detection
• Digitalization
• Image processing
• Image display
• CCD-is a semi-conductor made of metal oxide silicon coated with x-ray
sensitive photons
•Charge coupling is a process whereby the number of electrons deposited
in each pixel are transferred from one well to the next in a sequential
manner to a read-out amplifier for image display on the monitor.

18. Advantages
• No dark room processing
• Reduced radiation dose
• Image manipulation
• Ability to enlarge specific area
Disadvantages
• Cost of the system
• Life expectancy is not fixed

19. •Principle : Optimally, all unchanged anatomical background structures will
cancel, and changed areas will be displayed in a neutral grey shade in the
subtraction image.
•Loss of bone appear in darker shades of grey, and areas of gain appear lighter
than the background
Advantages
•Broader latitude of enhancement
•Reduced in radiation dosage
Disadvantage
•Inability to produce the same geometry
•Density and contrast are not proper

20. • Occlusal and proximal caries : not significantly better than
film or digital radiography.
•Used in early caries and secondary caries detection
•A series of 8–10 radiographic images are exposed at different
projection geometries using a programmable imaging unit, with
specialized software to reconstruct a three-dimensional data set
which may be viewed slice by slice.
• Advantages of TACT over conventional radiographic
techniques is that the images produced have less
superimposition of anatomical noise over the area of interest

21. Fibre Optic Transillumination
Digital Imaging Fibre Optic Transillumination

22. •Principle : decayed matter scatter light more strongly and appear as
darkened shodows
•Light is absorbed more and lower index of light transillumination due
to disruption of crystalline structure of enamel and dentin
•Compressed air used-better visualization

23. Used in the anterior and the premolar
region
Used to detect-enamel crazing – cracks
in the tooth
Advantages – no hazard of radiation,
simple and comfortable for patient, not
time consuming
Disadvantages – limited only for enamel
caries detection, difficult to locate probe
in certain areas, permanent records
difficult to maintain.

24. Components of Digital imaging fiber
optic transillumination :
•Handpieces
•Disposable mouth piece
•Foot control for selecting the images
•Computer

25. Mechanism: light propagates from optical fiber to the tooth
surface-the area of demineralization scatter light and appear
dark
• This image is acquired through CCD camera-and the lesion
can be monitored

26. Advantages
•Doesn’t need ionizing radiation
•Instant images
•Non-invasive
•Early caries, hidden caries
•No film, film processing, mounting and storage
•More sensitive than conventional radiographs
Disadvantages
•Cant determine the depth of lesion
•Learning curve required
•White spots can be mistaken for cavitations

27. •Bejelkhagen & Sundstrom introduced this technique in 1981
•Mechanism : deminerilazation of dental hard tissues cause loss
of its auto-fluorescence. Fluorescence radiance of carious lesion
lower than sound enamel.
•Argon laser ~ 488 nm
•Xenon Arc Lamp ~ 370 nm

28. Blue light is used to illuminate the tooth which causes the tooth to fluoresce
in yellow, green or red.
• Demineralized areas-dark
Intensity of red fluorescence is related to the activity of bacteria.
• Advantages:
• Incipient lesions – 25 μm
• determines amount of mineral loss
• Monitor changes in lesions
Disadvantages :
• On accessible smooth surfaces only
• Cant discriminate between enamel & dentin lesions
• Not suitable for dentin demineralization
• Cant differentiate between decay , hypoplasia
• presence of plaque, calculus

29. DIAGODENT ™

30. Hibst & Gall (1998) – Red Light (638-655 nm) induced fluorescence
could differentiate between sound and carious tooth tissue.
• Light emitted from a Diode laser (wl=655nm). Light transmitted
through descendant optic fiber to hand-held probe – bevelled tip with
fiber-optic eye.
• Organic & Inorganic molecules absorb light – fluorescence occurs
within infrared spectra.
• Signal is processed and displayed as an integer between 0 and 99.
• the device collects fluorescence from maximum extension of carious
lesions on occlusal surfaces – instrument is to be tilted around
measuring site – tip picks up fluorescence from slopes of fissure walls.

31. • To measure both sensitivity & specificity
of lesions
• Detection of occlusal & accessible
smooth surface caries
• Decision making for operative
intervention
•Reproducible method for caries detection
epsl at D2 & D3 levels
•
•Longitudinal monitoring of caries

33. • Electric conductance measurement

34. Principle:
• sound enamel has high resistance to current flow
• carious enamel-porous filled with saliva has low resistance and high conductance
• Conductance increases as lesion progress
• Meters can be calibrated to depth and extent
Circuit –cord attached to a probe which is placed on the tooth-Patient holds it to
complete the circuit
• The electrical conductance between the fissure and area of high conductance are
converted to ordinal scale
Examples
-Vangaurd Electronic Caries Detector
- Caries meter L
- Indicators for Caries L meter are 4 colored lights
-• Green- No caries
-• Yellow- Enamel caries
-• Orange- Dentinal caries
-• Red - Pulpal involvement

35. Indications:
• Pit and fissure caries
• Failure of fissure sealants
Drawbacks
• Results vary due to size of tip used
• Results depend on the type of current used
• Teeth should be dry
False positive results:
• Immature teeth
• Cracks in enamel

36. • Multi-photon Imaging
• Infrared Fluorescence
• Optical Coherence Tomography
• Ultrasound
• Tetrahertz Imaging

37. OCT generates high resolution cross-sectional
images of the oral structures
• Uses light for dental imaging; wavelength of
840 to 1320 nm
• OCT is based on interference of two partially
coherent light beams coming from a single
source.
• Sound enamel shows high intensity back
scattering at the tooth surface. Incipient
lesions shows higher back scattering indicative
of porosity caused by demineralization.
• Identifies incipient lesions, surface integrity
and lesion depth

38. • Principle : Enamel is highly transparent in
the near infrared (NIR), demineralized
areas appear dark due to attenuation
Advantages:
• Lesion more clearly seen than with
bitewing
• Better image contrast at NIR wavelengths
than by X rays
• Can differentiate from stains,
pigmentation, fluorosis & demineralization
• Can examine defects, cracks in enamel
• Can detect incipient lesions not seen in
radiographs

39. • This has been used for the past 30 years & has undergone tremendous
change for the past 5 yrs
• Sound waves are pressure waves that have the ability to travel thro’ gases,
liquids & solid
• Ultrasound waves have frequency > 20,000 Hz that undergo scattered,
reflected, refracted & absorbed
• There is a difference in acoustic impedance between 2 surfaces at the
interface which is interpreted by the difference in the reflected sound
waves
• The amount of reflected sound waves provide information of the
reflecting interface & time taken for sound to be reflected provide info of
the position of reflecting surface under study

41. • Uses waves of terahertz frequency – 1012 Hz & λ - 250µ
• Short enough to provide reasonable resolution but long enough to prevent loss of
information due to scattering
• Photo-conducive emitters / certain crystals like Zn tellurite when exposed to short
pulses of visible light/ infrared light, emit waves of terahertz frequency
• Reflected waves are detected with the help of photo- conducive detectors like a
CCD
• Adverse thermal effects thought to be unlikely
• Low signal : noise ratio facilitates clear imaging
• But long wavelength can reduce spatial resolution
• Terahertz waves are strongly absorbed in water, which may complicate its use in
the oral cavity

42. • MPI uses many infrared photons thus increasing the chance of
absorption of atleast two photons resulting in fluorescence
• Ultra-short pulses (100fs) of 850nm laser light generated at
200MHz results in two photon effect, which is recorded in a
particular focal plane
• Fluorescence for sound tooth > carious tooth
• Plane of focus can be moved thro’ the lesion & record sectional
images to form a 3D image
• Caries appears dark in a fluoresced tooth. Negative images can
be used to highlight the lesion

43. • MPI can measure lesion depths to 500 µ
• Gives a quantifiable measure of mineral
loss in 3 dimensions
• Decreased laser power used in MPI
ensure low risk of photo-toxicity to pulp &
increased depth of penetration
• Only in-vitro studies conducted.
Requires future research to develop laser
equipment used for clinical practice