Recent advances in caries diagnosis

1. RECENT
ADVANCES
IN CARIES
DIAGNOSIS
22/07/2020

2. CONTENTS
 Introduction
 What is diagnosis?
 Requisites of diagnostic tool
 Various diagnostic aids
• Conventional techniques
• Recent advances
 ILLUMINATION METHODS
Fiber-optic transillumination (FOTI)
Digital imaging FOTI (DIFOTI)
CariVu
 ENDOSCOPY
Videoscope
Intraoral television camera
 ELECTRICAL CONDUCTANCE
MEAUSUREMENTS
CARIESCAN
Caries meter
Vanguard electronic detector
 RADIOGRAPHY
Digital imaging radiography
Subtraction radiography
Tuned aperture CT
 LASERS
Quantitative light-induced fluorescence
Diagnodent
MID(midwest caries ID)
 MISCELLANEOUS
Species specific monoclonal antibodies
Infrared thermography
Terahertz imaging
 Conclusion
 Public health significance
 References

3. INTRODUCTION
Dental caries is the localised destruction of susceptible dental hard tissues by
acidic by-products from bacterial fermentation of dietary carbohydrates.
(According to Shafer)
It can be defined as the progressive, irreversible microbial disease of the
calcified tissues of teeth characterized by demineralization of the inorganic
portion and destruction of organic substance of the tooth.
( According to WHO)
Caries is defined as a localized post eruptive, pathological process of external
origin involving softening of the hard tooth tissue and proceeding to the
formation of a cavity.

4. WHAT IS DIAGNOSIS?
• The word diagnosis is derived from the Greek ‘‘dia’’ meaning ‘‘through’’
and ‘‘gnosis’’ meaning ‘‘knowledge’’.
• Thus, ‘‘to diagnose’’ implies that it is only through knowledge about the
disease that a diagnosis can be established.

5. • The PRIMARY OBJECTIVE of caries diagnosis is to identify those lesions that
require restorative treatment, those that require non-surgical treatment, and
those persons who are at high risk for developing carious lesions.

6. • Some decades ago, visual diagnosis (light and mirror) and probing,
supplemented by bitewing radiographs were the only tools available for
clinical diagnosis of caries. For epidemiologic surveys and for examination
of most patients, these are still useful tools.
• Recent years have seen an increase in research activity surrounding
diagnostic methods, particularly in the assessment of early caries lesions.
• The use of technologies as adjunct to clinical visual examination for caries
diagnosis will facilitate preventive care in dentistry to lower treatment cost.

7. Requisites of an ideal diagnostic tool
• Precise/simple
• Useful for all surfaces of teeth
• Identifying caries adjacent to restorations
• Objectivity
• Sensitivity
• Specificity
• Reproducibility
• Validity

8. Sensitivity Vs Specificity
• SENSITIVITY- It has been defined as the ability of a test to identify
correctly all those who have the disease, that is "true-positive".
• SPECIFICITY- It is defined as the ability of a test to identify correctly
those who do not have the disease, that is, "true-negatives".

9. DIAGNOSIS OF DENTAL CARIES
TRADITIONAL
METHODS
RECENT
METHODS

10. TRADITIONAL METHODS

11. RECENT METHODS
ILLUMINATION METHODS
Fiber-optic transillumination (FOTI)
Digital imaging FOTI (DIFOTI)
CariVu
ENDOSCOPY
Videoscope
Intraoral television camera
ELECTRICAL CONDUCTANCE
MEAUSUREMENTS
CARIESCAN
Caries meter
Vanguard electronic detector
RADIOGRAPHY
Digital imaging radiography
Subtraction radiography
Tuned aperture CT
LASERS
Quantitative light-induced fluorescence
Diagnodent
MID(midwest caries ID)
MISCELLANEOUS
Species specific monoclonal antibodies
Infrared thermography
Terahertz imaging

12. Visual diagnosis
● Most common because it is an easy technique that is routinely performed
in clinical practice.
● Permits early caries signs to be detected and recorded in a reliable and
accurate way by using visual indices.
● Indices may also describe the characteristics of all clinically relevant stages
in the caries disease process, making them a cost-effective method of
recording caries lesions.

13. ● Teeth should be cleaned and/or dried before the examination process, which
if not included will increase the risk of missing lesions
● Some indices recommend tactile examination to be performed in conjunction
with visual examination.

14. Visual Tactile diagnosis
•The visual-tactile method has been a mainstay of clinical
dentistry for more than 100 years and is based on the use of
a dental mirror, sharp probe, and a 3-in-1 syringe and
clean and dry tooth surface.
•The examination is primarily based on subjective
interpretation of surface characteristics such as integrity,
texture, translucency or opacity, location, and color.
•Use of dental floss for tactile evidence of proximal
caries has been shown to be effective, wherein shredding of
dental floss indicates a proximal cavity.

15. Disadvantages of Probing with Sharp Explorer:
• Traditional probing with a sharp explorer has come into question as the ultimate
determinant of caries activity.
• Tactile examination using a sharp probe has been criticized because of the possibility
of transporting cariogenic bacteria, may cause irreversible traumatic defects in
potentially remineralizable enamel and may not be able to add any information to the
visual examination.
• In scanning electronic microscopic study by Kuhnisch et al. in 2007 confirmed that
using a sharp probe for caries detection can cause mechanical damage to the enamel.

16. Examples showing the benefit of cleaning and drying to detect caries (A–C)
and harmful effect of probing with a sharp explorer

17. Internationally accepted caries detection system
• DMFT/S index (Klein, Palmer, Knutson 1938, 1987,1997)
• Significant caries index (Sic) (Bratthal D in 2000)
• International and Caries Detection Assessment System (2002,2005 Baltimore,
Maryland, USA)
• Universal Visual Scoring System(UNIVISS) (2008)
• Pulpal Ulceration, Fistula, Abscess Index(PUFA) (Monse et al 2010), etc.

18. Detection with chemical dyes
Fusayama introduced a technique in 1972 that used a basic fuchsin red stain to aid
in differentiating layers of carious dentin.
• Caries-detecting stains differentiate mineralized from demineralized dentin in
both vital and nonvital teeth.
• Outer carious dentin is stainable because the irreversible breakdown of
collagen crosslinking loosens the collagen fibers.
• Inner carious dentin and normal dentin are not stained because their collagen
fibers are undisturbed and dense.
• Dyes do not stain bacteria but instead stain the organic matrix of poorly
mineralized dentin. (Yip et al .,1994)

19. Commercially available caries detector dyes
• Caries check (CC), containing 1% acid red in polypropylene glycol has
been recently introduced.
• Caries marker (cam),
• Seek (see),
• Sable seek (ses),
• Carbolan green,
• Coomassie blue,
• Lissamine blue,
• Snoop,
• Brilliant blue,
• Basic fuschin and calcein

20. RADIOGRAPHIC METHODS

21. Radiographic methods includes:
1. Bitewing radiographs
2. IOPA radiographs
3. Digital radiography
4. Digital subtraction radiography
5. Tuned Aperture computed Tomography

22. Radiographic Appearance Of The Caries:
• Initial enamel - small radiolucent notch.
• Advanced lesions – Diffuse triangle with base to surface of the tooth-in enamel.
● Appears as triangle with base towards DEJ
Advantages :
● Discloses sites inaccessible to other methods.

23. DISADVANTAGES
● Caries are not visible on radiographs until they penetrate more than one half
the enamel thickness and enamel lesions are usually not visible until 40-60%
of the lesion has become demineralized.
● Validity of detecting enamel lesions is limited on the proximal surfaces and
low for the occlusal surfaces. This difference can be explained by the fact
that radiography is a 2-dimensional image of a 3- dimensional anatomy of the
tooth structure. So, the superimposed cuspal tissues obscure initial changes in
occlusal surfaces. (Espelid et al., 1994; Neuhaus et al.,2009)

24. DIGITAL RADIOGRAPHY

25. ● Digital radiology has overtaken conventional screen-film radiography since it
was introduced in the mid-1980s
● The dawn of the digital era in dental radiography came in 1987 with the first
digital radiography system called radio visio graphy (RVG), launched by Dr.
Francis Mouyen.
● There are two types:
Direct – The direct image receptor that collects X-ray directly, for example,
RVG.
Indirect – For example, video camera is used for forming digital images of a
radiograph.

26. Digital detectors
• Charged couple device (CCD)
• Complementary metal oxide semiconductor
• Phosphor plate

27. Advantages of digital radiography compared with conventional
radiography:
•Reductions in radiation dose.
•Time savings.
•Digital manipulation of the image to enhance viewing.
•Avoiding unnecessary or repeated radiographs.
•Facilitate communication and case discussion among dental professionals.
•Visual aid to be shown to the patient on the computer screen, increasing the
confidence and credibility in the treatment-decision making process.
•Primary disadvantages include the rigidity and thickness of the sensors, the
high initial system cost and unknown sensor lifespan.

28. • One important advance with digital radiology was the introduction of caries detection
software, Logicon Caries Detector™ Software (Kodak Dental Systems, Atlanta), for
assisting in the diagnosis of interproximal caries.
• Logicon software extracts image features of the digital radiographic image and correlates
them with a database of known and identified caries problems. This software has the
ability to locate and classify proximal caries, indicating the depth of caries penetration.
• The Logicon program had an increased sensitivity, especially in lesions with caries
extending into the dentin.

29. Digital subtraction radiography
•A digital bitewing radiograph is taken and later a second radiograph of exactly the
same region is produced with identical exposure time, tube current, and voltage
•By subtracting gray values for each coordinate of the first radiograph from equivalent
coordinate of second, a subtraction image is obtained.
•If no changes have occurred, the result of subtraction is zero.
•Non zero result will be obtained in case of onset or progression of demineralization.
•It is not yet routinely applied in clinical caries detection due to difficulty of image
registration.
Advantages:
•Detects onset or progression of demineralization.
Disadvantages:
•Difficulty of image registration

30. Tuned-aperture computed tomography

31. Tuned-aperture computed tomography
• This method constructs radiographic section through teeth. The slices can be
viewed for the presence of radiolucency
• Series of radiographs taken in different angles.
• Used for caries detection, vertical root fracture, osseous defects
• Low cost , low dose than conventional CT.
• Technique sensitive.

32. ILLUMINATION
METHODS

33. Fiber-optic transillumination (FOTI)
• FOTI was initially designed by Friedman and Marcus in 1970
• It refers to flexible, thin cylindrical fibers of high optical-
quality glass or plastic
• Single optical fiber that consists of glass or plastic material
with an outer cladding of a material with lower refractive
index.
• Fiber core has a higher refractive index.
• Individual fibers are grouped together to form a fiber optic
bundle.
• Fibers can be as small as 0.01mm for glass and 0.1 mm for
plastic.

34. Fiber-optic transillumination (FOTI)….
• Based on the phenomenon of light scattering.
• The light that is shone through the tooth scatters and observed shadows may
indicate the presence of a carious lesion. The reason why shadows may
indicate caries is because demineralized areas of enamel or dentine scatter
light more than sound areas. Hence, caries appear as darker areas under FOTI.

36. ADVANTAGES
• It is simple, noninvasive, painless procedure that can be used repeatedly with
no risk to the patient.
• The research around FOTI with a recent review finding a mean sensitivity of
only 14 and a specificity of 95%.

37. DISADVANTAGES
• The system is subjective.
• Furthermore, foti can only be used for coronal tooth surfaces (occlusal,
interproximal, and smooth) and not below the gingiva.

38. Digital imaging FOTI (DIFOTI)
• DIFOTI system consists of two handpieces (one for occlusal surface and one for
smooth surface and interproximal areas), a disposable mouthpiece, a foot pedal
for selecting the image of interest and a computer system to capture and store
the resulting image.
• It is based on the principle that carious tooth tissue absorbs more light than
surrounding healthy tissue and appears as darker area.
INTRODUCED IN YEAR1998
• Developed by Schneidermann et al, Department of Oral
Pathology, Radiology and Diagnostic Sciences, New Jersy
Dental School, University of Medicine and Dentistry of
NewJersey.

39. Digital imaging FOTI (DIFOTI) …
ADVANTAGES
• Detects initial areas of demineralization
• Inspects integrity of teeth
• Detects cracks, tooth fractures, and wear
• No harmful radiation
• Uses safe white light Images all coronal surfaces including interproximal,
occlusal, smooth surfaces
• Determines depth of lesion accurately
• Only dental diagnostic imaging instrument approved by the Food and Drug
Administration for detection of incipient and recurrent caries
• Magnification of up to ×16

40. Digital imaging FOTI (DIFOTI) …
DISADVANTAGES
• Technique sensitive
• High cost

41. CariVu- Compact, Portable Caries Detection Device
● DEXIS CariVu is a compact, portable caries
detection device that uses transillumination
technology to support the identification of
occlusal, interproximal and recurrent carious
lesions and cracks.
•Uses transillumination technology that makes enamel appear
transparent while porous lesions trap and absorb light
•Allows the clinician to see through the tooth, exposing its structure
and the development of any carious lesions
•CariVu images read like familiar X-ray images
•Uses non-ionizing radiation which is ideal for children, pregnant
women and cancer patients who are X-ray averse

43. ENDOSCOPE BASED
DIAGNOSIS

44. INTRAORAL
TELEVISION
CAMERA (IOTV)
• IOC systems consist of video display, processing unit, and intra-oral camera
with a light source.
• These sensors receive light which is converted to an electronic signal that is
processed by IOC imaging software to produce an image on the computer
monitor.
• The LED lighting provides a continuous source of light to eliminate the
need for a flash. Images captured by most of the IOC are stored in the in-
built memory or can be stored in the computer.

45. • Widely ranged features for intra-oral cameras including Macro mode
(magnification), curing light for composite, LED lights, picture or video record,
fluorescence for detecting various stages of caries, plaque and gingival
inflammation.
• Through the IOTV, the dentist can educate the patient and at the same time, can
also improve their own diagnostic expertise as they see magnified oral
conditions which are significantly better than direct vision.

46. Boye et al. compared diagnostic performance for the detection of caries using
photographs (taken with intra-oral camera) with an established visual
examination method and histological sections as the reference standard and
concluded that the photographic assessment method had higher sensitivity for
caries detection than visual examination.

47. ELECTRIC CURRENT BASED
DIAGNOSTICS

48. Electrochemical machining (ECM) is based on the principle that a demineralized
tooth has more pores filled with water or saliva, and this is more conductive
than intact tooth surface.
It was first proposed by Magitot in 1878. Greater the amount of
demineralization, higher is the electrical conductivity through enamel.
Demineralized sites and sites with high pore volume and cavities can be detected
by measuring the conductance.

50. VANGUARD ELECTRONIC CARIES DETECTOR:
• It used a current of 25 Hz. Measured conductance was then converted to an
ordinary scale of 0–9. Moisture and saliva were removed by a continuous stream of
air to prevent surface conductance.
CARIES METER:
• It used a current of 400 Hz. Measured conductance was then converted to four
colored lights.
Green: No caries
Yellow: Enamel caries
Orange: Dentin caries
Red: Pulpal involvement.

51. CARIESCAN
• This device is based on alternating current
impedance spectroscopy and involves the passing of
an insensitive level of electrical current through the
tooth to identify the presence and location of the
decay.
• It is the first dental diagnostic tool to use an
impedance spectroscopy to quantify dental caries
early enough to enhance preventive treatment.
• It provides a qualitative value based on the disease
state rather than the optical properties of the tooth.

52. CARIESCAN
• Bader et al. carried out a systematic review comparing CarieScan with a
clinical visual examination, bitewing radiograph, and DIAGNOdent reported
CarieScan to have superior sensitivity and specificity both 92.5% over other
methods.
• The available data on clinical studies is at present minimal.

53. FLUORESCENCE BASED
DIAGNOSTICS

54. Quantitative light-induced fluorescence (QLF)
•QLF system consists of a hand-held intraoral micro CCD camera, interfaced with
a personal computer and custom software.
•The software enables to capture and analyze images of the tooth during clinical
examination.
•QLF uses a 50-watt xenon arc-lamp and filter in order to produce a blue light with
a 290- to 450-nm wavelength, which is carried to the tooth through a light guide
fitted with a dental mirror.
•The fluorescence images are filtered by a yellow high-pass filter (λ ≥ 540 nm) and
then captured by a colour CCD camera.
•When the tooth surface is illuminated by this high-intensity blue light, caries
presence shows red fluorescence.

55. ● Red fluorescence which has been detected in
QLF images has been supposed to be associated
with caries risk.
● Red fluorescence is found in more advanced
lesions (dentinal lesions), progressive white
spots and in aged plaque as well as in calculus

56. DIAGNODENT
• A laser examination tool for the early detection of decay.
• At the specific wavelength that the device operates(655 nm), clean healthy tooth
structure exhibits little or no fluorescence, resulting in very low scale readings on
the display.
• However, carious tooth structure will exhibit fluorescence, proportionate to the
degree of caries, resulting in elevated scale readings on the display.

58. Goel A, Chawla HS, Gauba K , Goyal A. Comparison of validity of DIAGNOdent with conventional methods for detection of occlusal
caries in primary molars using the histological gold standard: An in vivo study. J Indian Soc Pedod Prevent Dent 2009;27(4):227-234
DIAGNOdent showed higher sensitivity and accuracy as compared with other conventional
methods for detection of enamel caries, whereas for detection of dentinal caries, even
though the sensitivity was high, accuracy of the DIAGNOdent device was similar to other
conventional caries diagnostic methods.
• To compare the in vivo effectiveness of diagnodent with other conventional methods (visual, tactile and bitewing
radiographs) for the detection of occlusal caries in primary molars.
• Eighty-four primary molars in 52 children (aged 8–12 years), which were indicated for extraction, were selected and
evaluated for dental caries using diagnodent, visual and tactile examination and bitewing radiographs.
• Histological examination of the sections, prepared subsequent to extraction of the teeth, served as the gold standard for
comparison of the above-mentioned methods.

59. MIDWEST CARIES ID™ (MID)
MID is a small, battery-operated technology that emits a soft LED light for
detecting caries. A specific fiber optic signature captures the resulting
reflection and refraction of the light in the tooth and is converted to
electrical signals that run through a computer-based algorithm for analyzing
the presence of caries.

60. Patel et al. reported the sensitivity and specificity for this detection device as 0.56
and 0.84, respectively.
Useful in detecting the presence of demineralization, but cannot be utilized to
adequately assess the depth of the demineralization
Patel SA, Shepard WD, Barros JA, Streckfus CF, Quock RL. In vitro evaluation of Midwest caries ID: A novel light-emitting diode for caries detection.
Oper Dent 2014;39:644-51.

61. RECENT
ADVANCES
IN CARIES
DIAGNOSIS

62. MISCELLANEOU
S

63. TERAHERTZ IMAGING
• This method uses waves in terahertz frequency (10¹² Hz or a wavelength of
30μm).
• Terahertz Pulsed Imaging (TPI) has great potential for medical applications
since it is a nondestructive imaging method.
• It does not cause any ionization hazard on biological samples due to low energy
of THz radiation.
• Low powers are used for imaging.

64. TERAHERTZ IMAGING…
• Erbium (Er) is employed for optical excitation.
• It generates pulses at a center wavelength of 1550 nm with a repetition rate
of 89 MHz and a pulse duration of 230 fs.
• Output of the laser is separated into a pump beam which is used to generate
THz pulse
• Terahertz waves are capable of diagnosis dental caries.
• The images are clear but due to long wavelength of the source
spatial resolution is low.
• Limited studies concerning this method of imaging are promising.

65. INFRARED THERMOGRAPHY
• The thermal energy emitted by sound tooth structure is compared with that
emitted by carious tooth structure.
• The method uses indium thermal sensors, which can detect temperature changes
in the order of 0.025°C. With a constant flow of air over the surface of the tooth,
the change in temperature of the lesion is compared with that of the sound tooth
structure.
• The source-to-sensor distance is 20 cm, and the time taken to capture the data for
a lesion is up to 2 min.

66. INFRARED THERMOGRAPHY..
• The technique has not been used intra-orally. This technique was considered
efficient for in vitro studies.
• Problems will exist in relation to variations in the temperature of the mouth with
respiration or fluid evaporation from other oral surfaces.

68. SPECIES SPECIFIC MONOCLONAL ANTIBODIES
• This was given by Shi et al. in 1998, identified specific monoclonal antibodies
that recognize the surface of cariogenic bacteria.
• Highly species-specific monoclonal IgG antibodies against S. mutans that
quantitatively detect S. mutans in <1 min and is sensitive enough to detect a
single bacterial cell.
• MAb-based salivary S. mutans tests exhibit significantly higher specificity and
sensitivity than the commonly used selective culture method and thus provides
useful information and tools for analyzing the role of S. mutans in human dental
caries.
• Advantages include that it can be used at chairside by dentist, quick results, and
the overall risk assessment can be made in operatory itself.

69. CONCLUSION
• Unfortunately there is no single diagnostic method on the horizon that can
reliably detect pre-cavitated carious lesions with all advantages and can be
called as ideal.
• The prospects look favorable that, with continued research, laser fluorescence,
quantitative light induced fluorescence, electrical conductivity measurements,
direct digital radiography, and digital fiberoptic transillumination, will provide
the high degree of sensitivity and specificity needed to detect early dental
caries.

70. PUBLIC HEALTH SIGNIFICANCE
• Visual-tactile method(with appropriate Index) plays a key role in Public Health
Programs. Dental caries index helpful in detection of oral diseases on large scale in
field survey.
• It provides data to support recommendations for public health interventions to
improve the health status of population.
• If the non-cavitated lesions had been omitted, a very important message about the
disease prevalence and severity in this population would have been missing.

71. REFERENCES
• Hall A, Girkin JM. A review of potential new diagnostic modalities for carious lesions. J Dent Res
2004;83:C89-94
• Mohanraj M, Prabhu VR, Senthil R. Diagnostic methods for early detection of dental caries-A review. Int J
of Ped Rehab. 2016;10(1):29-35.
• Anusavice KJ. Present and future approaches for the control of caries. J of Dent Ed.2005;69(3):538–54.
• Wang J, Sakuma S, Yoshihara A, Kobayashi S, Miyazaki H. An evaluation and comparison of visual
inspection. Electrical caries monitor and caries detector dye methods in detecting early occlusal caries in
vitro study. J of Dent Health.2000;50(2):223–30.

72. Diagnosing an illness is an art. If the diagnosis is wrong, most
probably so is the treatment.