3. why caries lesion diagnosis
is important:
The scientific literature points to three main reasons
why caries lesion diagnosis is important
1. To achieve the best health outcome for the patient
by classifying caries lesions corresponding to the
best management options for each lesion type.
Lesions are currently classified in the following
way:
• cavitated lesions (where a hole has developed in the
tooth that needs to be restored by operative
intervention, such as a filling)
4. • non-cavitated lesions (which can be helped
by non-operative intervention and
prevention, such as brushing with fluoride
toothpaste)
• active lesions (which indicate ongoing mineral
loss, and can be helped by non-operative
measures)
• non-active lesions (which do not require
intervention because biofilm metabolic
activity is unlikely to lead to mineral loss).
5. 2.To inform the patient.The patient is the key in the
management process because their cooperation is
crucial in controlling the disease and slowing or
reversing caries progression.Therefore, providing them
with as much information as possible about the caries
diagnosis is very important.
3.To monitor the clinical course of the disease.
Long-term monitoring of caries lesions and recording
changes in activity status or surface integrity is the only
way to tell if caries is worsening or getting better
6. An active lesion that becomes inactive is a
positive outcome, while active lesions that
remain active reflect a lack of compliance or
cooperation on the part of the patient, and
profes
Current Concepts andTechniques for Caries Excavation andAdhesion to
Residual Dentinal intervention
7. CARIES DIAGNOSIS
The main task for the
dentist is not to find out
what disease the patient has,
has but having identified by
the patient with dental
caries, to determine
what the course of treatment
is to best control the biofilm
disease process.
8. Also, the dentist needs to identify whether
or not individual teeth have caries lesions,
with the help of screening even patients
who do not have obvious signs of caries,
and determining which treatment can best
help the patient , therefore, in the dental
perspective of caries diagnosis, diagnosis
consists of both identifying caries as a biofilm
disease and managing it,
9. and identifying specific signs and symptoms of
caries, the demineralization to lesion
continuum and managing the lesion activity;
working under the logic that caries can be
prevented, slowed, stopped, or even reversed
through the process of remineralization if it is
detected and treated before it progresses to a
point that requires invasive intervention.
Current Concepts andTechniques for Caries Excavation andAdhesion to
Residual Dentin
10. Diagnosis vs. Detection and
Assessment
The diagnosis of dental caries should be based
on a known disease indicators and risk factors
for the disease.
11. Caries disease indicators
Caries disease indicators include:
• visible cavitations,
• active white-spot lesions,
• interproximal radiographic lesions
penetrating to the dentin, and a history of
any cavitations in the previous 2 to 3 years.
12. lesion detection
employs an objective process to establish
whether any signs of the disease are present
at the time of evaluation.
If demineralization at any stage is observed—at
whatever stage—it is labeled as dental caries.
Once it has been determined that a lesion is
present, the function of lesion assessment is
to classify the lesion and observe it over time
Current Concepts andTechniques for Caries Excavation andAdhesion to
Residual Dentin.
14. Visual tactile method
Visual and tactile methods typically go hand in
hand, because most dentists use dental probes and
other tools to examine teeth during the clinical
examination, which can be annually, twice a year, or
more frequently depending on the dentist’s
recommendation. The first visual indication of caries
in enamel is generally a small white lesion on
smooth surfaces or light to dark brown lesion in pits
or fissures where demineralization has occurred
under the dental plaque.
15. However, grayish lesions also can be seen at
the level of dentin, and in more advanced
stages, caries can appear as open cavities
on enamel, dentin layers, or all the way to
the pulp.
16. Tools
The traditional method of detecting caries
signs is by visual inspection of dental
surfaces, with the aid of a bright light and
dental mirror if necessary to see teeth from
all angles. Reflecting light onto the mouth
mirror also can be done to search for dark
shadows that could indicate dentin lesions.
While the use of a dental probe continues to
be controversial, it is extremely helpful when
used correctly and judiciously .
17. A dental probe can be used to remove plaque
that may be covering lesion, and when the blunt
side of the probe is used, it can help remove
biofilm to check for signs of demineralization
and to assess the surface roughness of a lesion.
Studies show that gentle probing does not
disrupt the surface integrity of non-cavitated
lesions, while vigorous poking can cause
irreversible damage to the surface of a
developing lesion.The accuracy of caries
detection does not increase if probing is used. A
probe is unnecessary if visual inspection detects
a cavity.
18. During a visual–tactile examination, the
dentist will also use a syringe or drying tool to
blast air on to the tooth, which makes it
easier to see some lesions.
19. Other tools used in visual–
tactile examination
may include magnifying devices to look at
teeth, or orthodontic elastic separators to
separate teeth over the course of 2 to 3 days
for a closer look between teeth prone to
caries lesions. Fiber-optic transillumination is
also sometimes used.This is a method by
which visible light is emitted through the
tooth using an intense light source. If the
transmitted light reveals a shadow, this may
indicate a carious lesion.
20. Diagnostic Criteria
Numerous methods have been suggested for
recording lesions and carious lesion activity.
Some of the most commonly used visual–
tactile or visual criteria that have been used in
the recent past include
21. Recording cavitated lesions
Recording cavitated lesions only Working
under the assumption that it is still not
possible to reliably diagnose all non-cavitated
lesions, theWorld Health Organization
recommends that caries lesions be diagnosed
at the level of cavitation only.This is done
with the use of a probe.
22. Because the focus is only on open cavities, it
ignores the fact that non-operative
interventions (such as fluoride) can help
reduce caries risk and progression.Therefore,
most dentists in developed countries today
do not rely solely on this criterion.
23. Recording both cavitated and
non-cavitated lesions
In addition to taking note of cavitated lesions
that can be helped by operative intervention,
taking note of non-cavitated lesions (white
spots that indicate where demineralization
has occurred) can help the dentist observe
where non-operative intervention might be
useful. Pitts and Fyffe (1988) devised the
following diagnostic levels that are still used
today, and devised this method with the help
of a mouth mirror and probe:
24. D1 (enamel lesion, no cavity)
D2 (enamel lesions, cavity)
D3 (dentin lesions, cavity)
D4 (dentin lesions, cavity to the pulp).
25. Lesion depth assessment
To understand the classification for lesion depth
assessment, it is important to know how
moisture on the tooth surface affects the
visibility of a lesion.White spot lesions become
more opaque in dried dental tissue compared to
wet dental tissue because of increased light
scattering.Typically, non-cavitated lesions that
are visible on a wet tooth have penetrated
deeply, while a non-cavitated lesion that is only
visible after drying has penetrated less deeply
into teeth.
26. Based on these concepts, Ekstrand et al
(1997) presented a visual ranked scoring
system for lesion depth assessment that is
still commonly used. Using no probe, they
examined tooth surfaces to devise the
following diagnostic levels:
No or slight change in enamel translucency
after 5 seconds of air-drying
Opacity or discoloration that is hardly visible
on wet surfaces, but visible after 5 seconds of
air drying
27. Opacity or discoloration that is visible
without air-drying
Localized enamel breakdown with opaque or
discolored enamel and/or grayish
discoloration from underlying dentin
Cavitation in opaque or discolored enamel
exposing dentin
28. Lesion activity assessment
This is a newer diagnostic method developed by
Nyvad et al that focuses on the surface
characteristics of lesions, namely activity as
reflected in the surface texture of the lesion, and
surface integrity, as indicated by the presence or
absence of a cavity or microcavity in the surface.
The rationale behind the method is that the
surface characteristics of enamel change in
response to changes in the biofilm covering the
tooth surface..
29. The diagnostic categories are as follows:
active, non-cavitated;
active, cavitated;
inactive, non-cavitated;
inactive, cavitated; filling;
filling with active caries;
filling with inactive caries
30. Active, non-cavitated enamel caries lesions have
a whitish/yellowish opaque surface, with a chalky
or neon-white appearance, and the surface feels
rough when a probe is moved across it.
Inactive, non-cavitated lesions, on the other
hand, are shiny and can vary in color from white,
brown, or black, and will feel smooth with gentle
probing.
Active, cavitated lesions feel soft or leathery,
while inactive, cavitated lesions are shiny and
feel hard with probing.
In general, active, non-cavitated lesions have a
higher risk of progressing to a cavity than
inactive, non-cavitated lesions, which have a
higher risk of becoming a cavity than healthy
surfaces
31. Recording root-surface
caries
This is a classification specific to root caries
lesions that integrates activity assessment
and surface integrity assessment.The
diagnostic categories are as follows:
inactive lesion without surface destruction
inactive lesion with cavity formation
32. active lesion without surface destruction
active lesion with surface destruction
(cavitation), but visually cavity does not
exceed 1 mm in depth
active lesion with a cavity depth exceeding 1
mm, but does not involve pulp
lesion expected to penetrate into pulp
filling confined to root surface or extending
from a coronal surface to root surface
filling with an inactive lesion (secondary)
confined to the margin
33. Recording recurrent caries.
This refers to caries at the margins of restorations,
with recurrent caries reflecting the result of
unsuccessful plaque control.These are typically
found on the gingival margins of all classes of
restorations, with the exception of class I
restorations, which affect pit-and-fissure crevices on
occlusal, buccal, and lingual surfaces of posterior
teeth and lingual surfaces of anterior teeth.
Diagnosis is accomplished using the Nyvad criteria in
the lesion activity assessment section described
previously.
Current Concepts andTechniques for Caries Excavation and Adhesion to
Residual Dentin .
34. International Caries
Detection and Assessment
System (ICDAS)
The ICDAS criteria for visual examination and,
when indicated, radiographic examination,
should be followed to assess the extent and
severity of caries lesions.The ICDAS categories
of caries lesion severity correlate well with
histological depth of caries demineralization in
both enamel and dentin. It should be noted that
the histological depth of lesions correlates with
demineralization but not necessarily with
bacterial penetration.
35. Diagnostic Criteria for
Assessing Coronal Caries
Lesion Activity
An Active Lesion is considered to have a
greater likelihood of transition (progress,
arrest or regress) than an inactive lesion.
An Inactive (arrested) Lesion is considered
to have a lesser likelihood of transition than
an active lesion
42. Diagnostic Criteria for
Detection of Root Caries and
Assessing Root Lesion
Activity
For the purposes of root caries detection, removal of
calculus and plaque is recommended.
The characteristics of the base of the discolored area
on the root surface can be used to determine
whether or not the root caries lesion is active.
These characteristics include texture (smooth,
rough), appearance (shiny or glossy, matte or non-
glossy) and perception of texture on gentle probing
(soft, leathery, hard).
43. Active root carious lesions are usually located
within 2mm of the crest of the gingival
margin.
44.
45. Radiographic Examination in
the ICCMS
There is a unanimous agreement that more
carious lesions can be identified by combining
radiographic information with clinical findings,
compared to visual inspection alone. For this
reason, ICCMS recommends the inclusion of
radiographic examination, if possible and
appropriate based on local safety standards.
Radiographic examination is useful to confirm
the extent of caries, to detect lesions where
visual examination of the tooth surface is
hampered and to serve as an aid in making
appropriate clinical decisions.
46. In addition to the use of radiographic
evaluation, the ICCMS recognizes the
potential benefits that can be gained by the
use of additional, supplemental detection
aids as a means of enhancing caries
detection.These can include Fiber-optic
Transillumination (FOTI), electrical
conductivity measures and optical
fluorescence techniques and are briefly
discussed later in this course.
48. Benefits of Visual Diagnosis
Visual diagnosis is quick and easy to perform,
does not need expensive equipment, and can
be completed without unnecessary radiation.
Currently, activity assessment according to
the criteria suggested by the ICCMS is
considered the best choice for performing a
caries diagnosis. Surprisingly, data show that
when non-cavitated lesions are included in
classification, the yield of visual or visual–
tactile caries examination is
49. greater than that of radiographic examination
because minor mineral losses cannot be
detected in radiographs.
50. Limitations of Visual or
Visual–Tactile Lesion
Diagnosis
These include the fact that visual or visual–
tactile diagnosis requires subjective evaluations
to be made by the practitioner, lesions can go
undetected because teeth are typically
examined by the naked eye, and there is need for
supplemental analysis when faced with clinical
signs that will leave a dentist uncertain, including
dark occlusal or approximal shadows.
Current Concepts andTechniques for Caries Excavation and
Adhesion to Residual Dentin
51. Caries Lesion Diagnosis:
Bitewing Radiography
The most commonly used radiographic method for
detecting caries lesions is the bitewing technique. It is
meant to find lesions that are hidden from a
clinical visual
examination,
such as when
a lesion
is hidden by an
adjacent tooth,
as well as help the dental professional estimate how deep
the lesion is.
52. To get the radiographic images, a central beam
of X-rays is positioned to pass at right angles to
the long axis of the tooth. If film is used, a beam-
aiming device on the film holder guides the
position, directing the beam at right angles to
the film. However, digital radiography is
replacing radiography based on film. It has been
proven as accurate as traditional radiography for
detecting caries, and it comes with additional
advantages of using a lower radiation dose,
being less time-consuming, and does not require
wet chemicals in the processing of the image.
54. Concerns about Radiation
Possible health risks of exposure to low-dose
radiation in children, who appear to be more at risk
than adults, include parotid, bone marrow, and
thyroid cancer. Even though there is no conclusive
evidence that the small, infrequent doses of
radiation from dental radiographs increase risk of
malignant disease, unnecessary radiation to the
patient should be avoided, and care used to reduce
radiation exposure if radiography is necessary.This
can include use of a thyroid shield, use of a
rectangular collimation which limits the shape of the
X-ray beam and reduces radiation exposure by 50%,
or use of the fastest film type (the F-type) or digital
radiography.
55. Factors that Influence the
Quality and Interpretation
of Radiographic Images
There are a number of factors that affect the
usefulness and quality of the radiographic
examination.
1. A certain amount of mineral must be lost
before it can be detected in a radiograph.
Technical aspects, such as film contrast and
viewing conditions, determine this minimum
amount of mineral loss
56. 2.The shape, extent, and location of the
lesion, together with the anatomy of the
tooth, also influence the radiographic
depiction. A shallow, widespread lesion may
create an image of being deeper than a deep
lesion that is narrowly spread on the surface.
3.The direction of the X-rays affects the
image. Most dentists now use film-holders or
beam-aiming devices that prevent deviations
of the rays that cause a decreased image
contrast, and could result in the under- or
over-estimation of the extent of a lesion.
57. 4. An important aspect of correctly
diagnosing caries using radiography is the
interpretation by the professional. Having no
expectation to detect caries may result in
insufficient examination of the image, a
neglected diagnosis, and insufficient
treatment. On the other hand, there is also
the possibility of over diagnosis and
overtreatment if a dentist assumes almost all
patients have caries.Therefore, it is
important to understand caries prevalence of
the population under treatment, meaning
that not all patients should be handled in the
same way.
58. Timing of Bitewing
Radiography
For populations with low caries prevalence, or in
individuals who are at low risk for caries based on
their medical and dental history, yearly bitewing
radiographs are no longer justified. Instead, the
decision to use radiography should depend on the
benefit to the individual patient as it related to the
risk and cost of low-dose radiation exposure. Studies
have confirmed that in low-risk populations,
intervals of up to 3 years between bitewing
radiographs do not jeopardize dental health. Based
on epidemiological data, four key ages have been
identified when bitewing examinations are
beneficial.These are at
59. Age 5, when it gives a considerable diagnostic
yield of otherwise undetected approximal
lesions in primary molars.
Age 8–9, when the first permanent molar has
been in contact with the second primary molar
for about 2 years, and these surfaces are,
therefore, at risk of approximal caries.
Age 12–14, when even in low caries-
prevalence populations, one in five children
has at least one approximal lesion that has
been overlooked without bitewing
radiography.
Age 15–16, when it is the first 3 to 4 years
after tooth eruption and the establishment of
approximal contacts create the risk of new
approximal lesions.
60. In adults, the caries process is slow compared
to children and adolescents, but rapid
behavior and lifestyle changes can quickly
increase caries risk and progression. Keeping
an eye out for these changes by taking a
patient’s medical and dental history can help
a dentist decide when it might be useful to do
a bitewing examination. Special attention
should be paid to the third molar and distal
surface of the second molar because the
location is usually associated with plaque
removal difficulty.
61. Bitewing Radiography as a
Complement to the Visual–
Tactile Examination
Occlusal caries lesions (which develop on
surfaces that contact an opposing surface of a
tooth in the opposing jaw) are difficult to
diagnose by visual examination only. Using
bitewing radiography raises the sensitivity of the
diagnosis if obvious dentin caries activity is to be
detected, but can be inaccurate if diagnosing
enamel occlusal caries activity.Visual–tactile
examination alone also fails to detect a number
62. of occlusal and approximal caries lesions in
deciduous teeth in children. Complementing
the clinical examination with bitewing
radiography has also been found to increase
the sensitivity of detecting caries lesions in
these teeth. Another way in which bitewing
radiography complements the visual–tactile
examination is in the diagnosis of recurrent
caries lesions. A radiolucent area typically
indicates that residual carious tissue was left
behind when the restoration was placed.
63. Benefits of Bitewing
Radiography Diagnosis
As mentioned previously, bitewing radiography
allows accessibility to surfaces that may not be
seen in the clinical visual–tactile examination,
and allows the depth of lesions to be assessed.
Other advantages are that it is not invasive, and
does not damage tooth structure like an
incorrectly used dental probe might.
Radiographs can also be filed and reexamined at
a later date to compare with a more recent
image to detect whether a lesion is progressing
or not.
64. Limitations of Bitewing
Radiography Diagnosis
Besides concerns about low-dose radiation and variations
in how images are interpreted by dentists, the main
limitation is that the validity in diagnosing early lesions is
rather low. Also, the bitewing radiograph cannot always
distinguish between sound surfaces, those with initial caries
activity and cavitated lesions, or non-carious
demineralizations, so clinical inspection is still needed to
determine what is happening to the tooth. Bitewing
radiographs also tend to underestimate the depths of
lesions, so a lesion that appears confined to the inner
enamel on an image is often actually in the dentin, and this
can lead to insufficient or improper treatment.
Current Concepts andTechniques for Caries Excavation and
Adhesion to Residual Dentin
65. Caries Lesion Diagnosis:
Newer Methods of Caries
Detection and Assessment
Methods Based on X-Ray
Digital radiography
Digital image enhancement
Digital subtraction radiography
Tuned aperture computed tomography
Methods Based on Light
Laser light-induced fluorescence
66. Quantitative laser-light induced fluorescence
DIAGNOdent
Fiber-optic transillumination (FOTI)
Current Concepts andTechniques for Caries Excavation and Adhesion to
Residual Dentin
67. Caries-disclosing Dyes
It is stated that characterization of carious
dentin revealed that the most superficial carious
layer is necrotic, highly decalcified, and contains
irregularly scattered granular crystals and
irreversibly denatured collagen fibrils.
Underneath this “caries-infected” dentin, the
deeper “caries-affected” dentin layer exhibits
decreased collagen crosslinks, but comprises
needle-like apatite crystals, regularly attached to
collagen fibrils with no signs of bacterial
invasion.
68. Based on this knowledge, the ideal caries-
disclosing dye should stain solely the
caries-infected, but not the caries-affected
dentin.
69.
70. 0.5% Basic fuchsin in a
propylene glycol base
One of the first caries-disclosing dyes was based on
a solution of 0.5% basic fuchsin in propylene
glycol and was claimed to stain exclusively the
top, irreversibly destroyed carious layer, enabling
differentiation from what could be left in the
cavity.The mechanism of this differential staining
was initially ascribed to the irreversible collagen
denaturation of caries-infected dentin, caused by
breakdown of the intermolecular crosslinks
through bacterial lactic acid.Later,
71. the differential stainability was attributed
rather to differences in the degree of
mineralization in the carious lesion than
being specific for denatured collagen
fibrils.The exact mechanism for the
differential staining is however still
unknown
72. The first combined clinical/laboratory study on the
reliability of this caries-disclosing dye has
pointed out that the extent of dentin excavated
by the fuchsin-guided method was larger than
the extent of demineralized dentin, as shown by
conventional dental radiographs taken before
histological sections were made. Later, others
also showed that when caries was removed using
conventional tactile probing to determine the
caries removal endpoint, both in primary and
permanent teeth, the cavity walls and floors
were still fuchsin-stainable.
73. Some concerns were also raised regarding
possible carcinogenic effects of fuchsin for
intra-oral use,and for this reason,
alternative caries-disclosing dyes are
sought
74. 1% Acid-red in propylene glycol
base
Although a 1% acid-red solution was launched as
an alternative to fuchsin for intra-oral use,clinical
inconsistencies have been reported when
assessing the presence of stained tissue at the
DEJ by means of the usual tactile probing
method.Two studies have shown that more than
half of the teeth judged clinically as having no
caries at the DEJ could be stained with acid red.
Microbiological assessment of the caries-stained
and stain-free dentin at the DEJ failed to disclose
differences in level of infection.
75. Moreover, it has been demonstrated that a 1%
acid-red solution can lead to staining of dentin
clinically judged as“sound”, with a 30% false
positive diagnosis of residual caries.
At the pulpal floor, also more than half of the teeth
diagnosed as having “hard” and “sound” pulpal
floors still took up some stain. In fact, it has been
reported that sound circumpulpal dentin takes
up stain more easily, because of its lower degree
of mineralization For all these reasons, the use of
caries-staining agents is still much criticized.
76. Comparing acid red to basic fuchsin, both in
propylene glycol bases, acid-red produces a less
intense and less bound stain with a more intense
staining of the outer than the inner layer of
carious dentin.
Further in vitro studies have shown that the light
pink staining from acid red, typically seen at the
inner layer of carious dentin, was related to a low
degree or absence of bacterial infection as well
as to a low level of peritubular dentin dissolution
and increased hardness.For these reasons, the
lightly stained tissue should not be removed
77. Another concern is that the propylene glycol base
of both staining agents can easily penetrate into
normal dentin due its low molecular weight (76
MW), which could thus also explain the over
staining frequently reported for commercial
products, such as Caries Detector.This finding
has recently led to the introduction of a 1% acid-
red dye in a polypropylene glycol base.
The higher molecular weight of polypropylene
glycol (300 MW) makes it more caries specific
than a propylene-glycol-based dye.
78. The fluorescence readings of residual
dentin using DIAGNOdent after caries
removal guided by acid red in
polypropylene- glycol-based dye were
higher than those when caries was
removed using a propylene-glycol-based
dye, indicating that less dentin was
removed with the former caries-disclosing
dye.
79. Clinically, both formulations of Caries Check
(1% acid red or a 1% brilliant blue dye in a
polypropylene glycol base) also produced
significantly lower DIAGNOdent readings
after caries removal than 1% acid red in
propylene glycol.The blue version of the dye
was introduced to facilitate identification of
caries in heavily stained cavities, where the
red color is more difficult to differentiate.
80. refrences
Current Concepts andTechniques for Caries
Excavation and Adhesion to Residual Dentin
Aline de Almeida Nevesa/Eduardo
Coutinhob/MarcioVivan Cardosoc/Paul
Lambrechtsd/BartVan MeerbeekeCurrent
Caries
81. New technologies for
clinical diagnosis of early
dental caries
Fiber-optic transillumination
Digital imaging fiber-optic transillumination
Quantitative light-induced fluorescence
DIAGNOdent laser system
Electrical caries monitor
Midwest Caries I.D
Polarization-sensitive optical coherence
Tomography
CarieScan
82. Frequency-domain infrared photothermal
radiometry and modulated luminescence
Cone beam computedTomography.
Emerging technologies for diagnosis of dental caries:
The road so far BennettT. Amaechia Department of Community Dentistry,
University ofTexas Health Science Center at San Antonio,San Antonio,Texas
78229,USA
83. 1. Fiber-optic
transillumination
technique is based on the fact that carious enamel has a
lower index of light transmission than sound enamel.The
light is absorbed more when the demineralization process
disrupts the crystalline structure of enamel and dentin. Soo
this gives that area a more darkened appearance.
84. this method uses a light source , preferably
bright ,to illuminate the tooth. Caries or
demineralized areas in dentin or enamel
show up as darkened areas with this
technique.
This effect can be achieved with a fiber optic
illuminator, which is readily available at the
handpiece coupler of the dental operatory.
85.
86. indications
used for detection of approximal and occlusal
caries
Posterior approximal
caries can be diagnosed
with the light probe
positioned on the
gingiva below the cervical margin of the tooth,
whereby the light passes through the tooth
structures and approximal decay produces a dark
shadow on the occlusal surface.
87. advantages
This device has the advantage that the
examination is done with an operating light
source already available in general practice,
it is useful for approximal and occlusal lesions
88. Disadvantages
Its sensitivity and specificity are not sufficient
for detection of very early caries.
Besides, it is not quantitative and therefore not
useful as a caries monitor over time.
However, studies on the diagnostic efficacy of
this device present conflicting results.
89. One study compared FOTI with radiographic
examinations for occlusal caries and concluded
that radiographic examinations were a better
diagnostic tool than FOTI.
A contrary result was found in a study conducted
in 1992. According to another study
transillumination exhibited a low sensitivity to
caries detection but showed a high positive
predictive value.
90.
91. In one study in the review of the diagnosis
of pre cavitated lesions using different
diagnostic methods, found the use of
explorer to be the least effective method
for the detection of carious lesions. FOTI
exhibited a better sensitivity than
clinical inspection in detecting pre
cavitated lesions that had a shadow or
opacity underneath the marginal ridge.
92. Another study also reviewed the diagnosis of caries on
proximal surfaces and found that FOTI was superior to
visual inspection and radiography. However in a previous
review radiography was superior to FOTI. A conclusion can
be obtained from some of the previous studies that FOTI is
a cost efficient noninvasive adjunct to a clinical
examination in the detection of posterior dental
caries .
Emerging technologies for diagnosis of dental caries:
The road so far Bennett T. Amaechia Department of Community Dentistry, University
ofTexas Health Science Center at San Antonio,San Antonio,Texas 78229, USA
93. 2. Digital imaging fiber-
optic transillumination
This is a digitized and computed version of the
FOTI. DIFOTI uses white light to transilluminate
each tooth and to instantly create high-
resolution digital images of the tooth.
It is based on the principle that carious tooth tissue
scatters and absorbs more light than
surrounding healthy tissue.
Decay near the imaged surface appears as a darker
area against the more translucent brighter
background of surrounding healthy anatomy.
94.
95. Indications
DIFOTI is used for detection of both
incipient and frank caries in all tooth
surfaces.
DIFOTI can also be used to detect
fractures, cracks, and secondary caries
around restorations.
96. Procedure
A single fiber-optics illuminator in the
mouthpiece delivers light to one of the
tooth’s surfaces.As this light travels through
layers of enamel and dentin,it scatters in all
directions toward the nonilluminated surface
usually the opposite surface.
The light is then directed through the mouthpiece to a
miniature electronic charge coupled device( CCD)
camera in the handpiece.The camera digitally
images the light emerging from either the smooth
surface opposite the illuminated surface or the
occlusal surface.
97. These images are displayed on a computer
monitor in real time and stored on the hard drive
for easy retrieval for comparative review of
images over time. Image acquisition is controlled
with software and a foot pedal.
Images of the teeth can be viewed by both the
clinician and patient, and therefore can be used
for patient education and motivation. It is
important to note that DIFOTI images the light
emerging from surface closest to the CCD
camera. It does not image the tooth material
between the light source and the CCD camera,
and therefore cannot indicate the depth of lesion
penetration.
98.
99. Schneiderman et al.demonstrated a method of
using DIFOTI to quantitatively monitor lesion
progression and reported a successful result.
Inherent with the high sensitivity of the device,
dark areas in DIFOTI images may sometimes
be due to stains or calculi on tooth surface;
therefore it is suggested that prophylaxis
should be carried out prior to the use of the
device in order to increase the specificity.
100. 3. Quantitative light-
induced fluorescence
This is a prominent diagnostic system in dentistry.The
quantitative light-induced fluorescence QLF technology
was introduced in 1995 and was quickly used to monitor
caries lesions over time.
Since then several studies have demonstrated the ability
of the QLF system to detect and monitor caries in real
time, both in children and adults. QLF uses the natural
fluorescence of the teeth, which is determined by the
light absorption and scattering properties of the teeth, to
discriminate between caries and surrounding sound
enamel.
Emerging technologies for diagnosis of dental caries:
The road so far BennettT. Amaechia Department of Community Dentistry,University of
Texas Health Science Center at San Antonio,San Antonio,Texas 78229, USA
101. Furthermore, excessive scattering in carious
tissue prevents the light entering the tissue
from reaching the DEJ and dentin where the
chance of absorption by a fluorophore for
fluorescence remittance is a magnitude
higher. Light entering the sound enamel is
scattered about a factor of 10 less than in
carious enamel,so photons travel further in
sound enamel and may reach dentin and
along their path may be absorbed by a
fluorophore leading to excitation of
fluorescent photons.
102.
103. The auto fluorescence of tooth tissue decreases
with demineralization and QLF measures the
percentage fluorescence change in demineralized
enamel with respect to surrounding sound enamel
and relates it to the amount of mineral lost during
demineralization. Caries lesions appear dark when
viewed with QLF, and this is based on the principle
that a demineralized tissue limits the penetration
of light due to excessive scattering of photons
entering the lesion with consequent limitation to
the chance of a photon being absorbed and
fluorescence remitted.
104. Hence, a caries lesion is observed as a
dark spot surrounded by highly
luminescent sound enamel.The QLF
system comprised of a special intraoral
camera device connected to a computer
Electronic Systems. To visualize and
capture the tooth surface image, white
light is filtered through a blue-
transmitting bandpass filter.
105. with peak intensity of =370 nm and bandwidth of
80 nm to provide illumination of the tooth
surface with a blue-violet light with an intensity
of 13 mW/cm2.A dental mirror provided
uniform illumination of the tooth surface, and
with the aid of a color CCD sensor .The
Netherlands positioned in front of it to filter
out all reflected and back-scattered light, the
fluorescent image of the tooth surface is
recorded and digitized by the frame grabber to
be available for quantitative analysis using the
QLF software.Once the fluorescent image of
the tooth is captured and recorded by the PC,
106. analysis of the lesion can be initiated by a
user-defined patch with borders placed on
sound enamel surrounding the lesion.The
sound fluorescence radiance values inside the
patch are reconstructed through two-
dimensional linear interpolation of sound
enamel values on the patch borders.The
decrease in fluorescence was determined by
calculating the percentage of difference
between the actual and the reconstructed
fluorescence surface. Any area with a drop in
fluorescence radiance of more than 5% is
considered to be a lesion
107. The QLF software automatically gives the
value for the percentage of fluorescence
radiance loss percent and simultaneously
data storage.Several advantages in the
practicality of use and accuracy in
quantifying demineralization have been
reported. It uses ordinary white light
sources, which are an advantage over
ionizing radiation of x ray.
108. advantages
The main advantages of QLF are the
following:
1 the increased contrast between carious
and sound enamel makes earlier and faster
for detection of lesions possible and
2 the examination presents no danger to
patient or operator, since the excitation
light is white light and of relatively low
intensity.
109. This method has been used to monitor
demineralization in vitro, to assess incipient
lesion remineralization in situ, to assess
demineralization in vivo, and to
quantitatively monitor tooth whitening.
110. Several studies used QLF in orthodontic
patients for longitudinal studies of white spot
lesions around brackets. A multicenter study
used QLF to monitor caries development in
127 children aged 9–12 yr for 12 months and
reported sensitivity of 77% and specificity of
71% for detection of occlusal lesions and
sensitivity and specificity of 79% and 75%,
respectively, for detection of smooth surface
lesions.
111. Visual clinical examination in this study scored
sensitivity of 38% and specificity of 79% for
occlusal surface lesions. Many other
applications have been reported for early
diagnosis and quantification of mineral loss
using the QLF method such as detection of
recurrent caries around restorations,
detection of occlusal caries, and in fluoride
studies.The QLF technique has been
validated , the in vitro gold standard, in both
permanent and deciduous teeth showing
excellent correlations.
112. When compared to DIAGNOdent,QLF was
found to have a better correlation with changes
in mineral content on smooth surface caries.
Moreover, the repeatability and reproducibility
of QLF have been tested in vivo with the results
showing intraclass correlation coefficients of 0.93–
0.99 and the inter examiner reliabilities between
0.95 and 0.99. Although high sensitivity was
reported, this system has a low specificity in that
it cannot
113. distinguish between caries, stains on tooth
surface, and white spot due to developmental
anomalies such as fluorosis.
Recent development in QLF incorporates a red
fluorescence detector; excitation of red
extrinsic fluorophores from bacterial
metabolites porphyrins by blue light causes
plaque/ calculus/bacterially infected caries
lesions to appear red on a bright green
background, enabling the use of QLF to
quantify and monitor plaque.
114. 4. DIAGNOdent laser system
This is a laser fluorescence system that detects
changes in the tooth structure due to
demineralization.These structural changes
cause an increase in the fluorescence at specific
excitation wavelengths.The intensity of the
fluorescence depends upon the wavelength of
the light as well as the structure and condition of
hard dentinal tissues. DIAGNOdent with a laser
diode that generates a pulsed 655 nm laser beam
via a central fiber is transported to the tip of the
device and into the tooth.
115. When the incident light interacts with tooth
substance, it stimulates fluorescent or
luminescent light at longer Stokes shifted
wavelengths.The intensity of fluorescence is
a function of the degree of demineralization
or bacterial concentration in the probed
region.
117. Mode of action
In fact, the full fluorescence mechanisms of the
DIAGNOdent is still only partly understood.
There are two theories regarding its mode of
action.
The first theory is that when the red incident light
meets a change in tooth tissue porosity due to
demineralization , it stimulates fluorescent light
of a different wavelength.This generated
fluorescent light travels through additional light
fibers that are concentrically arranged around
the central fiber a filter eliminates ambient light
into a microprocessor,
118. which analyses and translates the signal
into an acoustic signal and a digital display
of numerical figures which shows both a
real-time and a maximum value, ranging
from 0–99.9, which can be used in the
diagnostic protocol.
119. The second theory is that DIAGNOdent
responds to the fluorescence emitted from
the metabolites of cariogenic bacteria ,i.e., it
is measuring the level of cariogenic bacterial
activity in terms of metabolites.The
DIAGNO-dent operates on the premise that a
high level bacteria reading indicates a
probability of having a decalcified enamel
structure. Hence, one weakness of this
technology is that all bacteria, not only
caries-related bacteria, produce fluorescence.
120. Advantages
A lot of organic and nonorganic materials such as
stains, plaque and calculus ,some prophy paste,
food, and even the tooth itself can cause
fluorescence. In any case, one of the advantages of
the system is that the quantitative nature of its
readings gives a basic guideline as when to
intervene.
Decay in a patient can be followed longitudinally to
monitor the extent of the decay at every recall
It was concluded in an in vitro study that this laser
device had a higher diagnostic validity than the
electrical caries monitor (ECM) and may be a
valuable tool in the longitudinal monitoring of caries
and in assessing the outcome of preventive
interventions.
121. Disadvantages
However, it is pertinent to mention that other
studies have shown and it has been
acknowledged by the developers of
DIAGNOdent that factors such as the presence
of bacterial plaque, dental prophylactic pastes,
fissure sealants, and composite resin materials
give false positive readings with this instrument.
Emerging technologies for diagnosis of dental caries:
The road so far BennettT. Amaechia Department of Community Dentistry,University ofTexas
Health ScienceCenter at San Antonio,SanAntonio,Texas 78229,USA
122. 5 Electrical caries monitor
This technology is based on the electrical
conductivity differences between sound and
carious dental tissues.
ECM is based on the principle that electrical
conductivity is a function of porosity. Enamel
demineralization results to increased porosity of
the enamel tissue and saliva fills the pores and
forms conductive pathways for electrical
transmission. Since saliva is a better electrical
conductor than enamel tissue, the conductivity
increases with demineralization.
123. On this basis, ECM measures the electrical
resistance of a site on the tooth during
controlled drying. By drying the tooth
surface, the resistance is determined by
the tooth structure, avoiding electrical
conductance by surface liquid saliva.
124. High measurements indicate well-mineralized
tissue while low values indicate demineralized
tissue.The electrical conductivity of a tooth
changes with demineralization even when the
surface remains macroscopically intact. Example
of this device is the lode electronic caries
monitor. Conductivity is measured from the
probe tip in the fissure through the dental pulp
to a handheld earth lead with the patient
forming part of the circuit.
125. advantage
A major advantage of the ECM is to present
objective readings, which have the potential
for monitoring lesion progression, arrest, or
remineralization.The sensitivity and the
specificity of this machine have been
reported to be very high, 0.75 and 0.77,
respectively, when used to detect occlusal
caries in vivo and ex vivo,indicating that it is
a valid indicator for detecting the presence
or absence of lesion porosity.
126. A strong relationship between both lesion
depth and mineral content in enamel has
been shown with ECM readings.The only
drawback is the fact that it is time consuming
to use in a routine full-mouth examination.
Emerging technologies for diagnosis of dental caries:
The road so far BennettT.Amaechia Department of Community Dentistry, University ofTexas Health
Science Center at San Antonio,San Antonio,Texas 78229, USA
127. 6. Midwest Caries I.D.
The Midwest Caries I.D. detects differences of
optical behavior inside the tooth related to
change in the tooth structure and it is
therefore not sensitive to bacterial content.
The Midwest Caries I.D. uses infrared and red
light emitting diodes (LEDs) and a fiber optic
to distribute light to the observed area
present at the probe tip.
A second fiber optic collects light from the
observed area to a photodetector that
measures returned collected light.This
photodetector then transmits the signal to a
microprocessor that compares signal levels
with defined parameters.
128. When the result is positive, the processor
deactivates the third green LED and pulses at
a higher intensity than the red LED.
When the detection is negative i.e., healthy
tooth area, the green LED is dominant
resulting in a green illumination when healthy
structure is detected and red illumination
when caries are detected.
129. A buzzer also beeps with different frequencies to
indicate the intensity of demineralization detected.
The Midwest Caries I.D. can be used for approximal
caries detection during the examination by slightly
angling and moving the probe along the marginal
ridge just over the vulnerable approximal area.
This approach seems much more convenient than
the DIAGNOdent approach since it enables minimal
dilution of the light signal from all surrounding
structures which is the case for transillumination by
sending and capturing the light signal.
Emerging technologies for diagnosis of dental caries:The road so far
BennettT.
130. 7. Polarization-sensitive
optical coherence
tomography
While all the above technologies use only the alteration
of fluorescence, reflectance, electrical conductance, or
impedance
properties of enamel with demineralization to monitor
changes in caries lesion over time, optical coherence
tomography OCT can additionally produce an image
of tissue microstructure of the caries lesion to show
the changes within, and therefore can be compared
both qualitatively and quantitatively with
histological methods such as microcomputed
tomography and transverse microradiography, the
current gold standard for measuring
demineralization.
131. OCT technology is an imaging modality that
provides a tool for noninvasive evaluation of
tissue microstructure by providing high spatial
resolution 10–20 um and real-time, two
dimensional depth visualization.The principle of
OCT is similar to B-mode ultrasound imaging,
except that OCT uses near infrared ( NIR) light
instead of sound.
First demonstrated ,OCT creates a two-
dimensional map of the tissue microstructure by
illuminating the tissue with low power NIR light,
collecting the backscattered light, and analyzing
the intensity.OCT is based on confocal
microscopy and low coherence interferometry.
132. principle
Based on the principle that the highest quality
image information is contained in the portion of
the detected light that is relatively unscattered
and therefore travels the most direct path
through the tissue, OCT uses low coherence
interferometry to selectively remove the
component of backscattered signal that has
been multiply scattered, resulting in very high
resolution images. Although the first application
of low coherence interferometry in the
biomedical optics field was for the measurement
of the eye, since then OCT has been used to
provide images of tooth structures.
133. Following the modification of the system to
produce polarization-sensitive OCT PS-OCT,
the application of OCT in dentistry has
widened covering in vitro images of dental
caries. However, most reports refer to
longitudinal OCT imaging only. Recently
Amaechi and co-workers used a combination
of PS-OCT technology with confocal
microscopy developed initially forretina
imaging to further the application of the OCT
into dental tissue imaging.This combined
system can operate in
134. different regimes to deliverA scans, B scans
longitudinal images, andC scans or transverse
images.The confocal image, which can be
displayed sideways, along with the en face OCT
image at each depth, was useful in identifying
the caries lesion and aligning the tooth.
This was especially useful for the in vivo
application of the system. Using this system,
they demonstrated the ability of OCT to
quantitatively and qualitatively detect and
monitor incipient enamel and root caries as
early as 24 h in its development.
135. OCT was able to discriminate between sound
and demineralized carious tooth tissue by the
differences in reflectivity. Other studies
examined the influence on OCT imaging of
factors such as lesion staining, ambient lighting,
and the presence of saliva or bacterial plaque,
136. which have been identified to adversely affect other
technologies, especially those based on tooth tissue
fluorescence, and reported that these factors do not
influence OCT imaging and measurements
The use of A scan from OCT imaging to produce
quantitative data relating to the degree of change in
reflectivity, and hence the degree of change in
mineral level, of the tooth tissue following
development of caries was also demonstrated in one
study.
Emerging technologies for diagnosis of dental caries:The road so far
BennettT.
137. 8. Caries Scan
This device is based on the proven technology of
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.The
frequency domain is based on a sinusoidal signal
applied to a sample at known amplitude and
frequency.
The response waveform is then measured and the
impedance calculated by a transfer function
relationship of the applied voltage perturbation
and acquired response current.
138. It is the first dental diagnostic tool to use ac
impedance spectroscopy to quantify dental
caries early enough to enhance preventive
treatment
According to the originators, the CarieScan is
not affected by optical factors such as
staining or discoloration of the tooth; it
provides a qualitative value based on the
disease state rather than the optical
properties of the tooth.
139. Indication
The device is indicated for the detection,
diagnosis, and monitoring of primary coronal
dental caries occlusal and accessible smooth
surfaces, which are not clearly visible to the
human eye.
140. Contraindication
It cannot be used to assess secondary caries,
the integrity of a restoration, dental root
caries, and the depth of an excavation within
a cavity preparation.
141. ..This device uses disposable tufted sensors for single
use and a test sensor nondisposable , which is used
to test the device and confirm if the system is
operating correctly.
For assessment of caries, while tufted sensor brush
contacts the tooth surface being examined, a soft
tissue contact, which is a disposable metal clip that is
placed over the lip in the corner of the patient’s
mouth, connects to the CariesScan via a soft tissue
cable to complete the circuit.
During measurement, a green color display indicates
sound tooth tissue, while a red color indicates deep
caries requiring operative, and a yellow color
associated with a range of numerical figures from 1
to 99 depicts varying severity of caries, which require
only preventive care.
142. Accompanying the CarieScan is the CarieScan-Plus, which is a
wirelessly linked control system designed to be used as a patient
management system, allowing data to be automatically
captured, filed, and recalled electronically on a by tooth, by-
surface, by-date basis for dental health monitoring.
This enhances communication with the patient as an aid to
preventive motivation and caries control. A systematic
review comparing CarieScan with clinical visual examination,
bitewing radiograph, and DIAGNOdent reported CarieScan
to have a superior sensitivity and specificity both 92.5% over
other methods.
Emerging technologies for diagnosis of dental caries:
The road so far BennettT. Amaechia Department of Community Dentistry, University ofTexas Health Science Center at
San Antonio,San Antonio,Texas 78229,USA
143. 9. Frequency-domain infrared
photo thermal radiometry and
modulated luminescence
Although still under development, the most
recent technology in the field of caries
diagnosis is the combined frequency-domain
laser-induced infrared photothermal
radiometry and modulated luminescence
PTR/LUM.
144. Advantages
Some of the inherent advantages of the
adaptation of PTR to dental diagnosis in
conjunction with LUM emission as the dual
probe technique have been reported in recent
literature.
145. The PTR technique is based on the modulated
thermal infrared blackbody or Planck radiation
response of a medium, resulting from optical
radiation absorption from a low intensity laser
beam (mW) and optical-to-thermal energy
conversion followed by modulated temperature
rise( “thermal waves”) usually less than 1 °C in
magnitude.The generated signals from
PTR/LUM instrument carry subsurface
information in the form of a spatially damped
temperature depth integral.Thus, PTR has
depth-profilometric ability: it can penetrate and
yield information about an opaque or highly
scattering medium well beyond the range of
optical imaging.
146. The laser-intensity modulation-frequency
dependence of the penetration depth of
thermal waves makes it possible to perform
depth profiling of materials. In PTR
applications to dental hard tissue, optical and
thermophysical material properties and
depth information are obtained in two
distinct superposed modes: conductively,
from nearsurface distances (5–500u m)
controlled by the thermal diffusivity of
enamel and the modulation frequency of
147. The laser beam intensity, and radiatively,
through midinfrared blackbody emissions
from considerably deeper regions
commensurate with the optical extinction
penetration depth of the diffusely scattered
laser optical field, a diffuse photondensity
wave several millimeters.Owing to its
depthintegral nature, the PTR signal consists
of both surface and subsurface responses of
dental tissue and as such it is expected that it
can distinguish between caries, stains on
tooth surface, and developmental white
spots
148. unlike the fluorescence device such as
QLF.The radiative mode operates through
emission of midinfrared blackbody photons
that undergo much reduced scattering than
the NIR source photons due to their much
longer wavelength.
149. These IR photons exit the dental tissue
through spectral windows of relative
transparency in enamel Fluorescence
techniques monitor radiative emission
variations between optically excited healthy
and carious dental fluorophores and have
been the mechanism behind the
commercially available DIAGNOdent
instrument.
150. .The most fundamental difference lies in the fact
that PTR/LUM is a depth profilometric
technique, whereas DIAGNOdent and all other
photonics-based technologies to date are not.
PTR/LUM is sensitive to changes in both optical
and thermal properties of the sample with zero
PTR signal baseline unless there is optical
absorption on the surface or in the bulk of the
solid, whereas the DIAGNOdent only senses
differences in optical properties through dc
fluorescence changes and in the presence of a
significant signal baseline even under conditions
of healthy enamel.
151. These differences render the combination of
PTR and LUM techniques to have the highest
signal dynamic range in detecting very early
demineralization and thus predictably yield
the best diagnostic results in caries diagnosis.
152. The introduction of modulated dynamic
fluorescence( “luminescence”) revealed the
existence of two relaxation lifetimes
originating in the hydroxyapatite
composition of dental enamel.Variations in
LUM emission fluxes and lifetimes between
healthy and carious enamel were shown to
have a limited depth-profilometric character.
A combination of PTR and LUM has been
developed into an analytical caries diagnostic
tool of combined specificity and selectivity,
substantially better than the DIAGNOdent,
radiographic, and visual methodologies.
153. The combined technique and instruments PTR
and LUM outputs four signal channels
simultaneously: amplitudes and phases of
photothermal and luminescence waves
generated in response to harmonic laser source
excitation. A study that compared the caries
diagnostic ability of PTR/LUM, DIAGNOdent,
visual inspection, and radiographs with
histological technique as the gold standard
showed that the combined PTR/LUM method is
superior to all other tested methodologies with
sensitivity of 81%/ 79% and specificity of
87%/72% for caries level of enamel and dentin,
respectively. Combining PTR and LUM showed a
superior sensitivity and specificity over either
PTR or LUM alone.
154. In a second study, the authors used a 670 nm,
450mW laser at 30 Hz to examine approximal
caries and demonstrated PTR to have the
potential to be a reliable noninvasive tool for the
detection of early approximal demineralized
lesions, which cannot be detected by
conventional bitewing radiography.
Emerging technologies for diagnosis of dental caries:
The road so far BennettT. Amaechia Department of Community Dentistry,
University ofTexas Health Science Center at San Antonio,San Antonio,Texas
78229,USA
155.
156. 10. Cone beam computed
tomography
The application of cone beam computed
tomography (CBCT) in dental caries diagnosis
has not been widely studied.
The first and only study that compared caries
diagnosis ability of two CBCT systems,
NewTom 3G Quantitative Radiology and 3DX
Accuitomo, and two intraoral
modalities,Digora-fmx and film , with
histological technique serving as the
validation standard concluded that.
157. the NewTom 3G CBCT had a lower diagnostic
accuracy for detection of caries lesions than
intraoral modalities and the 3DX Accuitomo
CBCT.The Accuitomo CBCT had a higher
sensitivity than the intraoral systems for
detection of lesions in dentin, but the overall
true score was not higher.
158. The investigation to apply in caries diagnosis
stems from its numerous advantages when
compared to all current forms of x-ray
imaging. CBCT utilizes the least amount of
radiation to obtain a diagnostic image while
remaining cost effective for patients. By
comparison, the NewTom 3G generates an
average CBCT study using 12.0 uSv.
159. This radiation dose is similar to a quarter panoramic
image or five dental x rays using high-speed film.
Because less radiation means less exposure time, the
complete cycle to make one slice by the NewTom 3G
takes 36s, while the actual exposure time to the
patient is 5.6 s. By comparison, a panoramic image
requires 20–100 Sv. CBCT scanners are more
accurate than dental periapical films or panoramic x
rays.While there is clearly less radiation used to
generate a panoramic image, the amount of
information it renders is less accurate and not as
useful when compared to the three-dimensional
images of a CBCT scan.
160. Emerging technologies for diagnosis of
dental caries:
The road so far BennettT. Amaechia
Department of Community Dentistry,
University ofTexas Health ScienceCenter at
San Antonio,San Antonio,Texas 78229, USA