CARIES DETECTION
Caries Definition
Dental caries, a chronic disease is unique among human and is one of the most common
important global oral health problems in the world today. It is the destruction of dental hard acellular
tissue by acidic by-products from the bacterial fermentation of dietary carbohydrates especially sucrose. It
progresses slowly in most of the people which results from an ecological imbalance in the equilibrium
between tooth minerals and oral biofilms which is characterised by microbial activity, resulting in
fluctuations in plaque pH due to bacterial acid production, buffering action from saliva and the
surrounding tooth structure. The microbial community of caries is diverse and contains many facultatively
and obligately-anaerobic bacteria. S. mutans is the most primary associated with it
Classification of dental caries
International Caries Detection and Assessment System Severity Codes
G.V.BLACKS CLASSIFICATION
• Class I cavities- All pit and fissure cavities i.e.cavities on occlusal surface of
premolars and molars,cavities on occlusal two thirds of the facial and lingual
surfaces of molars,cavities on lingual surface of maxillary incisors.
• Class II cavities- Cavities on the surface of proximal surfaces of posterior teeth.
• Class III cavities - On the proximal surfaces of anterior teeth that do
not involve the incisal angle.
• Class IV cavities- On the proximal surfaces of anterior teeth that do involve the
incisal edge.
• Class V cavities- On the gingival third of the facial or lingual surfaces of all teeth.
• Class VI cavities- On the incisal edge of anterior teeth or occlusal cusp heights of
posterior teeth.
Etiology of Dental Caries
1. Microflora: acidogenic bacteria that colonize the tooth surface.
2 Host: quantity and quality of saliva, the quality of tooth etc.
3. Diet: intake of fermentable carbohydrates, especially sucrose, but also starch.
4. Time: total exposure time to inorganic acids produced by the bacteria of the dental
plaque.
Diagnosis in a dental caries perspective
Caries lesions can be diagnosed or perhaps more correctly, classified to be able:
• to achieve the best health outcome for the patient by classifying caries
lesions corresponding to the best management options for each lesion type
• to inform the patient. The patient is central to the management of the carious
process. It is the patient who will control the process, not the dental professional.
The dentist’s role is to inform the patient of the diagnosis and prognosis, and
whether any action is required. If the dentist does not share the diagnosis with the
patients and inform them of their crucial role for the control and management of
their caries lesions, this may lead to disappointment at best or legal action at
worst.
• to monitor the clinical course of the disease. Once it has been decided to
intervene with an active caries lesion the dentist should monitor the fate of the
lesion over time and record any changes in surface integrity and activity status.
An active lesion that converts into an inactive lesion or regresses to a sound
surface is considered a positive outcome. Active lesions that remain active most
often reflect a lack of compliance. Alternatively, it should be considered whether
the chosen intervention is suitable.
CARIES DETECTION METHODS
Visual–tactile caries examination: a systematic clinical approach
The clinical caries examination should be carried out in a systematic manner after each
quadrant of the mouth has been isolated with cotton rolls and a suction device to prevent
saliva from wetting the teeth once they have been dried
Good lighting and clean, dry teeth.
o Thorough drying is performed with a gentle blast of air from a three-in-one
syringe. An initial non-cavitated enamel lesion is more easily disclosed when the
tooth is dry, since the difference in the refractive index between carious and sound
enamel is greater when water is removed from the porous tissue.
o The teeth are examined by the aid of a dental mouth mirror and a sharp probe.
The mouth mirror is used to displace the cheeks and lips and to facilitate vision in
difficult to reach areas on the teeth. Reflected light from the mouth mirror can be
applied to search for dark shadows,which may be suggestive of dentinal lesions.
o Transmitted light from the operating lamp is particularly helpful for examining
the approximal surfaces of anterior teeth
o However, even if direct access to an approximal surface is limited, careful
inspection may reveal a non-cavitated lesion that extends onto the buccal or
lingual surfaces
Sensible use of the probe
o If the teeth are heavily covered by plaque, it may be necessary to clean the
dentition before a proper caries diagnosis can be performed (Fig. 4.24a, b)
o In any case,for plaque-removal purposes as well as for assessment of surface
roughness the use of a sharp metal probe is recommended.
o The probe serves two purposes:
first, to remove the biofilm (using the side of the probe) to check for signs
of demineralization and surface break and,
secondly, to ‘feel’ the surface texture of a lesion, as sensed through minute
vibrations of the instrument by the supporting fingers when moving the tip
of the probe at an angle of 20–40 degrees across the surface (Fig.4.25).
o Forceful poking with the probe perpendicular to the lesion should be avoided in
order not to cause irreversible damage to the surface of the lesion.
Additional aids in visual–tactile caries diagnosis
o Fiber-optic transillumination
Fiber-optic transillumination (FOTI) is a diagnostic method by which
visible light is transmitted through the tooth from an intense light source, e.g.
from a fine probe with an exit diameter of 0.3–0.5 mm. If the transmitted light
reveals a shadow when the tooth is observed from the occlusal surface this may be
associated with the presence of a carious lesion. If the transmitted light reveals a
shadow when the tooth is observed from the occlusal surface this may be
associated with the presence of a carious lesion.
For optimal performance the probe should be brought in from the buccal
or lingual aspect at an angle of about 45 degrees to the approximal surfaces
pointing apically, while looking for dark shadows in the enamel or dentin
(Fig.4.27).Shadows are best noticed when the office light is switched off.
Although transillumination is a simple, fast and cheap supplementary
method well known to most practitioners for diagnosing approximal caries in the
anterior teeth , the fiber-optic method has never become broadly accepted for
detection of lesions in approximal surfaces in the premolar and molar regions.
One of the reasons for this may be that the sensitivity of the method is rather low
when using radiography as the gold standard.
o Tooth separation
It is anticipated that the presence of a cavity, if not interfered with,
increases the rate of progression of a caries lesion. Neither radiographs nor FOTI
can help to identify the presence of a cavity on contacting approximal surfaces.
Therefore, other methods such as tooth separation have been introduced. With this
technique orthodontic elastic separators are applied for 2–3 days around the
contact areas of surfaces to be diagnosed,after which access to inspection and
probing is improved.
However, accessibility for inspection after tooth separation is not always
improved as much as needed, and the use of the technique may create some discomfort,
especially in patients with established dentitions.
Laser Light
Diagnodent
DIAGNOdent is a tool that is used after having a cleaning done or during your
dental exam. The technology uses fluorescence to identify areas where
decay is present. Healthy teeth will produce little to no fluorescence while
decayed areas will fluoresce. Because of the high-quality technology being used
as well as its safe nature, DIAGNOdent is ideal for patients of varying needs and
health conditions.
Why Might it Be Used?
There are many reasons why DIAGNOdent might be used to help in the
diagnosis of cavities. Some of these reasons may include:
DIAGNOdent is ideal for detecting early signs of decay
DIAGNOdent is essential for hard-to-reach areas where decay may go
unnoticed
DIAGNOdent is safe to use on all patients, including those who are
pregnant or immune compromised
DIAGNOdent can work in conjunction with x-rays and a physical check for
a comprehensive exam
Electric Current
Electrical conductance measurement
Electrochemical machining (ECM) is based on the principle that a demineralized
tooth has more pores filled with wateror 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.[4] This technique has two methods of application.
Site-specific
Applies probe as electrode into fissures and the electrical conductance of that site
is measured. To prevent current from leaking through superficial layer of moisture
through the gingival, airflow is applied to dry the tooth surface around the probe.
Disadvantage is that only small areas of occlusal surface can be measured at one
time [Figure 12].
Surface-specific
This technique measures the entire occlusal surface, which is covered with an
electrolyte-containing medium where the electrode is placed. ECM uses a fixed
frequency of 23 Hz alternate current [Figure 13].[14] Two instruments based on
the difference in electrical conductance of carious and sound enamel were
developed.
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.
N. Pitts. 2009. Detection, Assessment, Diagnosis and Monitoring of Caries. Swithzerland; .
Karger
