dynamic processes of demineralization and
remineralization of the teeth and in its initial stages
it can be halted. Enamel demineralization is a daily
process that does not necessarily lead to caries.
Early intervention can turn an active lesion into
an inactive one. If the degree of demineralization
does not exceed a certain point, the process may
come to a standstill, even if the enamel surface has
been minimally affected. The conversion of a lesion
from active to inactive requires early diagnosis
and careful monitoring, in order to minimize the
restorative intervention. 6 From this point of view,
modern caries detection means should permit
monitoring of the caries process before the early
lesion progresses to an extensive cavity.
The main objective of this paper is to give an
overview of the use and utility of the two available
caries detection devices of the occlusal surfaces of
the permanent dentition, DIAGNOdent (DD) and
DIAGNOdent Pen (DDPen) (KaVo Dental GmbH,
Biberach/Riβ, Germany), whose function is based
on the fluorescence laser beam.
2. The criteria for the evaluation of caries
diagnostic means
The criteria used for the diagnostic evaluation of
caries are expressed through specific indicators
which are defined in numerical scales and form
the diagnostic accuracy of a test. Specificity and
sensitivity are the two dimensions, widely used
for the description and quantification of several
diagnostic techniques. Specificity refers to the
correct identification of the healthy dental tissues,
while sensitivity refers to the correct identification
of caries. The above indicators are expressed as
values between 0 and 1 (100%). As these values
approach 1, the qualitative effect is higher and they
should be at least 0.75 for sensitivity and above 0.85
for specificity. 7 Methods with low sensitivity can
lead to suboptimal treatment, whereas methods
with low specificity, to overtreatment. The caries
detection methods with low sensitivity should be
combined with techniques that are distinguished
by high specificity and vice versa.
The accuracy of a method in most studies occurs
from the sensitivity and specificity values and is
often described by the area below the ROC curve
(Receiver Operating Characteristics). The accuracy
of the sum of the measurements obtained in
a procedure is called reliability or otherwise
repeatability and has a key role in the effectiveness
of the procedure.
2.1. Conventional caries diagnostic means
In everyday clinical practice, direct visual
observation is the most established method of
tooth decay detection as it is easy and inexpensive.
This method is mainly based on the subjective
interpretation during visual examination and is
often combined with radiographs and tactile
examination with a metal probe. 8
Many studies indicate that visual observation is
characterized by lower sensitivity in relation to
specificity with the latter exceeding 0.85 for caries
Stomatology Edu Journal
diagnosis in occlusal surfaces. 9,10,11 Lussi et al. 12 , in
an vitro study, showed that the sensitivity of visual
observation as a diagnostic method becomes
double in case of dentine caries (0.62) when
compared to that of enamel (0.31). Gimenez et
al. 13 in a systematic review report that publications
in respect to the accuracy of optical observation as
a ‘diagnostic instrument’ do not exhibit sufficient
qualitative methodology as far as the selection of
the samples is concerned. They also underline that
visual observation constitutes a reliable a clinical
caries detection method. In another systematic
review, Bader et al. 14 mention that the optical
observation displays high specificity, but low
efficiency for sensitivity and repeatability.
As compared to the above laboratory studies,
clinical studies report higher specificity than
sensitivity in response to visual observation. 15
The difficulty with the clinical studies is the lack of
proper identification of the healthy dental tissues
by the devices due to the frequent presence
of dental calculus, bacterial plaque, saliva and
food remnants. The use of established optical
calibration systems such as ICDASII or Ekstrand’s
criteria seems to contribute to a more accurate
caries detection system, given the fact that they
provide guidelines and a rational quantification of
lesions. 15 The combined use of visual observation
and tactile sensation with the use of metal probe
does not appear to significantly improve the
diagnostic capability of direct visual observation.
Agnes et al. emphasize the possibility of damaging
the adjacent tooth with the sharp edge of the
probe. 16 On the other hand, the visual observation
assisted by loops of 1,5X to 4,5X shows increased
detection sensitivity. 17
Bitewing radiographs are a useful means of
detecting interproximal caries; however, their
advantage is quite limited to occlusal carious
lesions, due to the overlay phenomenon. 18
Furthermore, 40-60% of the tooth’s metal ions
have to be lost so as the lesion becomes visible
radiographically. This is another reason why the
radiographic imaging is not used clinically for the
detection of incipient caries lesions. 19
Therefore, the most important limitations of
conventional diagnostic tools are their low
sensitivity, specificity and reproducibility, the
difficulty to determine the activity of the lesion
and the inability to monitor its progression. For
all these reasons, either more accurate detection
methods or a combination of the above met