CARIES DETECTION WITH LASER FLUORESCENCE DEVICES. LIMITATIONS OF THEIR USE
The sensitivity of DD can be increased for more
deep caries, with values of 0.66 in D2 and 1 in D3.
Sensitivity for the D1 level was reported at 0.74. 39
3.2. DIAGNOdent Pen Device
The inability of DD to detect approximal caries was
the primary cause of creating the DDPen (Fig.1).
Figure 1. The handpiece of the DDPen.
The DDPen follows the basic principles of the DD
model. The main difference is the design of its tip
which can be rotated to the longitudinal axis and
thus permitting the detection of approximal caries.
Also, DDPen uses the same optical sapphire fiber
for the distribution of radiation and the detection
of tooth fluorescence without the interference of
other optical fibers (Fig. 2).
Figure 2. The DDPen tip over an occlusal surface of a
molar.
Two different tips are available; a cylindrical one
(CYL) with a diameter of 1.1 mm and a conical one
(CON) with a diameter of 0.7mm. Although, the
diameter of the CON is about 0.3mm thinner than
that of DD and thus it would be expected to show
better accuracy on pits and fissures, it seems that
there is no significant difference between them 40
(Fig. 3).
Figure 3. The different tips of the DDPen.
50
3.2.1. Accuracy and repeatability of DDPen
Lussi et al. 40 compared in vitro the accuracy of
caries detection by DD and DDPen. In their study,
o
119 third molars, kept in frozen state at -20 C,
were examined. DDpen showed higher specificity
(0.71 to 0.91) compared to the DD (0.69-0.79), but
relatively lower sensitivity (0.78 to 0.91) against the
latter (0.81 to 0.96).
The main limitation of the study is that only third
of the molars were used, whose occlusal surface
varies considerably in different individuals as
compared to other posterior teeth. Kuhnisch et
al. 41 found that the reproducibility of DD of the
same examiner (0.89) was similar to that of DDPen
(0.88), while between different examiners reliability
(0.86) was noted.
Sinanoglou et al. 42 evaluated in vivo the occlusal
surfaces of 217 permanent molars and premolars,
comparing the visual observation (ICDASII), DDPen
and bitewing radiography.
One week after the first measurements, the patients
were invited for re-examination and 82 teeth were
reassessed with the above-mentioned techniques.
Only the teeth with dentine caries were examined
(64 of 227) and the clinical depth of the lesion was
measured.
The reliability of DDPen was moderate to good,
with AUC 0.55-0.64, but noticeably inferior in
contrast to that of visual observation (AUC 0.71-
0.76) that reached higher specificity values than
sensitivity. At this point, it should be mentioned that
the results of the evaluation for visual observation
could have been affected by the subjective skills
and the level of the examiner’s acquaintance with
the device. 15
Moreover, the device detection capability was
better for dentin caries (D3), a finding supported
by many other studies. 14,15,43 The reproducibility for
DDPen between different examiners (0.61, 0.65)
and the same one (0.59. 0.65) was relatively low
(16.42).
It is worth noting that in the study by Seremidi
et al. 17 the teeth were stored in tap water for a
long time, which is likely to have an impact on the
fluorescence levels of the teeth.
The study by Achilleos et al. 43 revealed low
sensitivity values (0.66-0.75) for DDPen, which
may be attributed to the fact that the study was
focused on the D1 level, where the performance
of this device is reduced compared to the D3
level. Additionally, the relatively small number of
samples 38 and the only one week period among
the two measurements were reported as limitations
of this study.
Mortensen et al., 44 focusing on the level of D3,
showed high repeatability for DDPen between
different examiners (0.98). For COV=40, there
was a very high specificity (0.97) but very low
sensitivity (0.07). The authors support the idea that
if the manufacturer’s COV are applied in clinical
practice, there will be a significant reduction of
overtreatment, but also the detection of caries in
D3 will be very low.
Stoma Edu J. 2017;4(1): 46-53. http://www.stomaeduj.com