3. Results
An example of acquired intensity vs time curves using the new probe for
sound and lesion areas is shown in Fig. 1F. The active lesion is located
in a very deep narrow fissure as can be seen in the microCT images shown
in Figs. 1C&D. Even though the fissure is very deep the new probe was
effective in dehydrating the active lesion within 20-30 seconds. There
was an initial delay of 7 seconds before the rapid sigmoidal rise in
intensity that is typical of active lesions. The magnitude of
ΔIdrying for the new probe vs the old reflectance probe
for the 6 active and arrested lesions was more than 100 times higher.
Examples of images before and after drying acquired with the benchtop
and handpiece systems are shown Figs. 3 & 4. In Fig. 3 an active lesion
in a pit is shown. The color image in Fig. 3A indicates that the lesion
is only slightly pigmented. The microCT image in Fig. 3B shows a narrow
lesion only halfway through the enamel. The line profile of density vs
position extracted at the position of the yellow line shows a surface
zone of higher mineral content at the position of the red arrow with a
mineral density that peaks at less than 2.5 g/cm3 and
is not highly mineralized. The mineral density at the position of the
green arrow appears sound and approaches 3.0 g/cm3.
SWIR images acquired before and after drying are shown in Figs. 3C-F.
The lesion area shows a dramatic change in intensity before and after
drying for both the benchtop system and the handpiece.