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.