Intensity vs. time curves for the two lesions shown in Figs. 3 & 4 are
plotted in Fig. 5 for both the benchtop and handpiece systems. The
active lesion exhibits a measurable delay before the rapid sigmoidal
rise in intensity that reaches the maximum intensity in only 12 seconds
for the benchtop system and is even faster for the handpiece where it
takes about 8 seconds to peak. In contrast the arrested lesion exhibits
no discernable delay. The intensity slowly rises and does not achieve
peak
intensity after 60 seconds. Mean ± sd of delay, ΔI%,
%Ifin, and rate after 60 seconds of drying for the
active (n=10) and arrested (n=10) lesion areas are tabulated in Table I
for both the benchtop and handpiece systems. The significance level
calculated from unpaired two-tailed t-tests between the active and
arrested groups for each system is also listed. The means of delay,
%Ifin, and rate were significantly
different
between active and arrested lesions for both the benchtop system and the
handpiece. Active lesions had a significantly higher mean ΔI% than
arrested lesions for the benchtop system while there was no significant
difference between the two groups with the handpiece. 3D scatterplots of
delay, %Ifin, and rate for the
active
lesions (red) and arrested lesions (blue) are shown in Fig. 6 for the
benchtop and handpiece systems. There is clear separation in grouping in
the 3D plots between the active and arrested lesions for both systems.
Differentials in the magnitude of the means between active and arrested
lesions for delay, %Ifin, and rate all exceeded ratios
of 5 to 1 with rate being the highest at 9 to 1.