showed a trendp = 0.0003
The IRC reflection parameters and FSRTF during demineralization showed a trend of decrease (IRC: R = 0.95; p = 0.0003, FSRTF: R = 0.76; p = 0.0286), while the backscattering parameter AIB increased (R = 0.81; p = 0.0148) and FSAB showed an oscillatory behavior with no defined trend (R = 0.23; p = 0.5837), as shown in Fig. 2 .