Abstract
Enamel components are related to enamel caries susceptibility, thus, non-destructive techniques to be used in selecting homogeneous dental enamel have been studied. This study aimed to determine the enamel components that make it more susceptible to in vitro demineralization. Fourier transform Raman Spectroscopy (FTRS) was used to verify the relative amounts of organic material and enamel mineral before and after being submitted to an 8-day pH cycling model. FTRS was performed in 30 enamel slabs, which were subsequently demineralized; next, the slabs were again analyzed by FTRS. The cross-section microhardness was performed for mineral loss (ΔZ) quantification. Slabs that presented the greatest differences in the caries development pattern, considering the ΔZ mean obtained (ΔZ=1,510.1±623.4; n=30), were selected in order to constitute 2 groups with statistically different ΔZ values, more demineralized group (MDG) and less demineralized group (LDG), which had ΔZ=2,368.9±421.7a and ΔZ=909.2±229.2b (n=8), respectively. The differences between both MDG and LDG, regarding enamel components (phosphate, carbonate and organic matrix) determined by FTRS before and after pHC, were accessed by t test (significance level=0.05). The results showed that all groups presented fewer carbonate and organic contents after demineralization. LDG showed no difference in phosphate content before and after pHC. Before pHC, MDG carbonate content was statistically greater than the one found in LDG. The presence of a correspondent calcium fluoride band was not observed in enamel spectrum. In conclusion, only carbonate quantity influenced enamel susceptibility to in vitro demineralization and FT-RAMAN is an appropriate technique to select homogeneous enamel samples.
