Emerging Dental Applications of Raman Spectroscopy - Emerging Raman Applications and Techniques in Biomedical and Pharmaceutical Fields - page 263

Fig. 11.2. Representative Raman spectra in the fingerprint region of human tooth
enamel and dentin. Peak assignments are marked

Table 11.1. Raman spectral peak assignments of human tooth enamel and dentin

Peak (cm − 1 ) Assignment

959 ν 1 symmetric stretching mode of PO 4

431, 446 ν 2 symmetric bending mode of PO 4

1023, 1043, 1052, 1069 ν 3 asymmetric stretching mode of PO 4

579, 590, 608, 614 ν 4 asymmetric bending mode of PO 4

1104 ν 1 symmetric stretching mode of type A CO 3

1069 ν 1 symmetric stretching mode of type B CO 3

∼ 1242 Amide III (N-H)

∼ 1450 C-H bending mode

∼ 1665 Amide I (C=O)

asymmetric stretching mode and the ν 4 asymmetric bending vibrations (see

Table 11.1 for peak positions). Mixed in with the ν 1 symmetric

stretching mode of type B CO 3 2 − . The enamel spectrum does not show sig-
nificant peaks from other moieties aside from apatite. The spectrum of dentin
on the other hand, along with peaks from carbonated hydroxyapatite, con-
tains several additional bands that can be assigned to be characteristic of the
protein collagen. These spectra correlate well with the different biochemical
compositions of these tissue types, suggesting that Raman spectroscopy is well
suited for studying dental hard tissues.

ν 2 mode is the