Ancient and Modern Specimens of Human Teeth: a Fourier Transform Raman Spectroscopic Study

Abstract

An assessment is made of the applicability of Fourier transform (FT) Raman spectroscopy to the analysis of ancient human teeth from archaeological sites. Comparisons are made between the Raman spectra of nine modern adult and two exfoliate (deciduous) teeth and those of eight specimens of adult teeth dating from the 4th–16th centuries AD. From the Raman spectra of modern teeth, complete vibrational assignments are proposed for the organic proteinaceous and inorganic carbonated hydroxyapatite components. Band intensity ratio measurements of ancient teeth indicate that the collagen component does not change its conformation with burial age. Several vibrational features arising from specific amino acid residues have been identified, especially proline and hydroxyproline, representing about 10% of the total collagen. Weak bands assigned to citrate have also been assigned. For the inorganic matrix components, quantitative estimations of carbonate content have been carried out. Measurements of the relative intensities of the δ(PO) vibrations at 590 and 430 cm-1 indicate different crystalline orientations in the dental enamel and dentine hydroxyapatite components. Preliminary studies of the phenomenon of ‘pink dentine’ found in ancient teeth from certain burial environments have also been made. It is concluded that FT-Raman spectroscopy can be applied successfully to the analysis of whole ancient teeth or tooth fragments. © 1997 by John Wiley & Sons, Ltd.