Abstract
Salivary stone is thought to be a calcareous degenerative product occurred in the submandibular gland and parotid gland. The exact mechanism of the formation of calculi is not clear. By using a Raman spectroscopy, we studied the spectroscopic characterization of human salivary stone, and compared with that of the model materials such as enamel, dentine, bone tissues and synthetic hydroxyapatite (sHAP). Twelve human salivary stones removed by operations were used and its cross-section surfaces were investigated by a Raman spectroscopy. Enamel and dentin of impacted lower third molar tissues, the compact bone of rat femur and sHAP were measured as the model materials. Raman spectra were obtained by a JEOL JRS-FT6500N Raman spectrometer. A 1064 nm line from a continuous wave Nd:YAG laser was used for excitation. Raman spectral pattern for the human salivary stones was quite similar to that for enamel and sHAP, indicating that the principal constituent of the stone may be calcium phosphate and its structural characterization may be same as that for HAP. However, the spectral patterns for protein and CO32− were also observed in some cases, suggesting that some protein and CO32− may be one of the compositions of the stone. From these results, human salivary stones could be classified into three groups by the structural features; the HAP-structure group, the protein-rich HAP-structure group and the CO32−-rich HAP-structure group. [J Physiol Sci. 2007;57 Suppl:S120]
