Ultrastructural study of fossil human tooth tissue.

The preservation of fossil human soft tooth tissue from extinct populations which inhabited the northeast of Argentina (fourteenth and fifteenth centuries) is described. Studies were performed using both Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). The preservation of the surface structure in Tomes fibrils and in odontoblastic processes was determined by SEM; whereas by TEM we could observe the dentin ducts occupied by acellular material, being the inner structure of the odontoblastic processes poorly preserved. It is suggested that such preservation is due to an "instantaneous phosphatization" occurring immediately after death as a result of the presence of calcium phosphate deposits.