Reprecipitation phenomena arising during the preparation of demineralised sections. III Scanning electron microscopic examinations of secondary calcium phosphate deposits.

Sections of teeth partly demineralized in 10% formic acid were examined by X-ray diffraction, microradiography and scanning electron microscopy. In the undemineralized circumpulpal dentin, the tubules were empty, lying in a matrix containing hydroxyapatite. In the "plume" areas of remineralisation, the tubules were filled with mineral deposits. X-ray diffraction revealed the presence of brushite and monetite in these areas. In the outer layers of dentin the tubules were empty, lying in a matrix containing some residual hydroxyapatite. These findings confirmed that the remineralisation process occurred within the dentinal tubules.