Reprecipitation Phenomena Arising During the Preparation of Demineralised Sections. III. Scanning Electron Microscopic Examination of Secondary Calcium Phosphate Deposits

Sections of teeth partly demineralised in 10% formic acid were examined by X-ray diffraction, microradiography and scanning electron microscopy. In the undemineralised 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.