Scanning Electron Microscopic Observations of Epitaxial Growth-like Crystals in Human Early and Old Dental Calculi

抄録

By using scanning electron microscopy, the different crystals formed on basal crystals were observed in human dental calculus. In early calculus, polygonal column and triangular plate-shaped crystals of brushite or dicalcium phosphate dihydrate (DCPD) were formed on the mass of fine needle or sandygrain-shaped biological apatites (AP). In old calculus, elongated ribbon and plate-shaped crystals of octacalcium phosphate (OCP) were arranged on the glomerate structures of AP crystals; in addition, the alternation of these crystal layers were frequently observed. Hexahedrally based crystals of whitlockite (WH) were induced on the surfaces of OCP crystals and on the mass of AP crystals, while rod-shaped AP crystals were induced on the surfaces of WH crystals. Their appearances suggest that the epitaxial growth and transformation of DCPD, OCP, AP, and WH crystals easily occur in the microenvironment of dental calculus.