1995 Fiscal Year Final Research Report Summary
High-resolution electron microscopic observation of initial enamel crystals.
| Project/Area Number |
06671831
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Morphological basic dentistry
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| Research Institution | TOKYO DENTAL COLLEGE |
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Principal Investigator |
TOHDA Hisako Tokyo Dental College, Assitant Professor, 歯学部, 講師 (80085828)
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| Co-Investigator(Kenkyū-buntansha) |
YANAGISAWA Takaaki Tokyo Dental College, Professor, 歯学部, 教授 (10096513)
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| Project Period (FY) |
1994 – 1995
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| Keywords | Enamel / Initial crystal / High-resolution electron microscopy / Hydroxyapatite / Octacalciumphosphate / Epitaxy |
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| Research Abstract |
Enamel crystals consist of hydroxyapatite (HA). In the initial process of enamel crystal formation, it has not yet been established whether organic substances or HA of denth crystal is involved in crystal nuclear formation. Furthermore, it is still nuclear whether the initial enamel crystal is HA by origin or it some other presursors.
We observed initial enamel crystals in porcine tooth germ by high resolution elestron microscopy and immunoelectron microscopy. the observed spacings of lattice fringes were 8.2A,10.4A,13.9A,16.5A.Among the calcium phosphates, only OCP has a larger lattice spacing than HA.
The lattice spacing of 8.2A represents the (100) plane of hydroxyapatite (HA). The other values were associates with OCP.
We obtained the lamellar mixed crystals of 10.4A and 8.2A.When the crystals grew, the number of lattice fringes increased and the lattice spacing was consistently 8.2A.
Enamel crystals, confirmed by the existence of amelogenin were in contact with dentin crystals. No crystals were found in stippled materials.
In the initial process of enamel crystal formation, OCP is a precursor of HA and grows epitaxially on dentin crystals.
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