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Recent observations on enamel crystal formation during mammalian amelogenesis.
Anat Rec. 1996 Jun; 245(2):208-18.AR

Abstract

BACKGROUND

Enamel mineralization taking place during amelogenesis is a unique model to investigate carbonatoapatite formation in vivo. The abundance of proteinaceous crystal growth inhibitors, in particular amelogenins, contributes significantly to the mineralization process. Their putative roles are to prevent random proliferation of crystal nuclei and to regulate the growth kinetics and orientation of the formed enamel crystals.

METHODS

The enamel fluid surrounding the forming enamel crystals contains high concentrations of carbonate and magnesium ions, both of which seem to modulate the mineralization process. Particularly, Mg ions can adsorb onto enamel crystal surfaces in a manner to compete with Ca ions. Enamel mineral formed during amelogenesis is featured as calcium-deficient, acid phosphate-rich carbonatoapatites. Currently the most putative stoichiometry model for enamel mineral is (Ca)5-x(HPO4)v(CO3)w(PO4)3-x (OH)1-x.

RESULTS

Very significant changes in the morphology, stoichiometry, and solubility of enamel crystals occur during the various stages of amelogenesis. The early enamel mineralization comprises two events: the initial precipitation of the well-documented thin ribbons and the subsequent overgrowth of apatite crystals on those templates. The thin ribbons precipitated in the vicinity of the secretory ameloblasts have the highest contents of acid phosphate, particularly in the form of exchangeable species, whereas both the exchangeable and unexchangeable acid phosphate decrease concomitantly with the progress of the apatite overgrowth and the appearance of elongated hexagonal crystals in the late secretory stages.

CONCLUSIONS

Those morphological and compositional features seem to be consistent with the formation of precursors, such as octacalcium phosphate.

Authors+Show Affiliations

Department of Pathology, Nippon Dental University, Tokyo, Japan.

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, P.H.S.
Review

Language

eng

PubMed ID

8769664

Citation

Aoba, T. "Recent Observations On Enamel Crystal Formation During Mammalian Amelogenesis." The Anatomical Record, vol. 245, no. 2, 1996, pp. 208-18.
Aoba T. Recent observations on enamel crystal formation during mammalian amelogenesis. Anat Rec. 1996;245(2):208-18.
Aoba, T. (1996). Recent observations on enamel crystal formation during mammalian amelogenesis. The Anatomical Record, 245(2), 208-18.
Aoba T. Recent Observations On Enamel Crystal Formation During Mammalian Amelogenesis. Anat Rec. 1996;245(2):208-18. PubMed PMID: 8769664.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Recent observations on enamel crystal formation during mammalian amelogenesis. A1 - Aoba,T, PY - 1996/6/1/pubmed PY - 2000/6/20/medline PY - 1996/6/1/entrez SP - 208 EP - 18 JF - The Anatomical record JO - Anat. Rec. VL - 245 IS - 2 N2 - BACKGROUND: Enamel mineralization taking place during amelogenesis is a unique model to investigate carbonatoapatite formation in vivo. The abundance of proteinaceous crystal growth inhibitors, in particular amelogenins, contributes significantly to the mineralization process. Their putative roles are to prevent random proliferation of crystal nuclei and to regulate the growth kinetics and orientation of the formed enamel crystals. METHODS: The enamel fluid surrounding the forming enamel crystals contains high concentrations of carbonate and magnesium ions, both of which seem to modulate the mineralization process. Particularly, Mg ions can adsorb onto enamel crystal surfaces in a manner to compete with Ca ions. Enamel mineral formed during amelogenesis is featured as calcium-deficient, acid phosphate-rich carbonatoapatites. Currently the most putative stoichiometry model for enamel mineral is (Ca)5-x(HPO4)v(CO3)w(PO4)3-x (OH)1-x. RESULTS: Very significant changes in the morphology, stoichiometry, and solubility of enamel crystals occur during the various stages of amelogenesis. The early enamel mineralization comprises two events: the initial precipitation of the well-documented thin ribbons and the subsequent overgrowth of apatite crystals on those templates. The thin ribbons precipitated in the vicinity of the secretory ameloblasts have the highest contents of acid phosphate, particularly in the form of exchangeable species, whereas both the exchangeable and unexchangeable acid phosphate decrease concomitantly with the progress of the apatite overgrowth and the appearance of elongated hexagonal crystals in the late secretory stages. CONCLUSIONS: Those morphological and compositional features seem to be consistent with the formation of precursors, such as octacalcium phosphate. SN - 0003-276X UR - https://www.unboundmedicine.com/medline/citation/8769664/Recent_observations_on_enamel_crystal_formation_during_mammalian_amelogenesis_ L2 - https://doi.org/10.1002/(SICI)1097-0185(199606)245:2<208::AID-AR8>3.0.CO;2-S DB - PRIME DP - Unbound Medicine ER -