In Situ Atomic Force Microscopy Observation of Octacalcium Phosphate (100) Face Dissolution in Weak Acidic Solutions


Dissolution of the (100) face of octacalcium phosphate (OCP) single crystal in weak acidic solutions (pH = 6.5; 25°;C) was observed in situ using atomic force microscopy. Monomolecular steps (2.0 nm high) were observed; they originated from etch pits or crystal edges. Advancement of the dissolution process led to precipitation of nanoparticles as small as ~10 nm even though the solution was undersaturated with respect to OCP. This precipitation of nanoparticles was accompanied by a drastic decrease in the dissolution rate; however, the substrate OCP continued to dissolve, indicating that dissolution and growth occurred simultaneously on the same surface. The precipitated nanoparticles coalesced and eventually covered the entire surface without changing the surface morphology of the substrate crystal. The step height after complete coverage was ~2.0 nm, the same as that observed on the dissolving OCP surface. These findings indicate that the precipitated phase was a pseudomorph of OCP crystal.

Share and Cite:

Onuma, K. and Iijima, M. (2015) In Situ Atomic Force Microscopy Observation of Octacalcium Phosphate (100) Face Dissolution in Weak Acidic Solutions. Journal of Crystallization Process and Technology, 5, 1-8. doi: 10.4236/jcpt.2015.51001.

Conflicts of Interest

The authors declare no conflicts of interest.


[1] Aoba, T. and Moreno, E.C. (1990) Changes in the Nature and Composition of Enamel Mineral during Porcine Amelogenesis. Calcified Tissue International, 47, 356-364.
[2] Aoba, T. and Moreno, E.C. (1992) Changes in the Solubility of Enamel Mineral at Various Stages of Porcine Amelogenesis. Calcified Tissue International, 50, 266-272.
[3] Watson, M.L. (1960) The Extracellular Nature of Enamel in the Rat. Journal of Biophysical and Biochemical Cytology, 23, 447-497.
[4] Rönnholm, E. (1962) The Amelogenesis of Human Teeth as Revealed by Elcectron Microscopy. (II) The Development of the Enamel Crystallites. Journal of Ultrastructure Research, 6, 249-303.
[5] Nylsen, M.U., Eanes, E.D. and Omnell, K.A. (1963) Crystal Growth in Rat Ename. Journal of Cell Biology, 18, 109- 123.
[6] Travis, D.F. and Glimcher, M.J. (1964) The Structure and Organization of, and the Relationship between the Organic Matrix and the Inorganic Crystals of Embryoic Bovine Enamel. Journal of Cell Biology, 23, 447-497.
[7] Diekwisch, T.G.H., Berman, B.J., Gentner, S. and Slavkin, H.C. (1995) Initial Enamelcrystals Are Not Spatially Associated with Mineralized Dentin. Cell and Tissue Research, 279, 149-167.
[8] Kerebel, B., Daculsi, G. and Kerebel, L.M. (1979) Ultrastructural Studies of Enamel Crystallites. Journal of Dental Research, 58, 844-850.
[9] Weiss, M.P., Vogel, J.C. and Frank, R.M. (1981) Enamel Crystallites Growth: Width and Thickness Study Related to the Possible Presence of Octacalcium Phosphate during Amelogenesis. Journal of Ultrastructure Research, 76, 286-292.
[10] Robinson, C., Briggs, H.D., Atkinson, P.J. and Weatherell, J.A. (1984) Matrix and Mineral Changes in Developing Enamel. Journal of Dental Research, 58, 871-880.
[11] Weidmann, S.M., Weatherell, J.A. and Hamm, S. (1967) Variations of Enamel Density in Sections of Human Teeth. Archives of Oral Biology, 12, 85-97.
[12] Fearnhead, R.W. (1960) Mineralization of Rat Enamel. Nature, 188, 509-600.
[13] Brown, W.E. (1966) Crystal Growth of Bone Mineral. Clinical Orthopaedics, 44, 205-220.
[14] Nelson, D.G.A. and Barry, J.C. (1989) High Resolution Electron Microscopy of Nonstichrometric Apatite Crystals. The Anatomical Record, 224, 265-276.
[15] Iijima, M., Tohda, H., Suzuki, H., Yanagisawa, T. and Moriwaki, Y. (1992) Effect of F- on Apatite Octacalcium Phosphate Intergrowth and Morphology in a Model System of Tooth Enamel Formation. Calcified Tissue International, 50, 357-361.
[16] Miake, Y., Shimoda, S., Fukae, M. and Aoba, M. (1993) Epitaxial Overgrowth of Apatite Crystals on the Thin-Ribbon Precursor at Early Stages of Porcine Enamel Mineralization. Calcified Tissue International, 53, 249-256.
[17] Iijima, M. and Moradian-Oldak, J. (2004) Control of Octacalcium Phosphate and Apatite Growth by Amelogenin Matrices. Journal of Materials Chemistry, 14, 2189-2199.
[18] Beniash, E., Simmer, J.P. and Margoris, H.C. (2005) The Effect of Recombinant Mouse Amelogeneses in the Formation and Organization of Hydroxyapatite Crystals in Vitro. Journal of Structural Biology, 149, 182-190.
[19] Tao, J., Pan, H., Zeng, Y., Xu, X. and Tang, R. (2007) Roles of Amorphous Calcium Phosphate and Biological Additives in the Assembly of Hydroxyapatite Nanoparticles. Journal of Physical Chemistry B, 111, 13410-13418.
[20] Wang, L., Guan, X., Chang, D., Moradian-Oldak, J. and Nancollas, G.H. (2007) Amelogenin Promotes the Formation of Elongated Apatite Microstructures in a Controlled Crystallization System. Journal of Physical Chemistry C, 111, 6398-6404.
[21] Yang, X.L., Wang, L., Qin, Y., Sun, Z., Henneman, Z.J., Moradian-Ordak, J. and Nancollas, G.H. (2010) How Amelogenin Orchestrates the Organization of Hierarchical Elongated Microstructures of Apatite. Journal of Physical Chemistry B, 114, 22293-22300.
[22] Onuma, K. and Ito, A. (1998) Cluster Growth Model for Hydroxyapatite. Chemistry of Materials, 10, 3346-3351.
[23] Onuma, K., Kanzaki, N., Ito, A. and Tateishi, T. (1998) Growth Kinetics of Hydroxyapatite (0001) Face Revealed by Phase Shift Interferometry and Atomic Force Microscopy. Journal of Physical Chemistry B, 102, 7833-7838.
[24] Treboux, G., Layrolle, P., Kanzaki, N., Onuma, K. and Ito, A. (2000) Symmetry of Posner’s Cluster. Journal of the American Chemical Society, 122, 8323-8324.
[25] Kanzaki, N., Treboux, G., Onuma, K., Tsutsumi, S. and Ito, A. (2001) Calcium Phosphate Clusters. Biomaterials, 22, 2921-2929.
[26] Elliot, J.C. (1994) Structure and Chemistry of the Apatites and Other Calcium Orthophosphates. Elsevier, Amsterdam.
[27] Sugiura, Y., Onuma, K., Nagao, M. and Yamazaki, A. (2014) Alteration of Formation Dynamics and Material Structure in Phase Transformation from Amorphous Calcium Phosphate to Octacalcium Phosphate Using Immobilized Carboxylic-Functional Group on Gold Nanoparticles. American Mineralogist, Submitted.

Copyright © 2022 by authors and Scientific Research Publishing Inc.

Creative Commons License

This work and the related PDF file are licensed under a Creative Commons Attribution 4.0 International License.