Abstract

FERNANDEZ, M. E et al. THEORETICAL STUDY OF OCTOCALCIUM PHOSPHATE-HYDROXYAPATITE (OCP-HA) INTERFACE MODEL. Rev. LatinAm. Met. Mat. [online]. 2002, vol.22, n.1, pp.52-56. ISSN 0255-6952.

Some experimental results indicate that HA and OCP can form an epitaxial interface with a minimum of interfacial energy, producing a smooth HA-OCP interface. The OCP-HA interface has become of great biological interest in the context of mineralized tissue formation. In this work we present the high-resolution transmission electron microscopy (HREM) simulated images obtained from a model of the OCP-HA interface generated after the ideas of Brown et al [1,2,3]. And from this model, based in the idea that the CDL corresponds to an epitaxially growth of HA on the OCP surface, a model for this planar defects also presented. Simulated images were obtained by the multislice method using the atomic positions for Ca, P, O and H as determined by Kay et al. [4] for HA and Brown [2] for OCP respectively. We calculate the model stability by quantum mechanics methods for Brown´s model after relaxation, the atoms had a split of 0.27 Å approximately. In our model the atoms after relaxation kept the same positions.

Keywords : Hydroxyapatite; Octacalcium phosphate; Central dark line; Tooth enamel; Image simulations; High resolution transmission electron images.