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Ultra‐small‐angle X‐ray scattering–X‐ray photon correlation spectroscopy studies of incipient structural changes in amorphous calcium phosphate‐based dental composites
Author(s) -
Zhang Fan,
Allen Andrew J.,
Levine Lyle E.,
Espinal Laura,
Antonucci Joseph M.,
Skrtic Drago,
O'Donnell Justin N. R.,
Ilavsky Jan
Publication year - 2012
Publication title -
journal of biomedical materials research part a
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.849
H-Index - 150
eISSN - 1552-4965
pISSN - 1549-3296
DOI - 10.1002/jbm.a.34018
Subject(s) - materials science , amorphous calcium phosphate , amorphous solid , small angle x ray scattering , x ray , composite material , scattering , spectroscopy , calcium , dynamic light scattering , optics , crystallography , nanotechnology , metallurgy , physics , quantum mechanics , chemistry , nanoparticle
Abstract The local structural changes in amorphous calcium phosphate (ACP)‐based dental composites were studied under isothermal conditions using both static, bulk measurement techniques and a recently developed methodology based on combined ultra‐small angle X‐ray scattering–X‐ray photon correlation spectroscopy (USAXS–XPCS), which permits a dynamic approach. While results from conventional bulk measurements do not show clear signs of structural change, USAXS–XPCS results reveal unambiguous evidence for local structural variations on a similar time scale to that of water loss in the ACP fillers. A thermal‐expansion‐based simulation indicates that thermal behavior alone does not account for the observed dynamics. Together, these results suggest that changes in the water content of ACP affect the composite morphology due to changes in ACP structure that occur without an amorphous‐to‐crystalline conversion. It is also noted that biomedical materials research could benefit greatly from USAXS–XPCS, a dynamic approach. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 2012.