Ceramics-Silikáty 57, (3) 196 - 200 (2013) |
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INTERACTION OF FLUORIDE COMPLEXES DERIVED FROM GLASS-IONOMER CEMENTS WITH HYDROXYAPATITE |
Lewis Selma M. 1, Coleman Nichola J. 1, Booth Samantha E. 1,
Nicholson John W. 2 |
1 Department of Pharmaceutical, Chemical and Environmental Sciences, School of Science,
University of Greenwich, Medway Campus, Chatham, Kent ME4 4TB, United Kingdom
2 School of Health, Sport and Applied Science, St Mary’s University College,
Waldegrave Road, Twickenham, Middlesex, TW1 4SX, United Kingdom
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Keywords: Fluoride, Hydroxyapatite, Dental cements, Glass-ionomers, Aluminium |
A study has been undertaken of the interaction of complexed fluoride extracted from glass-ionomer dental cements with
synthetic hydroxyapatite powder. Extracts were prepared from two commercial glass-ionomers (Fuji IX and ChemFlex)
under both neutral and acidic conditions. They were analysed by ICP-OES and by fluoride-ion selective electrode with
and without added TISAB to decomplex the fluoride. The pH of the acid extracts was 4, conditions under which fluoride
complexes with protons as HF or HF2-
, it also complexes with aluminium, which was found to be present in higher amounts
in the acid extracts. Fluoride was found to be almost completely complexed in acid extracts, but not in neutral extracts,
which contained free fluoride ions.
Exposure of these extracts to synthetic hydroxyapatite powder showed that fluoride was taken up rapidly (within 5 minutes),
whether or not it was complexed. SEM (EDAX) study of recovered hydroxyapatite showed only minute traces of aluminium
taken up under all conditions. This showed that aluminium interacts hardly at all with hydroxyapatite, and hence is probably
not involved in the remineralisation process. |
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