Research Articles| November 17 2009 Influence of Fluoride Concentration on the Progress of Demineralization in Bovine Enamel at pH 4.5 (Short Communication) Subject Area: Dental Medicine , Further Areas J. Arends; J. Arends aMateria Technica, Dental School, Groningen, The Netherlands; Search for other works by this author on: This Site PubMed Google Scholar J. Christoffersen; J. Christoffersen bMedicinsk-Kemisk Institut, University of Copenhagen, Denmark Search for other works by this author on: This Site PubMed Google Scholar M.R. Christoffersen; M.R. Christoffersen bMedicinsk-Kemisk Institut, University of Copenhagen, Denmark Search for other works by this author on: This Site PubMed Google Scholar J. Schuthof J. Schuthof aMateria Technica, Dental School, Groningen, The Netherlands; Search for other works by this author on: This Site PubMed Google Scholar Caries Res (1983) 17 (5): 455–457. https://doi.org/10.1159/000260700 Article history Published Online: November 17 2009 Content Tools Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Facebook Twitter LinkedIn Email Tools Icon Tools Get Permissions Cite Icon Cite Search Site Citation J. Arends, J. Christoffersen, M.R. Christoffersen, J. Schuthof; Influence of Fluoride Concentration on the Progress of Demineralization in Bovine Enamel at pH 4.5 (Short Communication). Caries Res 1 May 1983; 17 (5): 455–457. https://doi.org/10.1159/000260700 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAll JournalsCaries Research Search Advanced Search Article PDF first page preview Close Modal Keywords: Demineralization, Enamel, Fluoride This content is only available via PDF. 1983Copyright / Drug Dosage / DisclaimerCopyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher.Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements. You do not currently have access to this content.
Remineralization experiments, carried out in double (45Ca and 32P) labelled solutions, indicated that a short-term acidulated phosphate fluoride pretreatment inhibits subsequent remineralization of initial enamel lesions. Mineral deposition is confined to an outer enamel region.
To investigate the mechanism of remineralization, artificial (HEC) lesions in bovine enamel and etched bovine enamel were remineralized in a pH-stat controlled system at 25, 37 and 50 °C. In all experiments 3 cm2 of demineralized enamel was immersed in 15 ml of a solution containing 1.5 mM Ca, 0.9 mM PO4 at pH = 7.0. The mineral deposition was followed by monitoring the alkali uptake and the changes of the calcium and phosphate concentration in solution. From the analytical data it was concluded firstly that in all cases hydroxyapatite precipitated. Secondly it was shown that the remineralization of both lesions and etched enamel was a second order chemical reaction. The rate of lesion remineralization is primarily determined by the diffusion in the surface layer pores, as indicated by the value of the activation energy (0.38 eV). For etched enamel the activation energy is 0.70 eV suggesting a surface reaction controlled process. Since the mechanism of remineralization of lesions and etched enamel is completely different it is dangerous to extrapolate results obtained with etched enamel to the situation of the clinically interesting remineralization of white spots.
In this paper a survey is given of some ultrastructural properties of synthetic hydroxyapatite. The preparation method by which single crystals with a length in the range of 0.1-3.0mm and a defined purity and stoichiometry can be produced is given. Two groups of materials are considered in detail: carbonate-rich (>0.1% CO3) and low-carbonate hydroxyapatites. The experiments on carbonate-rich material, being the most interesting from a biological point of view, show that acids attack at an active site in the hexagonal basal-plane of the crystals. Later on the crystals dis solve in the center of the crystal parallel to the c-axis forming tube-like structures. The active site can be protected from dissolution if the crystals are pretreated by EHDP or MFP. A comparison with lattice defect theory shows that most likely dislocations of the "hollow-core" type are responsible for the preferential dissolution.
A direct comparison of quantitative microradiography and microhardness profiles was made using artificial caries-like lesions in human enamel. Tooth crowns with lesions were cut in half through the center of the lesions and opposing halves were assessed by one of the techniques, from the anatomical surface, across the lesion, and into the underlying enamel. A linear relationship was found between volume percent mineral determined by microradiography and the square root of the Knoop Hardness Number assessed by microhardness testing in the mineral range of 40–90 volume percent. The relationship also holds for sound dentine. It is concluded that either technique can be used to measure mineral profiles through carious lesions as a result of demineralization and presumably remineralization.
