JDR JDR Most Cited Articles
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

This Article
Right arrow Full Text (PDF)
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Wong, L.
Right arrow Articles by Duncan, J. F.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Wong, L.
Right arrow Articles by Duncan, J. F.

Journal of Dental Research, Vol 66, 1735-1741, Copyright © 1987 by International & American Associations for Dental Research Online Journals

ARTICLES

The influence of incorporated and adsorbed fluoride on the dissolution of powdered and pelletized hydroxyapatite in fluoridated and non-fluoridated acid buffers

L. Wong, T. W. Cutress and J. F. Duncan
Dental Research Unit, Medical Research Council, Wellington, New Zealand.

The effects of fluoride (F) incorporated into hydroxyapatite (HA), adsorbed onto the HA surface, and fluoride in solution were studied during HA dissolution. Dissolution rates at pH 5.0 and 25 degrees C were determined in fluoridated (0.1, 5.0 micrograms/mL) and non-fluoridated buffers for the following powdered and pelletized synthesized HAs: non-fluoridated HA, partially-fluoridated (100, 1000, 37,000 micrograms/g) HA, and surface-adsorbed fluoridated (100, 1000 micrograms/g) HA. The dissolution rate curves were used to derive two components we have called 'diffusion' and 'surface chemical reactivity'. With powders, the rate-determining factor was surface chemical reactivity during the first 60 min. Diffusion was reduced by increasing the F levels in the apatite or buffer. In non-fluoridated buffers, diffusion was reduced 29% for apatite with 100 micrograms/g incorporated F and 99% with 37,000 micrograms/g. Diffusion was reduced by 37% and 81% by 0.1 and 5.0 micrograms/mL F, respectively, in the buffer. With pelletized HA, the rate-determining factor during the first 10 min was surface chemical reactivity. Diffusion then became relatively more important, but the diffusion rate was independent of F content. During the dissolution of powdered apatites, F was taken up by the remaining apatite solid, as evidenced by the lower F concentration in solution than that calculated to be released during dissolution. There was also a decrease in the F concentration of the 0.1 microgram/mL buffer as reaction progressed. Pelletized apatites did not release enough F to influence dissolution significantly. Surface-adsorbed F was more effective than incorporated F in reducing HA dissolution.(ABSTRACT TRUNCATED AT 250 WORDS)


This article has been cited by other articles:


Home page
 Crit. Rev. Oral Biol. Med.Home page
Y. Jin and H.-K. Yip
SUPRAGINGIVAL CALCULUS: FORMATION AND CONTROL
Crit. Rev. Oral. Biol. Med., September 1, 2002; 13(5): 426 - 441.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
IADR Journals Advances in Dental Research ®
Journal of Dental Research ® Critical Reviews (1990-2004)
Copyright © 1987 Institutional Access Guidelines