Journal of Dental Research, Vol 71, 1558-1560, Copyright © 1992 by International & American Associations for Dental Research Online Journals
Fluoride retention in dentin after topical application of aminefluoride
E. Hellwig
Department of Operative Dentistry, University of Clinic of Dentistry, Germany.
The retention of KOH-soluble and structurally bound fluoride in dentin
after topical application of aminefluoride was investigated. One
cylindrical dentin sample was prepared from each of 40 extracted third
molars. All samples received one topical application of 1 microL of
aminefluoride solution (1.23% F) for three min. Ten of them were analyzed
immediately after fluoridation. The remaining 30 samples were mounted in
the buccal aspects of a special mouth application which was carried by a
person for five days. After one, three, and five days, 10 of the 30 samples
were removed from the appliance. In all samples, the amount of structurally
bound fluoride was determined in three layers (20 microns, 20 microns, 20
microns) by use of a special grinding technique. Before each grinding step,
the dentin specimens were analyzed for KOH-soluble fluoride. The total
amount of KOH-soluble fluoride in dentin was 48.7 +/- 14 micrograms/cm2. It
decreased drastically during the experimental period. Structurally-bound
fluoride increased one day after fluoridation in the first and second
layers. Thus, topical application of aminefluoride resulted in a
significant accumulation of KOH-soluble fluoride in dentin. This
precipitate was unstable, but fluoride ions released from it could perhaps
increase the amount of structurally bound fluoride.
