Journal of Functional Biomaterials (Mar 2023)

Fluoride Retention in Root Dentin following Surface Coating Material Application

  • Katsushi Okuyama,
  • Yasuhiro Matsuda,
  • Hiroko Yamamoto,
  • Kohtaku Suzuki,
  • Kohei Shintani,
  • Takashi Saito,
  • Mikako Hayashi,
  • Yukimichi Tamaki

DOI
https://doi.org/10.3390/jfb14030171
Journal volume & issue
Vol. 14, no. 3
p. 171

Abstract

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This study aimed to use an in-air micro-particle-induced X-ray/gamma emission (in-air µPIXE/PIGE) system to evaluate tooth-bound fluoride (T-F) in dentin following the application of fluoride-containing tooth-coating materials. Three fluoride-containing coating materials (PRG Barrier Coat, Clinpro XT varnish, and Fuji IX EXTRA) and a control were applied to the root dentin surface of human molars (n = 6, total 48 samples). Samples were stored in a remineralizing solution (pH 7.0) for 7 or 28 days and then sectioned into two adjacent slices. One slice of each sample was immersed in 1M potassium hydroxide (KOH) solution for 24 h and rinsed with water for 5 min for the T-F analysis. The other slice did not undergo KOH treatment and was used to analyze the total fluoride content (W-F). The fluoride and calcium distributions were measured in all the slices using an in-air µPIXE/PIGE. Additionally, the amount of fluoride released from each material was measured. Clinpro XT varnish demonstrated the highest fluoride release among all the materials and tended to show high W-F and T-F and lower T-F/W-F ratios. Our study demonstrates that a high fluoride-releasing material shows high fluoride distribution into the tooth structure and low conversion from fluoride uptake by tooth-bound fluoride.

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