|0498 Enamel Fluoride Uptake from Fluoridated Carbamide Peroxide Bleaching Gel|
B.T. AMAECHI, L.M. CLARK, N. BARGHI, and J.B. SUMMITT, University of Texas - San Antonio / Health Science Ctr, USA|
Objective: Fluoride application on tooth surface is known to induce fluoride uptake into tooth tissue. We speculate that the current practice of adding fluoride into 10% carbamide peroxide bleaching (CP) gels, to limit whitening-induced tooth sensitivity experienced by some individuals, will result to enamel fluoride uptake. The aim of this study was to quantitatively determine enamel fluoride uptake after application of fluoridated CP gels, comparing it with non-fluoridated CP gels and Crest Sensitive® toothpaste. Method: 4 enamel blocks were cut from each of twenty extracted human molars. Each block was coated with acid-resistant nail varnish except for an exposed window (2 mm2). 4 blocks from each tooth were randomly assigned to four experimental groups: control (A), treated with non-fluoridated CP gel (B), treated with either CP gel (C) or Crest toothpaste (D) both containing 0.11% fluoride. The blocks were subjected to 8-hour treatment each day with their respective agent for 14 days to simulate manufacturer's bleaching instruction. Following treatment, the blocks were analyzed for potassium-hydroxide-soluble (KOHs) and structurally-bound (sb) fluoride. Through the exposed window, KOHs was extracted by 24-hours agitation in KOH solution, while sb was extracted by acid-etching and dissolution with HCLO4. Fluoride ion concentrations (F) in the resultant solutions were measured using ion selective electrode/meter. Data was analyzed statistically using paired t-test (n=20, α=0.05) to test for differences in the amount of both sb-F and KOHs-F among the four groups. Result: For sb-F, no significant differences in F between groups A and B, and between C and D. However, F was significantly lower in A(p<0.001) and in B(p<0.001) when compared with C and D. Similar trend was observed with KOHs-F. Conclusion: Application of fluoridated 10% carbamide peroxide gel resulted in enamel fluoride uptake comparable to toothpaste of similar fluoride concentration. "Funded in part by Ultradent Products Inc."
|Seq #71 - Fluorides/Other Caries Prevention|
2:00 PM-3:00 PM, Thursday, 9 March 2006 Dolphin Hotel Pacific Hall