Determination by Charged Particles Activation of Fluoride Uptake in Human Dental Enamel

Abstract

Fluoride concentrations in the surface enamel of extracted incisors of adults were determined by prompt activation by proton bombardment. The teeth were then submitted to 4 min of topical fluoride treatments (commercial gels and solutions), and fluoride enrichments were measured after a short rinsing. The non-destructivity of the technique allowed to use the same area of the tooth before and after treatment. The highest amounts of fluoride were deposited in enamel treated with an amine fluoride solution (10,545 ppm). Good results were obtained with APF gels (2,200 ppm), whereas MFP gel gave a very low enrichment (243 ppm). Kinetic studies allowed to follow the rate of fluoride fixation which appears to vary according to a logarithmic scale.

Fluoride Deposition in Enamel from Monofluorophosphate Application

“…Kirkegaard [1977] for exam ple, performed 5 min topical treatments in vitro with 0.56 M MFP pH 7 followed by incubation in a humid atmosphere for 24 h and found minimal fluoride deposition which was limited to the outer 3 ,«m. In our laboratories, we were unable to demonstrate in vitro fluoride deposition in enamel from 1, 0.79 or 0.5 M MFP at pH 5.5 applied for 5 min followed by 24 h washing in calcium phosphate solution with a pH of 5.5 [Gr0n et al, 1971], Similarly, Baijot-Stroobanls andVreven [1979] found very limited fluo ride enrichment of enamel from application of a commercial MFP gel.…”

In-vivo analysis of the permanent incorporation of fluorine in tooth enamel

“…This goal was achieved by proton induced gamma ray emission (PIGE) probably for the first time in 1974 [7]. New developments were initiated and amplified at LARN over the last 40 years on a large variety of extracted teeth (deciduous and permanent) [8][9] and later for the investigation in-vivo [10][11][12][13][14][15][16][17]. The proton beam is produced by a low energy accelerator: a single ended Van de Graff accelerator and later (1998) a Tandem linear accelerator (Figure 1).…”

Fluoride and Monofluorophosphate Analysis

“…Most use the fluo ride electrode on dissolved samples. The use of proton bombardment has also been re ported [Rytomaa et al, 1974;Rujan et al, 1976: Baijot-Stroohants andVreven. 1979].…”