A Comparison of the Fluoride 'Paint- On' vs Tray Application Techniques for Enamel Remineralisation.

BACKGROUND: Fluoride gel treatment is not recommended for children < 6 years old due to its potential toxicity. Hence the aim of this study was to compare the effect of 1.23% acidulated-phosphate fluoride (APF) gel paint-on and the conventional tray application techniques on artificial, deciduous enamel carious lesions embedded on wearable appliances. METHODS: In a randomised crossover study, the volunteer children (n = 29) wore mandibular removable appliances containing embedded tooth specimens with artificial carious lesions. The volunteers had 3 different treatment protocols: (I) 0.4 mL non-fluoride (control) gel, (II) 0.4 mL paint-on 1.23% APF gel or (III) 5 mL 1.23% APF gel, 4 minutes tray application. After 1 hour, the appliances were removed and the specimens underwent an in vitro, 14 days of pH-cycling. The mean percentage reduction in fluorescence (DeltaF, %) at baseline (DeltaF(0)) and after the pH-cycling (DeltaF(1)) were determined using quantitative light-induced fluorescence-digital analysis. The mean DeltaDeltaF (DeltaF(1)-DeltaF(0)) was calculated to compare the differences between groups. RESULTS: The mean DeltaDeltaF of groups I to III were -1.42 +/- 1.49, 1.06 +/- 2.11, and 1.12 +/- 3.57 and -1.25 +/- 1.44, 1.13 +/- 1.84 and 1.44 +/- 3.62 for the smooth surface and proximal surface lesions, respectively. The mean DeltaDeltaF in the 2 treatment groups were significantly greater compared with the control group (P < .001). There was no significant difference in DeltaDeltaF between the APF gel tray and paint-on groups either in the smooth surfaces, or the proximal surfaces (P = .629 and P = .613, respectively). CONCLUSION: Our study, for the first time, indicates that the paint-on application of APF gel or the tray application of APF had a similar enamel remineralisation effect. Clinically, this implies that, particularly in younger children, the paint-on application of fluoride is less cumbersome, and possibly more tolerable with a lesser likelihood of fluoride ingestion than the tray application technique. TRIAL REGISTRATION: Thai Clinical Trial Registry (https://www.thaiclinicaltrials.org/show/TCTR20190724001).