Abstract
This study was designed to revalue topical fluoride treatment time and the time to refrain from rinsing, drinking, or eating following a professional application.
In order to investigate the topical application time, human intact enamel was treated with APF solution (pH3.6, 9, 000ppmF-) for 0, 1, 2, 3, 4, and 6min. We measured the amount of fluoride penetrating into the enamel, and performed an acid resistance test on experimental groups and a control group. In all fluoride groups, the fluoride concentration in enamel subjects, after treatment with fluoride solution, was greater than in the control group. We found that the fluoride penetrated to the deep interior (200μm). In the 1min group, fluoride penetrating into enamel was 80-90%, and the other fluoride groups were more than the percentage of the 4min group. The acid resistance test showed significant difference between the 2min group and the 3min and the 4 min groups depending on the demineralization time. But we found that the other fluoride groups had the same acid resistance as the 4min group.
To investigate the time for refraining from rinsing, drinking, or eating following a professionally applied topical fluoride treatment, we immersed the enamel treated for 4min with APF into synthetic saliva for 8hr. We assumed that the immersion time was the time for abstaining from rinsing, drinking, or eating, and that stirring represented rinsing, drinking, or eating. Prolonged immersion resulted in greater amounts of fluoride remaining, but even at an immersion time of 0min, the enamel retained more than 2 times the fluoride in the control group in the deep layers.
These findings suggest that the application time can be shortened to 4min, and the time for refraining from rinsing, drinking, or eating following professional application can be shortened to 30min.
