In vitro evaluation of fluoride uptake from a thixotropic gel.

The in vitro fluoride uptake by dental enamel from two conventional acidulated phosphate fluoride gels was compared to a thixotropic acidulated phosphate fluoride gel. The fluoride concentration and enamel biopsy depths were determined using an acid-etch biopsy method based on calcium determinations. A significant fluoride uptake by dental enamel from a thixotropic topical fluoride agent following one minute of application was demonstrated. This trend was also true for the 4-minute topical applications. This study showed that the thixotropic gel was as good as but not superior to conventional acidulated phosphate fluoride gels in terms of promoting fluoride uptake.