In vivo uptake of fluoride by surface enamel of cleaned and plaque-covered teeth

Utilizing a newly developed biopsy method, the F uptake in the outer 3 mum of enamel from a single topical application of neutral NaF or amine F solution was tested on cleaned and plaque-covered premolars in 12- to 14-year-old children. Cleaned teeth treated with neutral NaF acquired only insignificant amounts of F. The presence of plaque seemed to enhance the deposition of F in surface enamel. The findings were discussed in relation to the possible mechanisms of action of topically applied fluorides. Topical treatments with amine F increased surface enamel F considerably more than the NaF. The F uptake was similar in cleaned and plaque-covered teeth. It was suggested that the usually performed plaque-removing procedures prior to topical F applications are superfluous and may even be disadvantageous.