[The mechanism of topical applied ion supplemented acidulated phosphate fluoride gel effects on dental enamel demineralization: an in vitro study].

The present study was carried out on dental enamel to describe surface changes in the scanning electron microscope and crystallites changes in the high-resolution transmitted electron microscope as related to treatments of topical applied ion supplemented acidulated phosphate fluoride (APFI) gel and artificial caries agent demineralization in vitro, which imitated in vivo with pH- cycling condition. Our data suggest that topical application of APFI gel produce some CaF2 spheres on the surface of enamel and some fluoride-containing apatites in dental enamel. The latter are considered as result of F- and CaHPO4 or hydroxyapatites. The essence of chemical reactions are discussed. The results confirm that enamel treated with APFI gel becomes more resistant to artificial caries agent and electron radiation damage.