[In vitro uptake of fluoride from South African fluoride gel dentifrices]

An increasingly difficult situation in obtaining imported products has led to the development of a locally-manufactured topical fluoride gel. In order to evaluate the anticariogenic potential of the gel an in vitro study was conducted to compare the fluoride (F) uptake into the enamel from the locally-manufactured gel with that of two overseas products. Sound, unerupted third molar teeth were used in the study. One half of the buccal surface of each tooth was used as a control and the remaining half for conducting the experiment. Enamel biopsies (0.5 N HCLO4 3,143 mm2; 15 sec) were conducted prior to the F treatment (control halves) as well as 24 hours after F treatment (experimental halves). The fluoride concentrations ([F]) of the etching solutions were analyzed according to the potentiometric analytical method. The calcium concentrations were determined by means of a flame spectrophotometer. The [F] of the control halves of the teeth were used as a reference to determine the actual F uptake in the experimental halves after F treatment. The results obtained from the study showed that the teeth treated with the locally-manufactured F gel, revealed a significant uptake of fluoride in the enamel as well as an increased resistance to acid dissolution. Only one of the imported products showed a statistically significant higher fluoride uptake than the acidulated South African manufactured phosphate fluoride gel. There was a favourable overall comparison of the locally manufactured F gel with that of the overseas products.