Assessing the Impact of Treatment Duration and Demineralization on Enamel Fluoride Uptake.

Objectives: This study aimed to determine the effect of time span between exposing the enamel to calcium lactate and sodium fluoride and of a demineralized surface on the uptake of alkali-soluble fluorides. Materials and Methods: A total of 20 non-carious human wisdom teeth, were used. First 10 teeth, were cut into four slabs each and allocated to one of four groups: two treatment groups A) Calcium lactate followed by sodium fluoride with minimal delay (just drying between the two treatments); B) Calcium lactate followed by sodium fluoride with a delay of one hour; one of two control groups C) Sodium fluoride, as the positive control; D) Negative control group without treatment. The other 10 teeth were used for the second part of the research, each tooth was cut into 4 slabs and divided into one of two groups - the first group underwent two weeks of demineralization liquid treatment, the second group, as a control, underwent two weeks in deionized water. After two weeks, all slabs were treated with calcium lactate and followed with sodium fluoride 226ppm F-.Enamel fluoride uptake was determined by the fluoride extraction method by Caslavska and analyzed using a fluoride ion-specific electrode. Results: Enamel fluoride uptake showed no statistical difference regarding various durations of treatment between exposing enamel slabs to calcium lactate and sodium fluoride, as well as demineralization of the surface of the enamel. Conclusions: Time span between exposing enamel to calcium lactate and sodium fluoride and the demineralization process did not significantly affect the enamel uptake of alkali-soluble fluorides.