PubMed ID: 8217887Two conventional topical fluoride preparations; APF and neutral 2% NaF gel and two fluoride varnishes; Duraphat and Fluor Protector, were applied to 60 permanent and 20 primary teeth. The teeth were halved to provide test and control groups, and the fluoride uptake was measured using a micro acid etch technique, after 30 seconds and 60 seconds etching periods. All topical fluoride preparations in our study caused some fluoride uptake in permanent and primary tooth enamel compared to the control groups. Duraphat and APF were found to be more effective than the other agents
