TOPICAL FLUORIDE AND GLASS-IONOMER MICROHARDNESS

Purpose: To evaluate the effect of topical fluoride gels on the microh ardness of three glass ionomer cements. Materials and Methods: Cylinde rs of Ketac-Silver, Photac-Fil, and Fuji II LC were fabricated, stored in distilled water at 37 degrees C for 48 hours, and exposed to a neu tral sodium fluoride gel (Karigel-N), an acidulated orthophosphoric ac id gel (Karigel), and a stannous fluoride gel (Omni) at 37 degrees C f or 36 hours. Knoop hardness was then recorded. Results: Statistical an alysis showed significant differences (P<0.01) between groups related to material and treatment. Ketac-Silver did not demonstrate significan t differences in hardness, whereas exposure to APF decreased the Knoop hardness of Fuji II LC and Photac-Fil.