THE EFFECT OF VARIOUS SURFACE-COATINGS ON FLUORIDE RELEASE FROM GLASS-IONOMER CEMENT

To protect glass-ionomer cement from moisture contamination and dehydr ation during initial setting, immediate application of a surface coati ng agent is recommended. This study compared the effect of various sur face coatings on F release from glass-ionomer cement. Twenty glass-ion omer cement (Ketac-Fil Aplicap) disks (4.52 cm2) were prepared from a Teflon mold. The control group was uncoated, while the experimental gr oups were coated with Visiobond, Scotchbond II, and Ketac Varnish. In addition, five specimens of Variglass were similarly prepared and rema ined uncoated as per the manufacturer's instructions. F release was me asured each day during week 1 and on the last day of weeks 2, 3, and 4 . The results indicated that the application of the surface coatings d id not completely inhibit F release from glass-ionomer cements, and th at F release during the first week for all groups was significantly gr eater than in the subsequent 3 weeks. Visiobond-coated glass-ionomer c ement allowed significantly more F release than Scotchbond II-coated g lass-ionomer cement, Ketac Varnish-coated glass-ionomer cement, or Var iglass.