DETERMINATION OF FLUORIDE RELEASE FROM LIGHT-CURED GLASS-IONOMERS ANDA FLUORIDATED COMPOSITE RESIN FROM THE VIEWPOINT OF CURING TIME

The purpose of this study was to investigate the fluoride releasing pa ttern of several visible light-curing glass-ionomers and one fluoride- containing filling material, from the viewpoint of curing time. Standa rdized blocks of Time Line (Caulk-USA), XR-Ionomer (Kerr-USA), Vitrebo nd (3M-USA) and Heliomolar-Ro (Vivadent-Lichtenstein) were light cured for 20, 40 and 60 s, and then stored in deionized distilled water at 37 degrees C for 24, 48, 72 h and 7 days. The water was changed every day and measurements of the fluoride released from the materials were made daily. The results were compared statistically with the results o btained from Ketac-Bond (Espe-Germany) prepared in the same manner. Th e levels were highest for the first 24 h; in the following days they d ecreased rapidly. The fluoride-releasing patterns of all these materia ls were similar to each other. The fluoride release was the highest fr om XR-Ionomer, and the lowest from Heliomolar-RO. For Time Line glass- ionomer, the fluoride release from 20 s cured blocks was significantly higher than the fluoride release from 40 and 60 s cured blocks at the end of 1 week. It was observed that the fluoride release from Ketac-B ond was significantly lower than XR-Ionomer and VitreBond and higher t han Time Line and Heliomolar-Ro.