A long term study of fluoride release from metal-containing conventional and resin-modified glass-ionomer cements

The objective of this study was to determine long term release of fluoride from a resin-modified glass-ionomer cement (RMGIC) (Fuji II LC (FLC)) compa red with that from two conventional acid-base setting cements (HiDense (HD) and KetacSilver (KS)) marketed for similar restorative purposes. Fluoride release from discs of cement immersed in water or artificial saliva was mea sured for 2.7years using an ion selective electrode technique. The RMGIC wa s affected by water if immersed immediately after setting. This is similar to conventional acid-base cements and the experimental method was designed to allow for this. Over the 2.7-year period, the RMGIC and HD released simi lar amounts of fluoride into both water and artificial saliva. In water, th e RMGIC released the most fluoride, while in artificial saliva the highest release was from HD. KS released the least amount of fluoride in both immer sing liquids. In artificial saliva, release was reduced to 17-25% of that f ound in water, with the RMGIC showing the greatest reduction. Both acid-bas e cured cements showed changes in colour over the 2.7-year span, while the colour of the RMGIC was stable. It was concluded that the RMGIC released eq uivalent or greater amounts of fluoride than the two acid-base cure glass-i onomers over a period of 2.7 years.