A comparison of fluoride release from various dental materials

Objective. The aim of this study was to determine, in vitro, the relative short-and long-term fluoride release from four resin-modified glass ionomers (Fuji II LC, Vitremer, Enforce & Advance), a polyacid-modified composite resin (Dyract compomer) and a bonding agent (OptiBond). Methods. All the materials were prepared as outlined by the manufacturers. Circular discs of the materials mentioned were suspended in water for up to 300 days and the non-cumulative 24-h fluoride release was determined potentiometrically at chosen times. Results. The amounts of fluoride released during the first day were Vitremer (1.46 mu g mm(-2)), Advance (1.18 mu g mm(-2)), Fuji (1.08 mu g mm(-2)), Optibond (0.33 mu g mm(-2)), Dyract (0.31 mu g mm(-2)) and Enforce (0.15 mu g mm(-2)). After the second day the sequence changed slightly and remained approximately the same for the rest of the 300-day period. There was also an increase in the fluoride release during the 60-200-day period relative to the previous period. Conclusion: In general the most fluoride was released by Advance and not by Fuji II LC or Vitremer. For most materials, fluoride is still released after 300 days. Furthermore, even a thin layer of bonding agent released a relatively high amount of fluoride (volume-wise the most) at the beginning. II is deduced that even the release of relatively ion: amounts of fluoride may result in significant concentrations of fluoride in a microleakage gap. (C) 1998 Elsevier Science Ltd. All rights reserved.