Fluoride release from light-curing restorative materials

Purpose: To measure the in vitro fluoride release from three polyacid-modif ied resin-based composites (Dyract AP, Compoglass F, F2000) and one resin-m odified glass-ionomer cement (Vitremer VLC) for 28 days in two different bu ffer solutions. Material and Methods: 30 cylindrical specimens of each mate rial were prepared. Subsequently, 15 samples of each material were stored i n neutral (pH 6.8) and acidic (pH 4.0) buffer solution (5 mL), respectively . After 4, 8, 12 hrs and 1, 2, 4, 8, 14 days, respectively, the samples wer e transferred into new solutions. The fluoride content was determined with a fluoride sensitive electrode. Data were analyzed with ANOVA, followed by closed-test-procedure based on Kruskal-Wallis. Results: Compared to the neu tral solution, all materials showed a significantly higher release of fluor ide in acidic environment within the 28-day period (P < 0.001, ANOVA). In a cidic buffer solution Vitremer VLC and Compoglass F showed a significantly higher fluoride release than F2000 and Dyract AP (P < 0.001, closed-test-pr ocedure). In neutral solution Dyract AP showed the significantly lowest rel ease (P < 0.001, closed-test-procedure). Fluoride release from the material s tested is higher in an acidic environment than in a neutral environment.