EFFECT OF ENVIRONMENTAL pH ON GLASS IONOMER CONTAINING RESTORATIVES

Objective: To determine the effect of environmental pH on fluoride release and surface roughness (Ra) of glass ionomer containing restoratives. Methods:Four different glass ionomer containing restoratives Fuji IX Extra (FE), Fuji IX Fast (FF), Fuji II LC (FL), Beautifil II (BF) were evaluated.Specimens(n=6) were prepared and matured for 24 hours at 37ºC ± 100% humidity. The matured specimens were immersed in demineralizing solution of pH 4.5, 3.5 and 2.5.The immersion mediums were changed at weekly intervals and fluoride release was analyzed using Ion specific electrode. Statistical analysis was performed using one way Anova and Post hoc Scheffe's tests. Results: pH 2.5 resulted in highest fluoride release and Ra values. FE released the most fluoride in the first week (26.7±1.61ppm) whereas BF (4.85±0.5ppm) the least. Ra increased with time and was the highest for FE during the fourth week (0.77±0.06µm) where as BF showed least (0.23±0.02µm).Conclusions:Low environmental pH results in higher amount of fluoride release from glass ionomer restoratives at the expense of increased surface roughness. The amount of fluoride release is, however, material specific.