Color stability of glass-ionomers and polyacid-modified resin-based composites in various environmental solutions.

PURPOSE

To evaluate the degree of color stability of glass-ionomers (GIs) and polyacid modified resin-based composites (PMRBCs) in various environmental solutions.

MATERIALS AND METHODS

Seven polyacid-based esthetic restorative materials were used: three chemical-cured GIs, one resin-modified GI and three polyacid-modified RBCs. A light-cured resin-based composite (RBC) (Z 100) was used as a control. Disk type specimens were prepared and were aged in four different solutions (deionized water, 0.1 mole acetic acid solution, 75% ethanol, and 10% hydrogen peroxide solution) for 1, 7, 14, 21, 28, and 56 days. The specimens were kept at 37 degrees C throughout the study. Color coefficients (CIE Lab*) were measured by a reflection spectrophotometer with SCE mode, and the surface of specimens was examined by a stereo zoom microscope.

RESULTS

In deionized water, all specimens showed an acceptable color stability. All of the GIs and PMRBCs showed significant color change in 0.1 mole acetic acid solution. The light-cured resin-modified GI showed a significant color change in 75% ethanol solutions. 10% hydrogen peroxide solution resulted in degradation and a high degree of color change for chemical-cured GIs. The light-cured resin-modified GI and PMRBCs showed high color change in 10% hydrogen peroxide solution. The light-cured RBC (Control), showed excellent color stability in all experimental solutions.