In vitro color stability of provisional restorative materials

Discoloration of provisional restorations can result in esthetic problems which are critically important in, for example, anterior areas and may compromise the acceptability of the restoration.

The purpose of this study was to investigate the effect of tea on provisional restorative materials.

This study was designed to measure the degree of color change of three acrylic resin provisional materials, before and after immersion in artificial saliva and artificial saliva-tea solution for 2 and 4 weeks.

Three types of acrylic provisional materials (duralay, tempron, acropars TRP), were studied. Twenty disks (20 ± 0.1 mm by 2 ± 0.05 mm) were fabricated from each material. Specimens were polished with acrylic bur using pumice and diamond polishing paste. Base line color was measured using a spectrophotometer. Ten disks were stored in artificial saliva and 10 were stored in a solution of artificial saliva and tea at room temperature. Color measurements were made after 2 and 4 weeks of immersion.

Differences in color changes were compared by two way ANOVA, across the six groups, followed by a Turkey-Kramer's multiple comparison test.

For specimens immersed in artificial saliva, the color change of methyl methacrylate materials; duralay (ΔE=4.94) and tempron (ΔE=6.54), was significantly more than butyl methacrylate material; acropars (ΔE=4.10). After immersion in an artificial saliva- tea solution, tempron exhibited less color change (ΔE=8.50) compared to duralay (ΔE=10.93) and acropars (ΔE=15.64).

Color stability of methyl methacrylate is higher than butyl methacrylates so if provisional materials are used for extended periods of time; tempron is preferred.