Effects of different drinks on stainability of resin composite provisional restorative materials.

STATEMENT OF PROBLEM: The ability of tooth-colored restorative materials for provisional restorations to resist stains is important when interim prostheses are worn for a long period. Discoloration of provisional restorative materials may result in patient dissatisfaction and additional time and expense for replacement. However, the effect of different staining agents on the color difference of resin composite restorative materials has not been completely clarified. PURPOSE: The purpose of this study was to evaluate the stainability of auto- and light-polymerized composite provisional restorative materials, reinforced microfill, and microhybrid resin composite restorative materials upon exposure to different staining agents. MATERIAL AND METHODS: Forty-five cylindrical specimens (15 x 2 mm) were prepared for each of an autopolymerized bis-acryl composite provisional restorative material (Protemp II), a light-polymerized composite provisional restorative material (Revotek LC), a reinforced microfill (Micronew), and a microhybrid composite (Filtek Z250, Herculite XRV) restorative material, using a brass mold. The specimens were wet-ground with 1000-grit silicon carbide abrasive paper for 10 seconds. The 5 restorative material specimens were divided into 9 groups (n = 5) and stored for 24 hours at 37 degrees C in different types of solutions: water, coffee, coffee with sugar, tea, tea with sugar, coffee with artificial creamer and sugar, cola, red wine, or sour cherry juice. Color of all specimens was measured before and after exposure with a colorimeter using CIE L * a * b * relative, and color changes (DeltaE * ) were then calculated. The data were analyzed with a 2-way analysis of variance (ANOVA), and mean values were compared by the Tukey HSD test (alpha = .05). RESULTS: The interaction of provisional restorative materials and staining agents was statistically significant ( P = .0001). For the 5 restorative materials tested, the lowest DeltaE * values were observed in the water, cola, and sour cherry juice groups. The highest color difference for all restorative materials was observed in the red wine groups. For microhybrid composite materials and light-polymerized composite provisional material, when tea and coffee groups with and without sugar were compared, both groups with sugar demonstrated a higher color difference than without sugar. When comparing the 5 different restorative materials, the reinforced microfill material group (Micronew) demonstrated significantly less color change than the other materials tested. The highest color difference in this study was observed for specimens in the light-polymerized composite provisional material group (Revotek LC). CONCLUSION: The reinforced microfill restorative material tested was found significantly more color stable than the autopolymerized bis-acryl, light-polymerized composite provisional restorative materials, and microhybrid composites tested. The largest color difference was observed in the light-polymerized composite provisional material. The presence of sugar in coffee and tea increased the color difference compared to coffee or tea without sugar for light-polymerized composite provisional material and microhybrid composites.

Effects of various finishing procedures on the staining of provisional restorative materials.

STATEMENT OF PROBLEM: The color stability of tooth-colored restorative materials for provisional restorations is of primary importance when provisional prostheses are worn long term. However, the effect of different polishing methods on the color difference of provisional restorative (PR) materials has not been completely clarified. PURPOSE: The purpose of this study was to investigate the effect of different polishing methods on color stability of 2- and 3-component autopolymerized bis-acrylic composites, a light polymerized composite, and a methyl methacrylate-based PR material upon exposure to a staining agent. Material and methods Sixty cylindrical specimens (15 x 2 mm) were prepared for each of bis-acryl composites (Protemp II and Luxatemp), a light-polymerized composite (Revotek LC), and a methyl methacrylate-based (TemDent) PR material by using a brass mold. The specimens were divided into 6 groups (n=10), and different polishing procedures were used, including pumice (P), diamond polishing paste (Dpp), polishing discs (Pd), and combinations of these. Unpolished specimens served as the control. The specimens were stored for 48 hours at 37 degrees C in a coffee solution. The color of all specimens was measured with a colorimeter (Minolta CR-300) before and after exposure, and color changes (DeltaE) were calculated. The data were analyzed with a 2-way analysis of variance, and mean values were compared by the Tukey Honestly Significant Difference test (alpha=.05). RESULTS: The provisional materials, surface polishing procedures, and interaction were significant (P <.05). In the light-polymerized composite group, the lowest color difference (DeltaE) was observed in Group P-Dpp (4.9) and Group P (5.3), which were not significantly different from each other. In the autopolymerized bis-acryl composites and the methyl methacrylate-based provisional materials, the lowest color difference (DeltaE) was observed in Group P-Dpp. The largest color difference for the light-polymerized and autopolymerized composites was observed in Group Pd-Dpp and Group Pd, which were not significantly different from each other. In the methyl methacrylate-based material group, the largest color difference was observed in Group Pd. When comparing the 4 different PR materials, the methyl methacrylate-based material group demonstrated statistically significantly less color change than the other provisional material tested. CONCLUSION: The methyl methacrylate-based PR material (TemDent) was found to be more color stable than the autopolymerized (Protemp II and Luxatemp) and light-polymerized (Revotek LC) composites tested. The use of diamond polishing paste after polishing with pumice significantly decreased the staining of methyl metacrylate and bis-acryl composites tested. The highest color-change values were obtained in the groups polished with polishing discs, which were found to be significantly different compared to values obtained with other polishing techniques.