Multivariate analysis of the effect of staining beverages on the optical properties of two provisional restorative materials

To evaluate the effect of staining beverages on the color stability, translucency and gloss of two provisional restorative materials. Sixty discs (8 mm x 2 mm) were manufactured for Duralay and Protemp 4. The discs were randomly divided according to the beverages: tea, coffee, wine, Coca-Cola and "Chicha morada" (n=12). The discs were polished and initial recordings of color and translucency were made with a spectrophotometer, and the gloss was measured with a glossmeter. The discs were immersed for 5 days in each of the beverages at 37◦C, and the color, translucency and gloss were recorded again. The differences between the initial and final records were calculated to obtain the values of ΔE, ΔTP, ΔGU. For the analysis, the two-way MANOVA model was chosen, and the significance level was set at 5%. A significant interaction was observed between the type of material and the staining beverages on the changes observed in the values of ΔE, ΔTP, ΔGU (