The Effect of Ceramic Thickness and Resin Cement Shade on the Color of Porcelain Laminate Veneers upon Discolored Substructure.
Abstract: Objectives: Using the porcelain veneers with stained or discolored teeth, such as those stained by tetracycline is reliable and can be a satisfactory choice for aesthetic restoration with Porcelain Laminate Veneers (PLV) with thicknesses between 0.50 mm and 1.00 mm. [1, 2, 7] The primary purpose of this study was to evaluate the effect of the different thicknesses of veneers, shades of t... read morehe resin cements, and thermocycling on the final color of the porcelain laminate veneers used on discolored substructures. Materials and Methods: A total of 48 disks were made with B1 shade of Lithium disilicate CAD/CAM blocks (IPS e.max, Ivoclar, Buffalo, NY) with 0.50 mm and 1.00 mm thicknesses. One light polymarizable resin cement system (Variolink II base, Ivoclar Vivadent) with a total of two shades was used for cementation (opaque and bleached). Each porcelain disk was cemented to composite resin blocks of C4 shade with 5.0 mm thickness (n=12). Color changes in the porcelain substructures after cementation were examined with a SpectroShade spectrophotometer, and then the samples were thermocycled for 5000 cycles. Color differences (ΔE) were calculated before and after thermocycling, and the results were tested using three way ANOVA tests (α = 0. 05). Results: A significant difference was found in the comparison of the two shades of cement on the final color of the veneer restoration at an alpha of 0.05. The opaque shade had a significantly lower mean ΔE than the bleach shade. Significant differences in final color of the restoration were also found in the comparison of two different ceramic thicknesses (0.50 mm and 1.00 mm). No significant differences were found in comparison of pre-thermocycling and post-thermocycling. Conclusions: 1. The final color of laminate veneer restorations is affected by the color of the resin cement. When used with different thicknesses, opaque resin cement has a better masking effect on the final color of the restoration compared to the bleach resin cement. 2. The thickness of the restoration has a direct effect on the final color of the restoration. A 1.0 mm ceramic thickness enhanced the final color of the restoration compared to the 0.5mm thickness. 3. Accelerating aging (thermocycling) had no significant effect on the color of the cemented laminate veneers. The results of this study will demonstrate that careful selection of resin cement color and/or the thicknesses of PLVs are critical factors in obtaining optimal esthetics in porcelain laminate restorations.
Thesis (M.S.)--Tufts University, 2015.
Submitted to the Dept. of Posthodontics.
Advisor: Ala Ali.
Committee: Najla Chebib, Marcelo Suzuki, and Jennifer Bassett Midle.
Keyword: Dentistry.read less