Double-layer porcelain veneers: Effect of layering on resulting veneer color

Statement of problem. Densely sintered aluminum oxide veneered with feldspa thic porcelain seems to be a promising technology for the fabrication of po rcelain laminate veneers, which provide both strength and esthetics. To eff ectively use this approach for porcelain veneers, practitioners should know how the resulting color is affected by adding a layer of veneering porcela in onto the aluminum oxide. Purpose. This study compared changes in CIE L*a*b* color coordinates of sim ulated stained teeth when covered with the aluminum oxide core disks alone and after the disks had been veneered with 3 different shades of porcelain. Material and methods. Fifteen aluminum oxide disks were divided into 3 grou ps. Each of 5 disks was veneered with porcelain of the Vita shades Al, A2, and B4, respectively. The colors of the substrate covered with the nonvenee red disks and the veneered disks were measured separately, and the color di fferences were calculated. Measurements of the disks on a white background were also performed and used as controls. The extracted data were compared with Vita shade values available from the literature. Results. Statistically significant differences in color coordinates of dark substrates were recorded between the substrate covered by an aluminum oxid e disk and the addition of veneering porcelain to the aluminum oxide disks. Veneering the aluminum oxide disks with A1, A2, and B4 porcelain produced significant differences in the resulting color when placed on a dark substr ate. The direction of the color modifications correlated with values obtain ed from the literature. The resulting color was also affected by the color of the underlying structures. Conclusion. Although aluminum oxide alone does have a degree of masking cap ability, the resulting color of porcelain veneers with the use of this mate rial carl successfully be modified with the veneering porcelain.