TRANSLUCENCY OF SHADED ZIRCONIA CORE MATERIAL

Statement of problem. With the development of various zirconia core shades, questions arise regarding the effect of the shaded zirconia on the translucency of ceramic crowns. Purpose. The purpose of this study was to investigate the translucency of the 3 Procera Zirconia shaded core materials. The hypothesis was that differences exist in the translucency of various shaded zirconia cores. Material and methods. Disk-shaped (0.6 +/- 0.01 x 12 mm) zirconia core (Procera Zirconia) specimens (n=90) were fabricated by the manufacturer using a CAD/CAM process. The disks were fabricated in 3 groups according to shade (light, medium, intense) (n=30). A spectrophotometer was used to measure contrast ratio (CR) which is indicative of translucency. One-way ANOVA was conducted to determine significant differences among the shades (alpha=.05). Results. A significant difference in translucency between the light and intense shades (P=.030) and the medium and intense shades (P<.001) was observed. There was no significant difference between the light and medium shades (P=.15). Conclusions. Shaded zirconia is partially translucent. In addition, significant differences in translucency measurements were identified between specific shades. (J Prosthet Dent 2011;105:304-307)