Predicting porcelain thickness required for dental shade matches

Statement of problem. Production of a ceramic dental restoration that match es a target shade is dependent on porcelain thickness. Even when adequate p orcelain thickness exists, clinical shade matches are difficult to achieve. Purpose. This study predicted the thickness of dentin porcelain required to obtain a clinical shade match (less than or equal to 3 Delta E units) for a variety of dental porcelain systems and shades. Material and methods. Three all-ceramic crown systems (Empress, Inceram-Alu mina, Inceram-Spinell) and 2 metal ceramic systems (Vintage, VMK-95) were e valuated, each in shades A1, A3, and C2. Five specimens of each porcelain, of each shade, were fabricated at thicknesses of 1.0, 1.2, 1.5, and 2.0 mm. CIE-LAB coordinates were recorded for each specimen, and for the midgingiv al third of corresponding shade tabs with a Minolta CR-321 colorimeter. Results. Seventy percent of the color difference between specimen and shade tab was due to high L* (Munsell value) in the specimens. At thicknesses of less than or equal to 2.0 mm of dentin porcelain, the all-ceramic systems exhibited more shade matches than the metal ceramic systems. Conclusion. Specimens made from semi-translucent all-ceramic systems exhibi ted clinical shade matches that were superior to those made with the metal ceramic systems. Increasing thickness of the semi-translucent systems from 1.0 to 2.0 mm did not improve shade matching.