Shade variance in ceramic restoration and shade tab: An in vitro study

Background: In clinical practice aesthetics for any restoration needs to consider the parameters of surface form, translucency and colour. To achieve ideal aesthetics the colour replication process for dental porcelain is the most important step which comprises of a shade selection phase followed by shade duplication. Materials and Methods: The ceramic brands Vita VMK95 (classic) and Ivoclar classic V were used for comparison with Vita classic shade tab guide shades A2 and B2. The samples were made of specific shape, size, and were of the recommended dimensions from investing self-cure acrylic strips to casted NiCr specimens Objective. The objective of this study was to quantify the results in CIE AE units system for the colour differences between the Vita shade guide colours and two commercial porcelains for metal ceramic crowns. Results: The results indicated that the porcelains do not match the shade guides to which they are compared and shade variations exist between different lots of porcelain from the same and different manufacturer. Conclusion: Problems identified that porcelains do not match the shade guides to which they are compared and shade variations exist between different lots of porcelain from the same and different manufacturer