Spectrophotometric evaluation of color match to VITA classical shade guide of four different veneering porcelain systems for metal ceramic restorations

PURPOSE: To determine by a spectrophotometric analysis the variations in color between the fabricated shade of four different porcelain systems and the intended shade when applied in a set thickness. METHODS: Four porcelain systems (Duceram Kiss, VITA Omega, Wieland Reflex, Ivoclar IPS d.SIGN) for metal ceramic restorations were selected. Three disk-shaped (15 mm diameter, 0.3 mm thickness) specimens per group were made for three different shades of the A color scale of the Vitapan classical shade guide. On a Cr-Co alloy, 0.15 mm of porcelain opaque and 1.0 mm of translucent porcelain was applied. The porcelain stratification was executed according to the manufacturers' indications. The color measures were made by the clinical spectrophotometer Easyshade. RESULTS: No statistically significant differences were found among the ceramic systems examined. The recorded differences in color between A2 porcelain disks and corresponding VITA shade tabs were closer (mean delta E = 2.50) than those recorded for shade A3 (mean delta E = 3.84) and shade A3.5 (mean delta E= 3.94) (P<0.05).