Spectrophotometric analysis of a nongreening, metal-fusing porcelain.

Spectrometric analysis has been used previously to examine color differences among various porcelains and metal ceramic systems. This study determined whether nongreening porcelain of a single shade fused to high-gold and palladium-silver alloys results in the same final color. Both conventional (VMK-68) and nongreening (VMK-68N) porcelains were fused to metal coupons of high gold (Will-Ceram Y) and palladium-silver (Will-Ceram W-1) to make up four groups. CIELAB colorimetric data were collected at each of seven fabrication steps to define color differences between steps for each alloy-porcelain group as well as between groups at each step. For the shade tested, perceptible color differences between high-gold/conventional porcelain and palladium-silver/nongreening porcelain coupons did not support manufacturers' claims.