陶材焼付鋳造冠のオペーク陶材に関する測色学的研究 第３報 オペーク陶材層による裏装金属色遮蔽効果に及ぼすデンティン陶材層の影響について

Abstract

We colorimetrically studied the objective color expression of porcelain fused to metal crowns. It has been previously reported that a single opaque porcelain layer should be 0.25mm thick in order to mask the color of the metal base, regardless of the opaque porcelain color.It was studied whether an opaque porcelain layer less than 0.25mm could mask the color of the metal base. The color of dentin porcelain baked on the 0.25mm thick opaque porcelain, which was baked on the metal base, was defined as each standard color. We studied the effects of the dentin porcelain layer on the metal color mask of the opaque porcelain layer according to the color difference. The following materials were used in fabricating samples:(1) 77.0% Ni-Cr alloy, (2) Yellow opaque porcelains B2O and B4O, (3) Red opaque porcelains D2O and D4O, (4) Yellow dentin porcelains B2B and B4B, (5) Red dentin porcelains D2B and D4B.The results were as follows:1. B2 color (light yellow): If the additional layer of dentin porcelain was over 0.4mm, the 0.25mm opaque porcelain layer could be reduced by 0.05mm.2. B4 color (dark yellow): If the additional layer of dentin porcelain was 1.4mm, the 0.25 mm opaque porcelain layer could not be reduced.3. D2 color (light red): If the additional layer of dentin porcelain was over 0.8mm, the 0.25 mm opaque porcelain layer could be reduced by 0.10mm.4. D4 color (dark red): If the additional layer of dentin porcelain was over 0.2mm, the 0.25 mm opaque porcelain layer could be reduced by 0.05mm.