The Colorimetric Study of the Musking Porcelain The Evaluation of the Opacity Using a Hiding Power Index

• Published in: Nihon Hotetsu Shika Gakkai Zasshi Vol. 40; no. 3; pp. 459 - 463
• Main Authors: Satodate, Tamaki, Ishikawa(Nagai), Shigemi, Sawafuji, Futoshi, Endo, Tadaharu, Tatsumi, Hiroteru, Tada, Kenzo, Ishibashi, Kanji
• Format: Journal Article
• Language: Japanese; English
• Published: Japan Prosthodontic Society 01.06.1996
• Subjects: color; hiding power; musking porcelain; opacity; porcelain laminate veneer crown
• ISSN: 0389-5386; 1883-177X
• DOI: 10.2186/jjps.40.459

Translucency is a very important factor for obtaining an esthetic porcelain laminate veneer crown. This translucency is greatly affected by the opacity of the masking porcelain layer, but there is no objective criterion to evaluate the opacity. In general, opacity is well evaluated by hiding power. Therefore, hiding power of masking porcelain was calculated in this study using the ASTM (American Society for Testing and Materials) method. The reflectance value of each masking porcelain sample containing 5, 10, 15, 20, 25, or 30% opacity of pink, white, yellow, and blue were measured with white and black backing, and hiding power was calculated using its scattering coefficients. Hiding power increased in proportion to the opacity and ranged from 100 to 1, 400 for any shade. Color difference dE between white and black backing increased rapidly under the 25% opacity. It was concluded that (1) the opacity could be analyzed as hiding power and (2) hiding power under 20% opacity is very effective on visibility.