Effect of Metal Surface Treatment on the Masking Power of Opaque Porcelain

¹ Materials and Technology Branch, Dental Health Center, Public Health Service, San Francisco, California 94118, USA

Spectral reflectance was determined as a function of incremental thickness of opaque porcelain applied to precious metal alloy surfaces treated in three ways. Sandblasted and fine-ground surfaces required comparable thicknesses of porcelain to achieve the same degree of opacity at selected wavelengths, whereas specimens conditioned with a gold flashing agent required 40 to 60% less opaque porcelain to achieve the same result. A logarithmic model for predicting reflectance as a function of porcelain thickness was applicable for gold-flashed surfaces at wavelengths greater than 550 nm.