Comparison of glazed and polished dental porcelain.

Many ceramists advocate polishing, rather than glazing, to control the surface luster of metal ceramic restorations. There is concern that compared to a natural glaze, the polished surface might have inferior properties. This study compared apparent fracture toughness (Kc) and stainability of a commercially available metal ceramic system with either a glazed or polished surface finish. The indentation technique was used for Kc determinations and colorimetry measurements of specimens immersed in a coffee solution for staining. Higher fracture toughness values were found for the polished specimens. No differences were detected in the staining characteristics.