The world's first wiki where authorship really matters (Nature Genetics, 2008). Due credit and reputation for authors. Imagine a global collaborative knowledge base for original thoughts. Search thousands of articles and collaborate with scientists around the globe.

wikigene or wiki gene protein drug chemical gene disease author authorship tracking collaborative publishing evolutionary knowledge reputation system wiki2.0 global collaboration genes proteins drugs chemicals diseases compound
Hoffmann, R. A wiki for the life sciences where authorship matters. Nature Genetics (2008)

Leucite content of selected dental porcelains.

Leucite is a major crystalline component of dental porcelains. The presence of tetragonal leucite in dental porcelains increases their coefficients of thermal expansion due to its high coefficient of thermal expansion (20-25 x 10(-6)/degrees C). This is particularly useful for those porcelains designed for bonding to precious metals and nickel alloys. The purpose of this study was to determine the leucite content of selected commercial dental porcelains in relation to their coefficient of thermal expansion values. The weight fraction of leucite was determined with quantitative x-ray diffraction using copper as an internal standard. Coefficient of thermal expansion values were determined using a thermal dilatometric analyzer. Five commercial body porcelains were studied. Leucite was not detected in samples of Vitadur N and Duceram LFC. An ANOVA showed that there was a significant difference in the weight fraction of leucite for Silhouette, Ceramco II, and Optec HSP porcelains. Linear regression revealed a correlation (R = 0.91) between weight fraction of leucite and the coefficient of thermal expansion for those samples containing leucite. Duceram LFC, which is recommended by the manufacturer for use with metals and leucite-containing porcelains, had no detectable leucite although the coefficient of thermal expansion was found to be 13.2 +/- 0.4 x 10(-6)/degrees C at 25-472 degrees C. A low glass transition temperature contributed to the high average coefficient of thermal expansion value.[1]


  1. Leucite content of selected dental porcelains. Piché, P.W., O'Brien, W.J., Groh, C.L., Boenke, K.M. J. Biomed. Mater. Res. (1994) [Pubmed]
WikiGenes - Universities