The effect of cesium-containing leucite additions on the thermal and mechanical properties of two leucite-based porcelains

✍ Scribed by Rasmussen, Stephen T. ;McLaren, Charles I. ;O'Brien, William J.

• Publisher: John Wiley and Sons
• Year: 2004
• Tongue: English
• Weight: 269 KB
• Volume: 69B
• Category: Article
• ISSN: 0021-9304
• DOI: 10.1002/jbm.b.30008

✦ Synopsis

Abstract

It has been demonstrated that a Cs~2~O‐stabilized leucite porcelain was susceptible to a stress‐induced phase transformation, but toughening was not observed.1 It was hypothesized that if Cs~2~O‐stabilized leucite core particles were added to a cesium‐free matrix porcelain, selected or designed to enhance the toughening mechanism, toughening would occur. A commercial porcelain (VP) and a synthesized leucite‐based porcelain (NP) were the matrix materials. Core particles of Cs~2~O (0.0–2.0 mol%) containing synthetic leucite were mixed with the two cesium‐free matrix porcelains and vacuum fired into specimens for testing. The toughness of both types of matrix‐based materials was dependent upon cesium content of the added core particles with a maximum toughness reached for those containing 0.75 mol% Cs~2~O. The toughness of the 0.75 mol% specimens (1.42 MNm^−3/2^ for VP based and 2.15 MNm^−3/2^ for NP based) was statistically (p < .02) higher than either of the matrix materials alone or the matrix materials containing added core particles of synthetic cesium‐free leucite. However, the toughest materials (0.75 mol% Cs~2~O) were not the strongest materials, most likely because of large internal flaws. The results suggested that transformation toughening was possible. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 69B: 195–204, 2004