[The chemical solubility and stability of low-melting dental porcelains]

The aim of this investigation was to study the chemical solubility of 3 new low-fusing ceramics (Duceram-LFC, Duceragold and Vita Omega 800) in comparison with a conventional PFM-ceramic (Vita Omega) together with different surface treatments. Additionally, the three-point flexure strengths were measured. Although the test conditions were very stringent in comparison to the standard solubility test, all ceramics comply with ISO/DIS 6872 specifications, and are thus deemed to be well tolerated in the oral environment. Vita Omega demonstrated the lowest chemical solubility. Mechanical polishing of the surfaces of LFC and Duceragold ceramics produced lower solubility results as compared to glazing. Vita Omega and Omega 800 behaved contrarily. After repeated hydrolysis testings Ducera-LFC demonstrated the highest disintegration resistance. The three-point flexure strengths of low-fusing ceramics were generally higher than that of the conventional PFM-ceramic. As opposed to the other ceramic materials tested, the flexure strength of Duceram-LFC increased significantly after hydrolysis testing.