Rhim, So-Young2020-11-052020-11-0519991999(OCoLC)1140223517(OCoLC)on1140223517https://hdl.handle.net/2144/41633PLEASE NOTE: This work is protected by copyright. Downloading is restricted to the BU community: please log in with a valid BU account to access and click Download. If you are the author of this work and would like to make it publicly available, please contact open-help@bu.edu.Dissertation (DScD) --Boston University Henry M. Goldman School of Dental Medicine, 1999 (Prosthodontics).Includes bibliographic references: leaves 193-207.The purpose of this investigation was to study the resistance to acid degradation of four low-fusing ceramic materials (Duceram-LFC, Finesse, Vita Omega900, and Sensation), two heat-pressed ceramic materials　(Cerpress SL and　IPS Empress), and a conventional feldspathic ceramic (Vita Omega). The weight loss,　flexural strength,　modulus of elasticity, fracture toughness,　and microhardness before and after a standard hydrolysis test (ISO 6872)　was measured for all materials tested. Twenty bars (1.5x2.0x25mm)　of each low-fusing ceramic were fabricated from both dentin and enamel powders. Thirty bars of each heat-pressed ceramic were heat pressed from both layering and staining ingots according to manufacturer′s recommendations. Bars were randomly assigned to a control and treatment group. Treatment groups were weighed before and after placement in a Soxhlet extraction device containing a 4% acetic acid solution heated up to　80[degrees]C for 16 hours.　A four point bending was applied to all bars using an Instron with a crosshead speed of 0.5mm/min. [TRUNCATED]en-USThis work is protected by copyright. Downloading is restricted to the BU community. If you are the author of this work and would like to make it publicly available, please contact open-help@bu.edu.Dental porcelainThesis/Dissertation