Abstract
To compensate for the sintering contraction of porcelain inlay processed with cold isostatic pressure, the effect of intermediate oxide addition was studied. After oxidation and firing at 970℃ for 55 sec for porcelain powder with the addition of 10 wt% of B, Si, Ti, SiO, TiO, or SnO, SnO was chosen due to its color tone and stable form. The effects of various concentrations and firing times or temperatures on dimensional change and bi-axial flexure of the inlay were investigated. The contraction decreased with increases in the SnO concentrations, showing expansion when 50 wt% or more of SnO was added. There were no significant changes when the firing time was prolonged to 5 hours or the firing temperature was raised to 1100℃. The strength decreased from 75 to 30 MPa as the SnO concentration increased from 10 to 80 wt%, although the porcelain made from original powder showed 120 MPa. The intermediate oxide addition seemed to effectively compensate for the firing contraction.
