Effect of Sn-Addition on the Bonding Strength between Casting Au-Pt-Cu Alloy and SiO2-Based Porcelain
Effects of 0.5 wt% Sn-addition to the dental casting Au-12Pt-0.6Cu alloy on the interfacial microstructures and bonding strength between porcelain and the alloy were investigated. Porcelain powders (SiO2-based oxides) are bonded through a thermal schedule consisting of preoxidation, 1st firing, and 2nd firing. Interfacial microstructures were examined after pre-oxidation and 2nd firing, respectively, by scanning and transmission electron microscopy. The bonding strength of the Au-12Pt-0.6Cu and Au-12Pt-0.6Cu-0.5Sn alloys with porcelain was about 24.6 MPa and 46.2 MPa, respectively. The higher bonding strength of the Sn-added alloy compared with that of the alloy without Sn is attributed to the SnO2 formed at the interface between porcelain and the alloy during pre-oxidation. SnO2 layer is thought to enhance chemical bonding with various oxides in the porcelain and, accordingly, improve bonding strength.
Hyungsun Kim, Junichi Hojo and Soo Wohn Lee
S.H. Lee et al., "Effect of Sn-Addition on the Bonding Strength between Casting Au-Pt-Cu Alloy and SiO2-Based Porcelain", Materials Science Forum, Vols. 544-545, pp. 175-178, 2007