Interfacial Characterization of Porcelain Veneered on the Pure Titanium under Vacuum Firing

Abstract

The interfacial characteristics between porcelain coating and titanium under vacuum firing at 800 C have not been well documented. The cross-sectional variations in microstructures and compositions at the porcelain/Ti interface were investigated with a SEM and an EPMA equipped with WDS. The phase constituents of the porcelain bulk coating and the nearby porcelain/Ti interface were analyzed by X-ray and thin-film X-ray diffractometry respectively. In addition, a TEM equipped with EDS was used to examine the porcelain/Ti oxide interface. The experimental results revealed that the oxidation of Ti occurred at the porcelain/Ti interface, and it is reasonable to deduce that the Ti reduces the SnO 2 and SiO 2 components of the porcelain and becomes Ti oxide. Furthermore, redox reactions and chemical bonding occur at porcelain/Ti interface during firing and thus prevent the initiation of fracture from occurring at this interface. Subsequently, the fracture initiation tends to be located near the interface of newly formed Ti oxide and Ti substrate and/or slightly inside the Ti.

Effect of Crystallization on the Bonding Strength and Failures of Plasma-Sprayed Hydroxyapatite

“…The formation of titanium oxide often causes serious interfacial fractures at elevated heating temperatures, 29) and Fig. 3(a) reveals that the lowest bonding strength for atmospheric heating specimens at 700-800 C not only resulted from the above-mentioned HA crystallizationinduced cracks, but also the formation of detrimental interfacial TiO 2 .…”