ELIADES G*, PAPADOPOULOS T, TSETSEKOU A (Dental School, University of Athens, CERECO & EKEVYL, Greece)
The purpose of this study was to characterize the interface of a low fusing porcelain (Duceratin, Soding, Sweden) bonded to a casted Ti alloy (Titan, Morita, Japan). The elemental composition of the porcelain bonding agent and of the alloy as received and after casting were analyzed by XRF spectrometry. The porcelain-alloy interfaces were studied by SEM-EDS microanalysis. Secondary electron (SEI) and compositional backscattered electron images (COMPO) were recorded to evaluate the interfacial integrity and microstructure. Selected areas were analyzed by area and line scan images for the distribution of Ti, Sn, Si, K, Al and O. The results showed that the bonding agent was composed of Al, Si, Na, P, K, Ca, Ba, Ti, Fe, Zn, Rb, Sr, Zr and Sn while the alloy of Al, Si, Ti (1.37 % Al, 2.67 % Si, 95.65 % Ti as received and 5.21 % Al, 2.19 % Si and 92.61 % Ti as casted). SEM revealed random interfacial topography and significant bulk porosity in the bonding agent. The transitional zone of oxide ranged between 1-3 µm in thickness. The elemental distributions of Ti, Sn, Si and K stopped abruptly at the interface while O formed a gradient exceeding at maximum depth 3 µm inside the alloy. Al showed a very characteristic distribution with high concentration at the interface which implies contamination of the Ti surface from the sandblasting technique during processing of the casting. The Al interference may substantially affect the performance of the porcelain-alloy interface under functional loading.