We have studied on the physicochemical characters of the porcelain materials in order to recognize the important factors concerning the bonding mechanism between porcelains and base-metal alloys at the metal/ceramic veneering technique.
The results were as follows.
By the X-ray Fluorescence analysis, main constituents of the every porcelain materials are SiO₂ and Al₂O₃. SnO₂, which is considered to effect on the bonding mechanism, was mainly contained in the opaque porcelains and its maximum content was 23.75%.
The composition of the so-called Metal Conditioner was similar to that of the dental porcelains.The particle sizes of the se porcelains were mainly classified in four kinds.
On the thermal expansion, the metastatic temperature was 500-600℃ and the coefficient of expansion was 0.73-1.36%.In the case of some base-metal elements were added to the porcelain materials, there was no remarkable change in the metastatic point and the thermal expansion.
But, the softening point shift to some higher temperature, the degree of the thermal expansion increase and also the fusible point somewhat rise.
The mechanical surface treatment of the alloys had more effect on the bonding strength than the chemical surface treatment.
As to the metal/ceramic boundary analysis by the electron probe X-ray microanalyser, the joint investigation of characteristic X-ray image and X-ray diffraction intensity map was a useful means to explain the diffusion state of elements at the both sides of the interface.