Abstract
Mechanical properties and structure of fired specimens of low-fusing porcelains for multi-purpose gold alloys (MPGA)recently developed were evaluated in comparison with those of conventional porcelain for metal-ceramic restorations. Three kinds of commercial low-fusing porcelains for MPGA with a firing temperature of 780〜845℃ were examined compared to a conventional commercial porcelain with a firing temperature of 960℃. Mechanical properties such as Vickers hardness, fracture toughness, and flexural strength and surface analyses such as X-ray diffraction analysis, SEM observation, and EPMA were evaluated on the fired specimens. Mechanical properties and fired structure of low-fusing porcelains for MPGA were influenced by a firing schedule fixed on the selected muffle. Mechanical properties of low-fusing porcelains for MPGA differed in the products which were influenced by the composition and structure of powder and fired block. Mechanical properties of some low-fusing porcelains for MPGA were similar or inferior to those of conventional porcelain.
