The Effect of Magnesium Oxide Supplementation to Aluminum Oxide Slip on the Jointing of Aluminum Oxide Bars

Abstract

The purpose of this study was to investigate the effect of modifying aluminum oxide slips with magnesium oxide (MgO) to create a jointing material for In-Ceram ® Alumina. Jointed In-Ceram ® Alumina bars with In-Ceram ® Alumina slips containing 0-1.0 mass％ MgO were examined by a three-point bending test. Joint-free bars were also tested as controls. Fracture surfaces were evaluated by scanning electron microscopy. In addition, linear shrinkage and fracture toughness were assessed. The 0.3 mass％ MgO group showed the highest flexural strength among the jointed groups, and there were no statistical differences between the joint-free control groups. The fracture surface of 0.3 mass％ MgO group showed increased sintering densification with reduced micropore size. No linear shrinkage was observed with the addition of MgO to the alumina slip. Added MgO was also effective in boosting fracture toughness. The present findings indicate that the MgOsupplemented binding material is useful for clinical applications.

Effect of MgO and PVA on the Synthesis and Properties of Negative Thermal Expansion Ceramics of Zr2(WO4)(PO4)2

“…The enhancement mechanism of relative density of samples can be ascribed to the role of moderate amount of MgO to reduce the size, restrain reuniting or facilitate dispersion of particles. 24,25 However, it is also possible for Mg 2+ to substitute Zr 4+ in the lattice due to the same ionic radius (72 pm) of Mg 2+ and Zr 4+ . The substitution could yield anion vacancies that enhance diffusion.…”

Flexural strength of the joint between glass-infiltrated alumina frames and the alumina-magnesia modifier

“…The concentration of magnesia 0.3% derived from the previous study. 6 It is reported that the addition of magnesia to alumina ceramics controls the distribution of alumina with a uniform particle size, crack bowing, crack deflection, and the wetting properties of the particle surface. Optimizer.…”

“…The joined specimens were stored at room temperature for one hour after preparation and then sintered in a porcelain furnace (Austromat 3001, Dekema Dental-Keramiköfen GmbH, 6 Freilassing, Germany) ( Table 2). In-Ceram Alumina Glass Powder (Vita Zahnfabrik) was first applied to the sintered specimens; the specimens were then placed on a platinum metal foil (Ishifuku Metal Industry Co. Ltd., Tokyo, Japan); finally, glass infiltration firing and glass control firing were carried out according to the firing schedule recommended by the manufacturer (Fig 2).…”

“…4,5 The authors have 5 previously reported that the addition of a trace amount of magnesia to In-Ceram Alumina slips (Vita Zahnfabrik) significantly improved the bonding to In-Ceram Alumina. 6 The purpose of the present study was to investigate the flexural strength of In-Ceram Alumina joined with an experimental adjusting agent containing alumina and magnesia.…”