The effect of magnesium oxide supplementation to aluminum oxide slip on the jointing of aluminum oxide bars

The purpose of this study was to investigate the effect of modifying aluminum oxide slips with magnesium oxide (MgO) tocreate a jointing material for In-CeramR Alumina. Jointed In-CeramR Alumina bars with In-CeramR Alumina slips containing0－1.0 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 toughnesswere assessed. The 0.3 mass％ MgO group showed the highest flexural strength among the jointed groups, and there were no statisticaldifferences between the joint-free control groups. The fracture surface of 0.3 mass％ MgO group showed increasedsintering densification with reduced micropore size. No linear shrinkage was observed with the addition of MgO to thealumina slip. Added MgO was also effective in boosting fracture toughness. The present findings indicate that the MgOsupplementedbinding material is useful for clinical applications