EVALUASI KEKERASAN RESTORASI NIKEL-KROMIUM DENGAN BERBAGAI METODE CASTING

Abstract

Non precious alloys were used widely in destistry, because cost was relatively lower than noble alloys (precious alloy). This study aims to evaluate the microhardness NiCr alloys were frequently used in the construction of crown and bridges prosthodontics and metal frame dentures with different methods. Casting methods used were: 1) induction/argon, the argon electromagnetic induction with controlled atmospheric pressure, 2) induction/vacuum, the electromagnetic induction in a vacuum environment, 3)induction/air, electromagnetic induction air was not controlled by atmospheric pressure and 4)flame/air from combustion of gas/oxygen in centrifugal castings machine was not cotrolled by atmospheric pressure. The three of alloys used were Ni-Cr-Mo-Ti: Ni-Cr_mo_Be and Ni-Cr-Mo-Nb. The sample size was 60, divided into 12 group (each group consisted of 5 samples) Cylindrical samples with a length of 15 mm and a diameter of 1.6 mm