산화처리된 Metal Cap과 도재간의 전기화학적 특성

Abstract

Co-Cr and Ni-Cr alloys have been used for dental prosthetic alloys of partial denture framework, PFM metal cap and crown bridge because of superior to mechanical properties and low specific gravity. Corrosion resistance and bonding strength between ceramic and metal depend on their compatibility between prosthesis and gingiva tissue. This study is research of electrochemical characteristics between Ni-Cr alloys after artificial oxide film formed on the metal cap surface and ceramic. In order to investigate electrochemical characteristics of the oxide film formed metal cap-ceramic interface, casting alloys (PDS : 74Ni-12Cr-5Mo) were prepared and fabricated with centrifugal casting(Kerr, USA) at 1200℃. The surface of casting alloy is sandblasted, treated with vera disk. Specimens are divided into four group : non-degassing, degassing, degassing+artificial oxide film, non-degassing+artificial oxide film. The casting morphologies were analyzed using FE-SEM, EDX, and XRD. The electrochemical characteristics of the oxide film formed metal cap-ceramic interface was carried out using potentiodynamic test(M263A, EG＆G, USA) in artificial saliva solution at 36.5±1℃ from -700 mV to 1400 mV. The results are as follows : 1. The surface of non-degassed metal coping is not detected oxide film. But, the surface of degassed metal coping is detected oxide film of NiO, the surface of artificial oxidation after degassed metal coping is detected oxide film of NiCrO_(4) using XRD. 2. Pitting corrosion in case of PFM treated and the degassing specimen is higher than that of the non-degassing sample, E_(pit) values of artificial oxidation after degassed metal coping specimen is 225 mV after potentiodynamic test. 3. NiO, NiCr_(2)O and Cr_(2)O_(3) peaks is detected on the surface of degassed sample using XRD after potentiodynamic test. 4. The corrosion resistance of PFM decreased in the order of artificial oxidation after degassed, artificial oxidation after non-degassed, degassed and non-degassed specimens.