치과용 어버트먼트 나사의 임피던스 특성

Abstract

Dental implant system is composed of abutment, abutment screw and implant fixture connected with screw. The problems of loosening and fracture of abutment screw depend on surface characteristics. The purpose of this study was to evaluate the corrosion behavior of abutment screws with A.C impedance. The abutment screws of 5 type widely used in dental clinics were selected as the abutment screws of this study. In order to observe the surface roughness of abutment screw, FE-SEM (scanning electron microscope) and EDS (energy dispersive spectrometric) were used. The corrosion behavior of abutment screws have been researched by using A.C impedance test, and potentiodynamic test in 0.9% NaCl at 36.5±1℃. After electrochemical corrosion tests, the surface of each specimen were investigated by using FE-SEM.

The results were as follows:

1. The surface of type A and B showed severely machined defects, whereas, the surfaces of type C, D and E showed smoother surface than those of type A and B. 2. The abutment screws of 5 types were made of Ti(Cp-Ti) and Ti-6Al-4V alloy and were formed the large passive region in the potential of mouth environments. 3. From AC impedance test results, polarization resistance of smooth surface specimen was higher than that of rough surface one. The severe machined specimens showed the lower polarization resistance. 4. From the potentiodynamic test, the corrosion potential of smooth surface specimen was higher than that of rough surface one. Whereas, current density of smooth surface specimen in passive region was lower than that of rough surface one.