치과 임플란트 고정체의 제조 공정이 표면특성에 미치는 영향

Abstract

Titanium and Ti-6Al-4V alloy are use in the medical field, for dental implants, Ti and Ti-6Al-4V alloy present the advantage of great compatibility with body fluids. The adverse body reaction to the implant is due to the metallic ions released by the implant, the amount of ions released depending on the corrosion rate of the implant. This study was performed to investigate the effects of manufacturing process on the surface characteristics of dental implant was selected with 5 steps by cleaning, surface treatment and sterilization with same size and screw structure. The 1st step machined surface, 2nd step cleaned by thinner and prosol solution, 3th step surface treated by RBM method, 4th step cleaned and dried, 5th step sterilized by gamma ray. Estimation of electrochemical behavior of 5 steps of dental implant have been evaluated by using electrochemical methods. These specimens were used for corrosion test in 0.9 % NaCl solution at 36.5±1℃. The electrochemical stability was investigated using potentiostat (EG&G Co, 263A). The corrosion surface were observed using scanning electron microscopy (SEM). The surface morphology were observed using scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDX).

The results were as follows:

1. From the results of SEM micrographs, sample of step 5 was observed very clean surface than sample of step 3. The sample of step 5 was observed rough surface with shape of low ridge and valley.

2. From the results of potentiodynamic test in 0.9% NaCl solution, step 5 of implant fixture with RBM treatment, clean and gamma sterilization was shown the lowest value of corrosion current density. Especially, step 3 of implant fixture with RBM treatment was presented the lowest value of corrosion resistance and the highest value of corrosion current density.

3. From the results of AC impedance test, step 3 of sample was presented lower value of polarization resistance than other samples.

In conclusion, step 5 of implant fixture with RBM treatment, clean and gamma sterilization was observed higher corrosion resistance, it depends on the step of manufacturing process by form the stable TiO2 passive film.