Avaliação da resistência à corrosão de mini-implantes ortodônticos submetidos à esterilização

Abstract

The aim of the present study was to evaluate the corrosion resistance and surface characteristics of new and sterilized orthodontic mini-implants. Were evaluated selfdrilling orthodontic mini-implants manufactured with Ti6AI4V alloy. The mini-implants were divided into 2 groups of 10 units: control group (control group) and test group (submitted to the sterilization process). A visual analysis of the surface of the thread of the mini-implants was carried through a scanning electron microscope (SEM) and an evaluation of the corrosion resistance, they were submitted to potentiodynamic cyclic polarization tests. From the polarization curves, the OCP (open circuit potential), ipp (primary passivation current) and Epp (primary passivation potential) values were extracted. The results showed that there was no statistically significant difference between the groups. The mini-implant thread surface analysis through MEV indicated that the surface morphology of the sterilized mini-implants was preserved, with no visible deformation, wear or corrosion characteristics. Only a miniimplant of the control group presented pite, the fact isolated and associated with imperfections of the manufacturing process. It has been concluded that the autoclaving process is not capable of altering a corrosion resistance or as superficial visual characteristics of the mini-implants.