Corrosion and Micromorphological Analysis of Temporary Stainless Steel and Titanium Alloy Anchorage Devices

Abstract

The aim of this study was to compare the surface micromorphology and corrosion resistance of diferent temporary anchoragedevices (TADs) composed of titanium alloy (SIN®) and stainless steel (DAT Steel® and Bio Ray®). Ten samples of eachTAD were submitted to qualitative analyses using energy-dispersive and scanning electronic microscopy before and afterimmersion in artifcial saliva (1500 ppm of fuoride) for 30 days. The chemical analysis was done by X-ray fuorescence,and the corrosion tests were performed by electrochemical means (open circuit potential—OCP, potentiostat, and electrochemical impedance spectroscopy—EIS, using anodic potentiodynamic polarization curves). Passive flm resistance (PFR)and corrosion current were established. The corrosion rate was determined by the mass loss test. Greater smoothness andfewer machining defects were observed for the stainless steel TAD before artifcial saliva immersion. Comparatively, highercorrosion resistance was found for titanium alloy TAD after immersion in saliva. There was no release of ions into the TADwhen immersed in artifcial saliva. ANOVA and Tukey tests showed that OCP (V) was signifcantly lower for the titaniumalloy TAD (p=0.030) than the stainless steel brands. Epite (V) and Epite−OCP (V) were signifcantly higher for the titaniumalloy TAD (p=0.0009 and p=0.0005, respectively). Stainless steel TADs presented lower roughness surface than titaniumalloy TAD, although the latter presented higher corrosion resistance than the former