Electrochemical behavior of additively manufactured patterned titanium alloys under simulated normal, inflammatory, and severe inflammatory conditions

Abstract

The electrochemical behavior of a biomaterial surface in local conditions is a significant factor affecting the success of the implant placement. This is of a particular importance of metallic biomaterials which can undergo oxidation, corrosion and subsequent degradation. This study reports new data on the electrochemical behavior of additively manufactured (AM) patterned titanium alloys, analyzed after 1 and 12 h immersion in three different media mimicking normal, inflammatory and severe inflammatory conditions. Polarization study showed that corrosion resistance increases with increasing immersion time in all cases. It was found that in inflammatory condition a destructive effect on the passive layer's resistance was triggered by H2O2 whereas in severe inflammatory condition, albumin, lactate, and H2O2 all have a synergistic effect towards decreasing the corrosion resistance of patterned titanium layers. Electrochemical impedance data suggests that in the severe inflammatory condition the charged albumins are attracting to the localized pitting areas, changing diffusion transport of corrosive species at the interface of the metal/passive layer. The electrochemical tests also proven that laser-assisted patterned titanium alloys surfaces have an improved corrosion resistance in simulated solutions compared to untreated titanium of the same composition. It is suggested that new surface topography and wettability are also positive factors contributing to this improved corrosion performance in patterned specimens.