Effects of Biological Factors on the Repassivation Current of Titanium

Abstract

The repassivation current of titanium was measured by a newly designed electrochemical cell that can bare a new metal surface momentarily for the determination of the effects of biological factors such as dissolved oxygen, inorganic ions, amino acids, and proteins, on time transient of repassivation current. For this purpose, saline with various concentrations of dissolved oxygen and Hanks' solution with and without amino acids and proteins were employed as electrolytes. Estimated peak current densities and total charges during repassivation were used for the evaluation of reppasivation current. As a result, dissolved oxygen did not influence the repassivation reaction of titanium. Inorganic ions and proteins accelerated the repassivation, while some amino acids delayed it. If these factors are combined, it is important to reveal which factor governs the reaction. Unfortunately, that problem could not be revealed by this study. The above findings may apply to the dissolution amount of metal ion from depassivated titanium in the human body.