Dynamic Action of Mouthwashes Affects the Electrochemical Behavior of Ti6Al4V Alloy

Abstract

This study investigated the electrochemical behavior of the Ti6Al4V alloy under the influence of dynamic action of mouthwashes. Ti6Al4V alloy disks (n = 5) were dynamically exposed to mouthwashes (0.12% chlorhexidine digluconate [CHX], cetylpyridinium chloride [CC], and hydrogen peroxide [HP]) by immersion 3 times a day for 1 min. Artificial saliva [AS] is a control solution. The electrochemical behavior of the Ti6Al4V (n = 5) was tested at the baseline, and after 7 and 14 days of mouthwashes dynamic action. Surfaces characteristics were investigated using scanning electron microscopy (SEM), energy-dispersive spectroscopy, surface roughness, and Vickers microhardness. CC had the highest values of polarization resistance (Rp), and CHX reduced the capacitance values (Q) compared to the other groups (p < 0.05). HP generated the lowest Rp values in all periods, and the highest Q values after 14 days immersion (p < 0.05). CC and CHX did not alter the alloy potentiodynamic curves when compared to AS. HP increased the corrosion and passivation current densities, and the corrosion rate in relation to the other groups (p < 0.05). SEM micrographs showed minors surface changes with the presence of pitting corrosion for HP. No differences were found for roughness and microhardness after all immersion periods (p > 0.05). Dynamic mouthwash simulation with HP impairs the corrosion stability of Ti6Al4V alloy, and CC presents the greatest electrochemical stability over time. Our data shed light on how the dynamic action of mouthwashes affects the Ti electrochemical behavior aiming at ensuring a safer indication for patients receiving dental implant.