Electrochemical Behavior of Ti6Al4V Alloy Used in Dental Implants Immersed in Streptococcus gordonii and Fusobacterium nucleatum Solutions

Abstract

The titanium alloy, Ti6Al4V, is used in dentistry for dental implants because of its excellent resistance to corrosion and its high biocompatibility. However, periimplantitis is considered the main reason for treatment failure. The Ti6Al4V alloy was used to study the corrosion behavior for dental implant applications, using an experimental arrangement of three electrodes with the bacteria Streptococcus gordonii and Fusobacterium nucleatum, in addition to Ringer’s lactate as electrolytes, at 37 °C and a pH of 5.6. Their electrochemical behavior was studied by open circuit potential (OCP) and cyclic potentiodynamic polarization (CPP) according to ASTM G3-14 and ASTM G61-11, respectively. Scanning electron microscopy (SEM) was employed to determine the morphology of the alloy studied. An experimental model, in situ, was established with the bacteria present in an oral environment to understand the electrochemical behavior of the alloy used in dental implants. The greatest corrosion in Ti6Al4V alloy was produced by the medium that contained the bacterium Streptococcus gordonii, which is considered a primary colonizer. In addition, the Ti6Al4V alloy presented uniform corrosion in the three solutions at the different exposure times showing a negative hysteresis in CPP.

Novel Coatings to Minimize Corrosion of Titanium in Oral Biofilm

“…The sulfides produced by P. gingivalis did not cause titanium corrosion for 14 days. De la Garza-Ramos [ 24 ] showed a greater corrosion rate in Ti6Al4V alloy at 4 days of exposure by the medium that contains the Streptococcus gordonii .…”

“…The coatings may have decreased the surface roughness by covering and filling remaining scratches and irregularities of the surface. De la Garza-Ramos [ 24 ] indicated that morphology does not present localized corrosion in the Ti6Al4V alloy by SEM observations in contact with Fusobacterium nucleatum and Streptococcus gordonii .…”

Bio-Tribocorrosion of Titanium Dental Implants and Its Toxicological Implications: A Scoping Review

“…Both early (e.g., S. mutans, Streptococccus gordonii (S. gordonii), and Lactobacilli) and late (e.g., P. gingivalis) colonizers and the bridging organisms (e.g., Fusobacterium nucleatum (F. nucleatum)) of the oral biofilm cause corrosion [16,[46][47][48].…”

“…Contrarily, exposure of Ti6Al4V alloy to the electrolyte solution containing S. gordonii with or without F. nucleatum showed a reduced corrosion rate due to the formation of a passive TiO 2 film by these bacteria. However, at 96 hours, the electrochemical potential of the solution of F. nucleatum with S. gordonii was altered with an increased tendency towards corrosion [47].…”

“…e F. nucleatum and Prevotella melaninogenica are Gram-negative anaerobic sulphateproducing pathogens that produce butyric acid, carbon dioxide, and hydrogen during the enzymatic degradation of saccharides and increase the Ti corrosion. Its corrosion rate is proportional to the S. gordonii levels [47].…”