Corrosion of machined titanium dental implants under inflammatory conditions

Abstract

The effects of hyperglycemia, altered cell function, or inflammatory mediators on implant corrosion are not well studied; yet, these effects are critical to implant biocompatibility and osseointegration. Because implant placement is burgeoning, patients with medically compromising systemic conditions such as diabetes are increasingly receiving implants, and the role of other inflammatory diseases on implant corrosion also needs investigation. In the current study, the corrosion properties of commercially available, machined titanium implants were studied in blood, cultures of monocytic cells, and solutions containing elevated dextrose concentrations. Implant corrosion was estimated by open circuit potentials, linear polarization resistance, and electrical impedance spectroscopy (EIS) for 26 h. In selected samples, THP1 monocytic cells were activated for 2 h with Lipopolysaccharide prior to implant exposure, and IL-1beta secretion was measured to assess the affect of the implants on monocyte activation. Implants under conditions of inflammatory stress exhibited more negative E(corr) values, suggesting an increased potential for corrosion. Linear polarization measurements detected increased corrosion rates in the presence of elevated dextrose conditions over PBS conditions. EIS measurements suggested that implants underwent surface passivation reactions that may have limited corrosion over the short term of this test. This result was supported by cyclic polarization tests. IL-1beta secretion was not altered under conditions of corrosion or implant exposure. The results suggest that inflammatory stress and hyperglycemia may increase the corrosion of dental endosseous titanium-based implants, but that longer, more aggressive electrochemical conditions may be necessary to fully assess these effects.

Effects of Dextrose and Lipopolysaccharide on the Corrosion Behavior of a Ti-6Al-4V Alloy with a Smooth Surface or Treated with Double-Acid-Etching

“…The higher the concentration of the combined DEX-LPS, the lower the corrosion potential of the smooth Ti. The reduced values (more electronegative) of E corr suggest that the smooth Ti provides a less stable surface [21], [22] that may be a result of decreased surface passivity. A previous study related the passivity to the thickening of the oxide/hydroxide layer in the titanium/electrolyte interface [21].…”

“…Messer et al [22] evaluated the electrochemical behavior of commercially pure Ti implants (cpTi) in inflammatory and hyperglycemic conditions. The corrosion potential shifted to noble values at high concentrations of dextrose (15 mM) at the same concentration used in this study, as a function of monocyte cultures and blood cells.…”

“…This indicates that the resistance of the material increased with increasing concentrations of dextrose, showing similar R p values at 15 mM of dextrose concentration when compared with SBF (control), thus protecting the surface of the material. It is believed that the saccharides and proteins on dental implant surfaces can enhance the corrosion resistance of the Ti in accordance with the binding affinity to the specific proteins and cause the release of metal ions from the surface of the material to the peri-implant region [21], [22]. However, the interaction of the metals and proteins, blood cells, and their products to promote corrosion depends on several factors, such as roughness, surface charge, material composition, and the affinity agent molecules of the metal [49], and may even protect the surface of the Ti by protein absorption through the electrolyte [21].…”

Response of monocyte-derived dendritic cells to rapidly solidified nickel-titanium ribbons with shape memory properties

“…This is because Ti is more readily oxidised than Ni, so the biologically inert Ti-oxide layer and extracellularderived calcium-phosphate layer on the Ni-Ti surface prevent the release of Ni (Es-Souni and Fischer-Brandies, 2005). However, since Ti-oxide is a very brittle ceramic, it can be damaged during dynamic mechanical loading (Peitsch et al, 2007) or under infl ammatory conditions (Messer et al, 2009), leading inevitably to the initiation of corrosion and increased release of Ni ions, causing local or systematic adverse health effects (Das et al, 2008). This could lead to necrotic and apoptotic changes of the tissue surrounding the implant (Bogdanski et al, 2004), increased expression of infl ammatory mediators such as tumour necrosis factor-alpha (TNF-α) and interleukin 6 (IL-6) and reduced proliferation of cells near the implant (Es-Souni and Fischer-Brandies, 2007).…”

Bioactivity and corrosion properties of novel coatings containing strontium by micro-arc oxidation

“…Implants made of titanium materials also release metal ions into the body. Messer et al [23] exposed titanium implants to several solutions, and found that they had a risk of corrosion. Hence, coatings are necessary to protect the implants in a body environment.…”