title: An electrochemical investigation of TMJ implant metal alloys in an artificial joint fluid environment: the influence of pH variation.
abstract: OBJECTIVE
  To investigate the corrosion behaviour of commonly used TMJ implants alloys (CoCrMo and Ti6Al4V) under simulated physiological conditions.
  
  
  METHODS
  Corrosion behaviour was evaluated using standard electrochemical corrosion techniques and galvanic corrosion techniques as per ASTM standards. Standard electrochemical tests (E(corr), I(corr), R(p) and C(f)) were conducted in bovine calf serum (BCS), as a function of alloys type and different pHs. Galvanic corrosion tests were conducted in BCS at a pH of 7.6. Alloy surfaces were characterized using white-light interferometry (WLI) and scanning electron microscopy (SEM).
  
  
  RESULTS
  The potentiodynamic test results exhibited the enhanced passive layer growth and a better corrosion resistance of Ti6Al4V compared to CoCrMo. Electrochemical impedance spectroscopy measurements demonstrated the influence of protein as a function of pH on corrosion mechanisms/kinetics. Galvanic coupling was not a major contributor to corrosion. SEM and WLI images demonstrated a significantly higher in surface roughness in CoCrMo after corrosion.
  
  
  CONCLUSIONS
  The results of this study suggest that Ti6Al4V shows superior corrosion behaviour to CoCrMo due to its strong passive layer, simulated joint fluid components can affect the electrochemical nature of the metal/electrolyte interface as a function of pH, and the galvanic effect of coupling CoCrMo and Ti6Al4V in a single joint is weak.
authors.affiliation: University of Illinois at Chicago College of Dentistry, Department of Restorative Dentistry (Head: Dr. Stephen Campbell, DDS, MMSc), 801 S. Paulina Ave, Chicago, IL 60612, USA; Rush University Medical Center, Department of Orthopedics (Head: Dr. Joshua Jacobs, MD), 1611 W. Harrison St., Chicago, IL 60612, USA.
authors.forename: Dmitry
authors.initials: D
authors.lastname: Royhman
authors.affiliation: Rush University Medical Center, Department of Orthopedics (Head: Dr. Joshua Jacobs, MD), 1611 W. Harrison St., Chicago, IL 60612, USA.
authors.forename: Rashmi
authors.initials: R
authors.lastname: Radhakrishnan
authors.affiliation: University of Illinois at Chicago College of Dentistry, Department of Restorative Dentistry (Head: Dr. Stephen Campbell, DDS, MMSc), 801 S. Paulina Ave, Chicago, IL 60612, USA.
authors.forename: Judy Chia-Chun
authors.initials: JC
authors.lastname: Yuan
authors.affiliation: University of Illinois at Chicago College of Dentistry, Department of Restorative Dentistry (Head: Dr. Stephen Campbell, DDS, MMSc), 801 S. Paulina Ave, Chicago, IL 60612, USA; Rush University Medical Center, Department of Orthopedics (Head: Dr. Joshua Jacobs, MD), 1611 W. Harrison St., Chicago, IL 60612, USA.
authors.forename: Mathew T
authors.initials: MT
authors.lastname: Mathew
authors.affiliation: Rush University Medical Center, Department of Orthopedics (Head: Dr. Joshua Jacobs, MD), 1611 W. Harrison St., Chicago, IL 60612, USA; TMJ Concepts, 2233 Knoll Drive, Ventura, CA 93003, USA.
authors.forename: Louis G
authors.initials: LG
authors.lastname: Mercuri
authors.affiliation: University of Illinois at Chicago College of Dentistry, Department of Restorative Dentistry (Head: Dr. Stephen Campbell, DDS, MMSc), 801 S. Paulina Ave, Chicago, IL 60612, USA. Electronic address: csukotjo@uic.edu.
authors.forename: Cortino
authors.initials: C
authors.lastname: Sukotjo
mesh_terms: D000497:Alloys / Q000737:chemistry*; D000818:Animals; D001769:Blood; D001798:Blood Proteins / Q000737:chemistry; D002417:Cattle; D002858:Chromium Alloys / Q000737:chemistry; D003343:Corrosion; D058266:Dielectric Spectroscopy; D025802:Electric Capacitance; D017097:Electric Impedance; D055664:Electrochemical Techniques; D006863:Hydrogen-Ion Concentration; D007368:Interferometry; D007595:Joint Prosthesis; D008027:Light; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D011199:Potentiometry; D011474:Prosthesis Design; D013499:Surface Properties; D013696:Temperature; D013704:Temporomandibular Joint; D013997:Time Factors; D014025:Titanium / Q000737:chemistry
chemical_list: D000497:Alloys; D001798:Blood Proteins; D002858:Chromium Alloys; C031462:titanium alloy (TiAl6V4); D014025:Titanium
keywords: Alloy CoCrMo alloy; Artificial joint fluid; Corrosion; Electrochemistry; TMJ; Titanium