title: In Vitro Investigation of the Effect of Oral Bacteria in the Surface Oxidation of Dental Implants.
abstract: BACKGROUND
  Bacteria are major contributors to the rising number of dental implant failures. Inflammation secondary to bacterial colonization and bacterial biofilm is a major etiological factor associated with early and late implant failure (peri-implantitis). Even though there is a strong association between bacteria and bacterial biofilm and failure of dental implants, their effect on the surface of implants is yet not clear.
  
  
  OBJECTIVE
  To develop and establish an in vitro testing methodology to investigate the effect of early planktonic bacterial colonization on the surface of dental implants for a period of 60 days.
  
  
  METHODS
  Commercial dental implants were immersed in bacterial (Streptococcus mutans in brain-heart infusion broth) and control (broth only) media. Immersion testing was performed for a period of 60 days. During testing, optical density and pH of immersion media were monitored. The implant surface was surveyed with different microscopy techniques post-immersion. Metal ion release in solution was detected with an electrochemical impedance spectroscopy sensor platform called metal ion electrochemical biosensor (MIEB).
  
  
  RESULTS
  Bacteria grew in the implant-containing medium and provided a sustained acidic environment. Implants immersed in bacterial culture displayed various corrosion features, including surface discoloration, deformation of rough and smooth interfaces, pitting attack, and severe surface rusting. The surface features were confirmed by microscopic techniques, and metal particle generation was detected by the MIEB.
  
  
  CONCLUSIONS
  Implant surface oxidation occurred in bacteria-containing medium even at early stages of immersion (2 days). The incremental corrosion resulted in dissolution of metal ions and debris into the testing solution. Dissolution of metal ions and particles in the oral environment can trigger or contribute to the development of peri-implantitis at later stages.
authors.affiliation: Department of Bioengineering, University of Texas at Dallas, Richardson, TX, USA.
authors.forename: Sathyanarayanan
authors.initials: S
authors.lastname: Sridhar
authors.affiliation: private practice of periodontics, Dallas, TX, USA.
authors.forename: Thomas G
authors.initials: TG
authors.lastname: Wilson
authors.affiliation: Department of Molecular and Cell Biology, University of Texas at Dallas, Richardson, TX, USA.
authors.forename: Kelli L
authors.initials: KL
authors.lastname: Palmer
authors.affiliation: private practice of periodontics, Dallas, TX, USA.
authors.forename: Pilar
authors.initials: P
authors.lastname: Valderrama
authors.affiliation: Section of Tribology, Department of Orthopedic Surgery, Rush University Medical Center, Chicago, IL, USA.
authors.forename: Mathew T
authors.initials: MT
authors.lastname: Mathew
authors.affiliation: Department of Bioengineering, University of Texas at Dallas, Richardson, TX, USA.
authors.forename: Shalini
authors.initials: S
authors.lastname: Prasad
authors.affiliation: Department of Bioengineering, University of Texas at Dallas, Richardson, TX, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Jacobs
authors.affiliation: Department of Bioengineering, University of Texas at Dallas, Richardson, TX, USA.
authors.forename: Izabelle M
authors.initials: IM
authors.lastname: Gindri
authors.affiliation: Department of Bioengineering, University of Texas at Dallas, Richardson, TX, USA.
authors.forename: Danieli C
authors.initials: DC
authors.lastname: Rodrigues
mesh_terms: D003343:Corrosion; D043302:Cultured Milk Products; D015921:Dental Implants / Q000382:microbiology*; D066298:In Vitro Techniques; D010084:Oxidation-Reduction; D013295:Streptococcus mutans / Q000378:metabolism*; D013499:Surface Properties
chemical_list: D015921:Dental Implants
keywords: bacterial adhesion; biomaterials; implant surface; peri-implantitis