title: Bacterial adherence to tantalum versus commonly used orthopedic metallic implant materials.
abstract: OBJECTIVE
  Evaluation of bacterial adhesion to pure tantalum and tantalum-coated stainless steel versus commercially pure titanium, titanium alloy (Ti-6Al-4V), and grit-blasted and polished stainless steel.
  
  
  METHODS
  Experimental in vitro cell culture study using Staphylococcus aureus and Staphylococcus epidermidis to evaluate qualitatively and quantitatively bacterial adherence to metallic implants.
  
  
  METHODS
  A bacterial adhesion assay was performed by culturing S. aureus (ATCC 6538) and S. epidermidis (clinical isolate) for one hour with tantalum, tantalum-coated stainless steel, titanium, titanium alloy, grit-blasted and polished stainless steel metallic implant discs. Adhered living and dead bacteria were stained using a 2-color fluorescence assay. Adherence was then quantitatively evaluated by fluorescence microscopy and digital image processing. Qualitative adherence of the bacteria was analyzed with a scanning electron microscope. The quantitative data were related to the implant surface roughness (Pa-value) as measured by confocal laser scanning microscopy.
  
  
  RESULTS
  Bacterial adherence of S. aureus varied significantly (p = 0.0035) with the type of metallic implant. Pure tantalum presented with significantly (p < 0.05) lower S. aureus adhesion compared to titanium alloy, polished stainless steel, and tantalum-coated stainless steel. Furthermore, pure tantalum had a lower, though not significantly, adhesion than commercially pure titanium and grit-blasted stainless steel. Additionally, there was a significantly higher S. aureus adherence to titanium alloy than to commercially pure titanium (p = 0.014). S. epidermidis adherence was not significantly different among the tested materials. There was no statistically significant correlation between bacterial adherence and surface roughness of the tested implants.
  
  
  CONCLUSIONS
  Pure tantalum presents with a lower or similar S. aureus and S. epidermidis adhesion when compared with commonly used materials in orthopedic implants.
  
  
  CONCLUSIONS
  Because bacterial adhesion is an important predisposing factor in the development of clinical implant infection, tantalum may offer benefits as an adjunct or alternative material compared with current materials commonly used for orthopedic implants.
authors.affiliation: Chirurgische Klinik und Poliklinik, BG-Kliniken Bergmannsheil, Ruhr-Universität Bochum, Germany. thomas.a.schildhauer@ruhr-uni-bochum.de
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Schildhauer
authors.forename: Bruce
authors.initials: B
authors.lastname: Robie
authors.forename: Gert
authors.initials: G
authors.lastname: Muhr
authors.forename: Manfred
authors.initials: M
authors.lastname: Köller
mesh_terms: D000497:Alloys; D001422:Bacterial Adhesion; D019637:Orthopedic Procedures; D019736:Prostheses and Implants; D013193:Stainless Steel; D013211:Staphylococcus aureus / Q000502:physiology*; D013212:Staphylococcus epidermidis / Q000502:physiology*; D013499:Surface Properties; D013635:Tantalum
chemical_list: D000497:Alloys; D013193:Stainless Steel; D013635:Tantalum