title: Tissue response to expanded polytetrafluoroethylene and silicone implants in a rabbit model.
abstract: BACKGROUND
  Expanded polytetrafluoroethylene (ePTFE) and silicone are safe and relatively biocompatible materials.
  
  
  OBJECTIVE
  To compare, using multiple histologic parameters, the tissue response to a standard silicone soft tissue implant with the response to a modified ePTFE implant. The modified form of ePTFE is reinforced with fluorinated ethylene propylene (FEPRePTFE), which provides increased pliability and material integrity.
  
  
  METHODS
  The implants were placed into a subperiosteal pocket over the skull of adult New Zealand white rabbits. At 7, 30, and 90 days after implantation, en bloc tissue specimens, including skin, implants, surrounding soft tissue, and underlying bone were harvested for gross and histologic evaluation.
  
  
  METHODS
  The tissue response to the implants was assessed with respect to the number of foreign body giant cells present, the thickness of the fibrous capsule, and the general inflammatory response (n = 6 for each implant at each evaluation period).
  
  
  RESULTS
  There were no cases of rejection, extrusion, or infection. The silicone implants elicited a significantly thicker capsule and less neovascularization (P<.05).
  
  
  CONCLUSIONS
  The FEPRePTFE demonstrated a favorable tissue response when compared with silicone, particularly in regard to capsule thickness and vascular ingrowth.
authors.affiliation: Division of Otolaryngology, Albany Medical Center, 47 New Scotland Ave, Albany, NY 12208, USA.
authors.forename: Rami K
authors.initials: RK
authors.lastname: Batniji
authors.forename: Joseph L
authors.initials: JL
authors.lastname: Hutchison
authors.forename: Ravi
authors.initials: R
authors.lastname: Dahiya
authors.forename: Samuel L
authors.initials: SL
authors.lastname: Lam
authors.forename: Edwin F
authors.initials: EF
authors.lastname: Williams
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000009:adverse effects* / Q000627:therapeutic use; D005260:Female; D005549:Foreign-Body Reaction / Q000473:pathology; D008422:Materials Testing; D023421:Models, Animal; D011138:Polytetrafluoroethylene / Q000009:adverse effects* / Q000031:analogs & derivatives* / Q000627:therapeutic use; D019736:Prostheses and Implants / Q000009:adverse effects*; D011817:Rabbits; D012828:Silicones / Q000009:adverse effects* / Q000627:therapeutic use; D012886:Skull; D005465:Fluorocarbon Polymers
chemical_list: D001672:Biocompatible Materials; D011138:Polytetrafluoroethylene; D012828:Silicones; C096305:fluorinated ethylene propylene; D005465:Fluorocarbon Polymers