title: Histological evaluation of novel ossicular chain replacement prostheses: an animal study in rabbits.
abstract: CONCLUSIONS
  The improved biocompatibility of Bioverit II coated with a nanostructured surface shows promising qualities for use in human reconstructive middle ear surgery. In the case of chitosan-hydroxyapatite composite prostheses, further investigations regarding composition of the material, degree of purity and design are necessary before clinical application.
  
  
  OBJECTIVE
  The selection of optimal materials for reconstructive middle ear surgery continues to be a problem. In the present study novel materials were tested as total ossicular replacement prostheses (TORPs) in an animal model.
  
  
  METHODS
  Bioverit II coated with a nanostructured surface and chitosan-hydroxyapatite composites were placed in the middle ear of 40 rabbits. Uncoated Bioverit II was used as control. After an implantation period of 28, 84 or 300 days petrous bones were extracted, embedded in epoxy resin and examined by light microscopy.
  
  
  RESULTS
  Uncoated and coated Bioverit prostheses revealed a mucosal coverage and a little osseogenic response after 28 days. The results of the coated Bioverit prostheses slightly surpassed those of the plain prostheses. Chitosan-hydroxyapatite composite prostheses were mostly found to be dislocated after 28 days. Formations of granulation tissue and fibrotic capsules were observed around these implants. This reaction could be caused by the instability of the composite material or may be due to impurities present in the chitosan.
authors.affiliation: Department of Otolaryngology, Medical University of Hannover, Germany.
authors.forename: Christina
authors.initials: C
authors.lastname: Turck
authors.forename: Gudrun
authors.initials: G
authors.lastname: Brandes
authors.forename: Ilka
authors.initials: I
authors.lastname: Krueger
authors.forename: Peter
authors.initials: P
authors.lastname: Behrens
authors.forename: Hamidreza
authors.initials: H
authors.lastname: Mojallal
authors.forename: Thomas
authors.initials: T
authors.lastname: Lenarz
authors.forename: Martin
authors.initials: M
authors.lastname: Stieve
mesh_terms: D000818:Animals; D001672:Biocompatible Materials; D002516:Ceramics; D048271:Chitosan; D020099:Coated Materials, Biocompatible; D003776:Dental Porcelain; D004195:Disease Models, Animal; D017886:Durapatite; D004427:Ear Diseases / Q000473:pathology / Q000601:surgery*; D004432:Ear, Middle / Q000473:pathology* / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D006097:Granulation Tissue / Q000473:pathology; D009092:Mucous Membrane / Q000473:pathology; D009998:Ossicular Prosthesis; D019933:Ossicular Replacement / Q000295:instrumentation*; D011474:Prosthesis Design; D011817:Rabbits; D016896:Treatment Outcome
chemical_list: D001672:Biocompatible Materials; C067324:Bioverit; D020099:Coated Materials, Biocompatible; D003776:Dental Porcelain; D048271:Chitosan; D017886:Durapatite