title: Biomechanical and histological behavior of zirconia implants: an experiment in the rat.
abstract: OBJECTIVE
  This study aimed at evaluating the integration of zirconia implants in a rat femur model.
  
  
  METHODS
  Zirconia implants with two distinct surface topographies were compared with titanium implants with similar topographies. Titanium and zirconia implants were placed into the femurs of 42 male Sprague-Dawley rats. Four groups of implants were utilized: machined zirconia implants, zirconia implants with a rough surface, machined titanium implants, and titanium implants with an electrochemically roughened surface. After a healing period of 28 days, the load-bearing capacity between the bone and the implant surface was evaluated by a push-in test. Additionally, after a healing period of 14 and 28 days, respectively, bone tissue specimens containing the implants were processed and histologically analyzed.
  
  
  RESULTS
  The mean mineralized bone-to-implant contact showed the highest values after 14 and 28 days for the rough surfaces (titanium: 36%/45%; zirconia: 45%/59%). Also, the push-in test showed higher values for the textured implant surfaces, with no statistical significance between titanium (34 N) and zirconia (45.8 N).
  
  
  CONCLUSIONS
  Within the limits of the animal investigation presented, it was concluded that all tested zirconia and titanium implant surfaces were biocompatible and osseoconductive. The presented surface modification of zirconia implants showed no difference regarding the histological and biomechanical results compared with an established electrochemically modified titanium implant surface.
authors.affiliation: Department of Prosthodontics, University Hospital Freiburg, School of Dentistry, Freiburg, Germany. ralf.kohal@uniklinik-freiburg.de
authors.forename: Ralf J
authors.initials: RJ
authors.lastname: Kohal
authors.forename: Martin
authors.initials: M
authors.lastname: Wolkewitz
authors.forename: Marc
authors.initials: M
authors.lastname: Hinze
authors.forename: Jung-Suk
authors.initials: JS
authors.lastname: Han
authors.forename: Maria
authors.initials: M
authors.lastname: Bächle
authors.forename: Frank
authors.initials: F
authors.lastname: Butz
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry; D001696:Biomechanical Phenomena; D001861:Bone Regeneration / Q000502:physiology; D003722:Dental Alloys / Q000737:chemistry; D003758:Dental Implantation, Endosseous / Q000379:methods*; D015921:Dental Implants; D005269:Femur / Q000033:anatomy & histology* / Q000601:surgery; D008297:Male; D016348:Osseointegration / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013499:Surface Properties; D014025:Titanium; D015040:Zirconium
chemical_list: D001672:Biocompatible Materials; D003722:Dental Alloys; D015921:Dental Implants; D015040:Zirconium; D014025:Titanium; C028541:zirconium oxide