title: Evaluation of alumina toughened zirconia implants with a sintered, moderately rough surface: An experiment in the rat.
abstract: OBJECTIVE
  Alumina toughened zirconia (ATZ) is more fracture resistant than unmodified zirconia and has been shown to be a viable substrate for the growth of osteoblasts. In this study, we examined the histological and biomechanical behavior of moderately roughened ATZ implants in rat femoral bone.
  
  
  METHODS
  Miniature implants made of ATZ with pore-building polymers sintered onto the surface and electrochemically anodized titanium (TiUnite®) were placed into the femurs of Sprague-Dawley rats. Implant surface topography was analyzed by 3D laserscan measurements and scanning electron microscopy (SEM). After a healing period of 14 and 28 days, respectively, histologic and biomechanical testing was performed.
  
  
  RESULTS
  Under the SEM, the TiUnite® surface could be clearly distinguished from the ATZ surface, but 3D laserscan measurements indicated a moderately rough surface topography for both, TiUnite® (Sa=1.31μm) and ATZ (Sa=1.51μm). The mean mineralized bone-to-implant contact showed the highest values after 14 and 28 days for TiUnite® (58%/75%) as compared to ATZ (24%/41%). The push-in values after a healing period of 14 and 28 days, respectively, increased from 20N to 39N for TiUnite® and from 10N to 25N for ATZ.
  
  
  CONCLUSIONS
  Our findings suggest that the moderately roughened ATZ implant surface is well accepted by rat bone tissue. However, compared to titanium, the osseointegration-process of ATZ seems to proceed more slowly in that early phase of implant integration.
authors.affiliation: Department of Prosthodontics, School of Dentistry, University Hospital Freiburg, Freiburg, Germany.
authors.forename: Ralf J
authors.initials: RJ
authors.lastname: Kohal
authors.affiliation: Department of Prosthodontics, School of Dentistry, University Hospital Freiburg, Freiburg, Germany.
authors.forename: Maria
authors.initials: M
authors.lastname: Bächle
authors.affiliation: Fraunhofer Institute for Mechanics of Materials IWM, Freiburg, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Renz
authors.affiliation: Department of Prosthodontics, School of Dentistry, University Hospital Freiburg, Freiburg, Germany. Electronic address: frank.butz@uniklinik-freiburg.de.
authors.forename: Frank
authors.initials: F
authors.lastname: Butz
mesh_terms: D000537:Aluminum Oxide / Q000737:chemistry*; D000818:Animals; D015921:Dental Implants; D005269:Femur / Q000601:surgery*; D021621:Imaging, Three-Dimensional; D020007:Implants, Experimental; D008297:Male; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D016348:Osseointegration / Q000502:physiology*; D011108:Polymers / Q000737:chemistry; D051381:Rats; D017207:Rats, Sprague-Dawley; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry; D015040:Zirconium / Q000737:chemistry*
chemical_list: D015921:Dental Implants; D011108:Polymers; D015040:Zirconium; D014025:Titanium; D000537:Aluminum Oxide; C028541:zirconium oxide
keywords: Alumina toughened zirconia; Cell-culture study; Dental implants; Histomorphometry; Push-in test; Surface topography