title: Enhanced implant integration with hierarchically structured implants: a pilot study in rabbits.
abstract: OBJECTIVE
  To investigate bone-to-implant bonding for some novel surface modifications with a hierarchic structure and to correlate the in vivo results with surface roughness parameters.
  
  
  METHODS
  Newly developed implants surfaces were tested in rabbits and compared with the commercially available OsseoSpeed™ (OS) implant. The blasted test samples were subjected to treatment in oxalic acid (AT-II), followed by subsequent etching in hydrofluoric acid (AT-I). Scanning electron microscopy and X-ray photoelectron spectroscopy were used to characterize the surface topography and chemical composition of the implants. Biomechanical testing after 6 weeks of healing was complemented with the quantification of fluorochromes and the results were subjected to a multivariate statistical analysis.
  
  
  RESULTS
  The results show, both with biomechanical- and with histomorphometrical tests, that the AT-I implants with different surface roughness at the micro (blasting), submicro (shallow cavities) and nanolevels (precipitates) have a greater bone tissue integration compared with the AT-II- and OS implants. The 2D bone-to-implant contact (BIC) data were in accordance with the 3D removal torque (RTQ) results even if the former were deduced from implants located in spongeous-type bone and the latter in cortical bone. The increase in RTQ values for the test samples AT-I and AT-II compared with the reference complies with the slightly higher S(a) values for these surfaces.
  
  
  CONCLUSIONS
  Using a combination of conventional methods with novel quantification of florochrome and multivariate analysis, the influence of surface roughness on different levels could be discriminated. The RTQ and BIC values show that the most hierarchical structure with submicro cavities and nanoscale precipitates possesses the most favourable osseointegration properties.
authors: Department of Prosthodontics/Dental Material Sciences, Sahlgrenska Academy, Institute of Odontology, University of Gothenburg, Gothenburg, Sweden. carina.johansson@odontologi.gu.se
authors: Carina B
authors: CB
authors: Johansson
authors: Christina
authors: C
authors: Gretzer
authors: Ryo
authors: R
authors: Jimbo
authors: Ingela
authors: I
authors: Mattisson
authors: Elisabet
authors: E
authors: Ahlberg
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D003758:Dental Implantation, Endosseous / Q000379:methods*; D015921:Dental Implants; D017267:Dental Prosthesis Design; D005269:Femur / Q000601:surgery*; D006858:Hydrofluoric Acid; D020007:Implants, Experimental; D008297:Male; D018613:Microscopy, Confocal; D008855:Microscopy, Electron, Scanning; D016348:Osseointegration; D019815:Oxalic Acid; D056951:Photoelectron Spectroscopy; D010865:Pilot Projects; D011817:Rabbits; D018709:Statistics, Nonparametric; D013499:Surface Properties; D014025:Titanium; D019415:Torque
chemical_list: D015921:Dental Implants; D019815:Oxalic Acid; D014025:Titanium; D006858:Hydrofluoric Acid