title: Short-term bone response to titanium implants coated with thin radiofrequent magnetron-sputtered hydroxyapatite in rabbits.
abstract: BACKGROUND
  It has been suggested that calcium phosphate (CaP) coatings initiate faster bone growth around implants. A major concern about the viable use of these coatings has been their biologic performance related to the coating characteristics.
  
  
  OBJECTIVE
  The purpose of this study was to investigate the early bone response to micron- and submicron-thick hydroxyapatite (HA) coatings in cortical and trabecular bone.
  
  
  METHODS
  CaP coatings were manufactured by magnetron sputtering. Heat treatment was subsequently used to increase the crystallinity of the coatings. Coatings were characterized by x-ray diffraction, Fourier transform infrared spectroscopy, inductively coupled plasma optical emission spectroscopy (ICP-OES), and stylus profilometry. Four types of CaP-coated implants were used (0.1 microm and 2.0 microm amorphous; 0.1 microm and 2.0 microm crystalline); uncoated machined commercially pure titanium implants served as controls. Four hundred eighty implants were randomly placed in 60 rabbits. Ten animals were followed up for 1 week, 10 for 3 weeks, and 40 for 6 weeks. The bone response was histomorphometrically evaluated.
  
  
  RESULTS
  Coatings with a CaP ratio very close to that of HA were produced. Crystalline coatings significantly improved the early bone-implant contact whereas the amorphous-coated implants behaved similarly to uncoated titanium.
  
  
  CONCLUSIONS
  Crystalline CaP coatings 100 nm thick on titanium implants elicited an improved early bone response compared with that of uncoated titanium implants. No further improvement in the bone response was observed with 2 microm coatings.
authors.affiliation: Department of Biomaterials, Sahlgrenska Academy at Gothenburg University, Gothenburg, Sweden.
authors.forename: Shams
authors.initials: S
authors.lastname: Mohammadi
authors.forename: Marco
authors.initials: M
authors.lastname: Esposito
authors.forename: Jan
authors.initials: J
authors.lastname: Hall
authors.forename: Lena
authors.initials: L
authors.lastname: Emanuelsson
authors.forename: Anatol
authors.initials: A
authors.lastname: Krozer
authors.forename: Peter
authors.initials: P
authors.lastname: Thomsen
mesh_terms: D000818:Animals; D020099:Coated Materials, Biocompatible; D018360:Crystallography, X-Ray; D003758:Dental Implantation, Endosseous; D015921:Dental Implants; D017886:Durapatite; D005260:Female; D005269:Femur; D020007:Implants, Experimental; D016348:Osseointegration; D011817:Rabbits; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties; D013977:Tibia; D014025:Titanium
chemical_list: D020099:Coated Materials, Biocompatible; D015921:Dental Implants; D017886:Durapatite; D014025:Titanium