title: Effects of zinc-substituted nano-hydroxyapatite coatings on bone integration with implant surfaces.
abstract: OBJECTIVE
  The purpose of this study was to investigate the effects of a zinc-substituted nano-hydroxyapatite (Zn-HA) coating, applied by an electrochemical process, on implant osseointegraton in a rabbit model.
  
  
  METHODS
  A Zn-HA coating or an HA coating was deposited using an electrochemical process. Surface morphology was examined using field-emission scanning electron microscopy. The crystal structure and chemical composition of the coatings were examined using an X-ray diffractometer (XRD) and Fourier transform infrared spectroscopy (FTIR). A total of 78 implants were inserted into femurs and tibias of rabbits. After two, four, and eight weeks, femurs and tibias were retrieved and prepared for histomorphometric evaluation and removal torque (RTQ) tests.
  
  
  RESULTS
  Rod-like HA crystals appeared on both implant surfaces. The dimensions of the Zn-HA crystals seemed to be smaller than those of HA. XRD patterns showed that the peaks of both coatings matched well with standard HA patterns. FTIR spectra showed that both coatings consisted of HA crystals. The Zn-HA coating significantly improved the bone area within all threads after four and eight weeks (P<0.05), the bone to implant contact (BIC) at four weeks (P<0.05), and RTQ values after four and eight weeks (P<0.05).
  
  
  CONCLUSIONS
  The study showed that an electrochemically deposited Zn-HA coating has potential for improving bone integration with an implant surface.
authors.affiliation: Department of Oral Implantology, Affiliated Stomatology Hospital, School of Medicine, Zhejiang University, Hangzhou 310006, China.
authors.forename: Shi-fang
authors.initials: SF
authors.lastname: Zhao
authors.forename: Wen-jing
authors.initials: WJ
authors.lastname: Dong
authors.forename: Qiao-hong
authors.initials: QH
authors.lastname: Jiang
authors.forename: Fu-ming
authors.initials: FM
authors.lastname: He
authors.forename: Xiao-xiang
authors.initials: XX
authors.lastname: Wang
authors.forename: Guo-li
authors.initials: GL
authors.lastname: Yang
mesh_terms: D000818:Animals; D018786:Bone Substitutes / Q000737:chemistry* / Q000627:therapeutic use; D020099:Coated Materials, Biocompatible / Q000138:chemical synthesis* / Q000494:pharmacology*; D017886:Durapatite / Q000737:chemistry / Q000494:pharmacology*; D019544:Equipment Failure Analysis; D008422:Materials Testing; D053758:Nanoparticles / Q000737:chemistry / Q000627:therapeutic use*; D016348:Osseointegration / Q000502:physiology*; D010316:Particle Size; D011474:Prosthesis Design; D011817:Rabbits; D013499:Surface Properties; D018511:Systems Integration; D015032:Zinc / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D018786:Bone Substitutes; D020099:Coated Materials, Biocompatible; D017886:Durapatite; D015032:Zinc