title: The effect of hierarchical micro/nanosurface titanium implant on osseointegration in ovariectomized sheep.
abstract: Hydrofluoric etching and anodized hierarchical micro/nanotextured surface titanium implant was placed in mandibles of ovariectomized sheep for 12 weeks, and it showed improved osseointegration by resonance frequency analysis (RFA), microcomputed tomography (micro-CT) evaluation, histomorphometry, and biomechanical test.
  
  
  BACKGROUND
  This study aimed to investigate the effects of micro/nanotextured titanium implant on osseointegration in ovariectomized (OVX) sheep.
  
  
  METHODS
  The hierarchical micro/nanotextured surface of titanium implant was fabricated by acid in 0.5% (w/v) hydrofluoric (HF) and anodized in HF acid electrolytes with a DC power of 20 V, and the machined surface implants with no treatment served as control group. The implants were placed in mandibles of OVX sheep, respectively. Twelve weeks after implantation, RFA, microcomputed tomography, histomorphometry, and biomechanical tests were applied to detect the osseointegration of the two groups.
  
  
  RESULTS
  The implant stability quotient (ISQ) values, the maximum pull-out forces, and the bone-implant contact (BIC) were 65.5 ± 6.3, 490.6 ± 72.7 N, and 58.31 ± 5.79% in the micro/nanogroup and 58.3 ± 8.9, 394.5 ± 54.5 N, and 46.85 ± 5.04% in the control group, respectively. There was no significant difference between the two groups in ISQ values (p > 0.05), but in the micro/nanogroup, the maximal pull-out force and the BIC were increased significantly (p < 0.05 or p < 0.01). Micro-CT analysis showed that the bone volume ratio and the trabecular number increased significantly (p < 0.01), and the trabecular separation decreased significantly (p < 0.05) in the micro/nanogroup.
  
  
  CONCLUSIONS
  Implant modification by HF acid etching and anodization to form a hierarchical micro/nanotextured surface could improve titanium implant osseointegration in OVX sheep 12 weeks after implantation.
authors.affiliation: Department of Oral and Maxillofacial Surgery, School of Stomatology, The Fourth Military Medical University, 145 West Changle Rd, Xi' an 710032, People's Republic of China. xiaojianrui@gmail.com
authors.forename: J
authors.initials: J
authors.lastname: Xiao
authors.forename: H
authors.initials: H
authors.lastname: Zhou
authors.forename: L
authors.initials: L
authors.lastname: Zhao
authors.forename: Y
authors.initials: Y
authors.lastname: Sun
authors.forename: S
authors.initials: S
authors.lastname: Guan
authors.forename: B
authors.initials: B
authors.lastname: Liu
authors.forename: L
authors.initials: L
authors.lastname: Kong
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D015519:Bone Density / Q000502:physiology; D045662:Dental Etching / Q000379:methods; D015921:Dental Implants; D017267:Dental Prosthesis Design; D005260:Female; D006858:Hydrofluoric Acid; D020007:Implants, Experimental; D008334:Mandible / Q000502:physiology / Q000601:surgery*; D008422:Materials Testing / Q000379:methods; D036103:Nanotechnology / Q000379:methods; D016348:Osseointegration / Q000502:physiology*; D010052:Ovariectomy; D034561:Sheep, Domestic; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry*
chemical_list: D015921:Dental Implants; D014025:Titanium; D006858:Hydrofluoric Acid