title: Effects of different hierarchical hybrid micro/nanostructure surfaces on implant osseointegration.
abstract: BACKGROUND
  Hierarchical hybrid micro/nanostructure implant surfaces are considered to better mimic the hierarchical structure of bone and the nanostructures substantively influence osseointegration through managing cell behaviors.
  
  
  OBJECTIVE
  To enhance implant osseointegration for further clinical application, we evaluated the material properties and osseointegration effects of hierarchical surfaces with different nano-morphologies, using a rat model.
  
  
  METHODS
  Two representative surface fabrication methods, hydrofluoric (HF) acid etching combined with anodization (HF + AN) or magnetron sputtering (HF + MS), were selected. Sample material properties were evaluated by scanning electron microscopy, atomic force microscopy, X-ray diffraction, X-ray photoemission spectroscopy, and epoxy resin docking tensile test. Implants with different surfaces were inserted into the distal femurs of rats. After 12 weeks, osseointegration was examined by microcomputed tomography (micro-CT), histological, and biomechanical tests.
  
  
  RESULTS
  Tensile testing demonstrated high bonding strength at coating/implant in the HF + MS group. Micro-CT revealed increased bone volume/total volume and significantly reduced trabecular separation in HF + MS versus other groups. Histological analysis showed significantly higher HF + MS bone-to-implant contact (74.78 ± 4.40%) versus HF + AN (65.11 ± 5.10%) and machined samples (56.03 ± 3.23%). The maximal HF + MS pull-out force increased by 33.7% versus HF + AN.
  
  
  CONCLUSIONS
  These results indicated that HF + MS surfaces exhibited superior material property in terms of bonding strength and favorable implant osseointegration compared to other groups.
authors.affiliation: State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi Key Laboratory of Oral Diseases, Department of Oral and Maxillofacial Surgery, School of Stomatology, The Fourth Military Medical University, 145 West Changle Road, Xi'an, Shaanxi, 710032, China.|Department of Oral and Maxillofacial Surgery, The Second Hospital of Hebei Medical University, Shijiazhuang, Hebei, 050000, China.
authors.forename: Bingkun
authors.initials: B
authors.lastname: Cheng
authors.affiliation: State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi Key Laboratory of Oral Diseases, Department of Oral and Maxillofacial Surgery, School of Stomatology, The Fourth Military Medical University, 145 West Changle Road, Xi'an, Shaanxi, 710032, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Niu
authors.affiliation: Orthopedic Research Laboratory, Boston Children's Hospital, 300 Longwood AVE, Boston, MA, 02115, USA.
authors.forename: Yajun
authors.initials: Y
authors.lastname: Cui
authors.affiliation: State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi Key Laboratory of Oral Diseases, Department of Oral and Maxillofacial Surgery, School of Stomatology, The Fourth Military Medical University, 145 West Changle Road, Xi'an, Shaanxi, 710032, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Jiang
authors.affiliation: Department of Oral and Maxillofacial Surgery, The Second Hospital of Hebei Medical University, Shijiazhuang, Hebei, 050000, China.
authors.forename: Yunzhuan
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi Key Laboratory of Oral Diseases, Department of Oral and Maxillofacial Surgery, School of Stomatology, The Fourth Military Medical University, 145 West Changle Road, Xi'an, Shaanxi, 710032, China.
authors.forename: Liang
authors.initials: L
authors.lastname: Kong
mesh_terms: D000134:Acid Etching, Dental; D000818:Animals; D001840:Dental Bonding; D003758:Dental Implantation, Endosseous; D006858:Hydrofluoric Acid; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D013499:Surface Properties; D013718:Tensile Strength
chemical_list: D006858:Hydrofluoric Acid
keywords: implant; micro/nanorough; nanonodules; nanotubes; osseointegration