title: The In Vivo Bone Response of Ultraviolet-Irradiated Titanium Implants Modified with Spontaneously Formed Nanostructures: An Experimental Study in Rabbits.
abstract: OBJECTIVE
  Acid etching in conjunction with storage in an aqueous solution can induce nanostructures forming spontaneously on titanium surfaces, but an inevitable biologic degradation is suspected to accompany the evolution of nanostructures. The aim of this study was to investigate whether ultraviolet (UV) irradiation is effective to solve this problem and further enhance the bioactivity.
  
  
  METHODS
  Surface characteristics of five groups of titanium implants (SLAnew, SLAold, modSLA, UV-SLA, and UV-modSLA) and their in vivo bone response were analyzed in this study. The surface characteristics were evaluated with contact angle measurements, scanning electron microscopy, and x-ray photon spectroscopy. A total of 160 implants (32 for each group) were inserted into the tibial metaphyses and femoral condyles of 40 rabbits. After 3 and 6 weeks, the rabbits were euthanized for removal torque tests and histomorphometric analysis.
  
  
  RESULTS
  Spontaneously formed nanostructures were observed on water-stored surfaces with a size of approximately 15 nm in diameter, and an inevitable contamination of hydrocarbons accompanied the evolution of nanostructures. UV irradiation effectively eliminated hydrocarbon contamination that accompanied nanostructure evolution. UV-modSLA implants showed the highest removal torque value, and UV-irradiated implants exhibited higher bone-to-implant contact and bone area.
  
  
  CONCLUSIONS
  UV irradiation can effectively eliminate the hydrocarbon contamination accompanying the evolution of nanostructures and further enhance the osseointegration. Nanostructures and UV treatment have combined effects in enhancing the interfacial strength between titanium and bone, while UV photofunctionalization has much more overwhelming effects on histologic and histomorphometric performance.
authors.forename: Jianwei
authors.initials: J
authors.lastname: Shen
authors.forename: Jianhu
authors.initials: J
authors.lastname: Liu
authors.forename: Xiaoyi
authors.initials: X
authors.lastname: Chen
authors.forename: Xiaoxiang
authors.initials: X
authors.lastname: Wang
authors.forename: Fuming
authors.initials: F
authors.lastname: He
authors.forename: Huiming
authors.initials: H
authors.lastname: Wang
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000528:radiation effects*; D000069343:Bone-Implant Interface / Q000502:physiology; D003758:Dental Implantation, Endosseous / Q000379:methods; D015921:Dental Implants; D017267:Dental Prosthesis Design; D004195:Disease Models, Animal; D005269:Femur / Q000601:surgery; D006838:Hydrocarbons / Q000528:radiation effects; D020007:Implants, Experimental; D008855:Microscopy, Electron, Scanning; D049329:Nanostructures / Q000737:chemistry / Q000528:radiation effects*; D016348:Osseointegration / Q000502:physiology / Q000528:radiation effects; D011817:Rabbits; D013499:Surface Properties / Q000528:radiation effects*; D014025:Titanium / Q000528:radiation effects*; D019415:Torque; D014466:Ultraviolet Rays
chemical_list: D001672:Biocompatible Materials; D015921:Dental Implants; D006838:Hydrocarbons; D014025:Titanium