title: Effect of hydroxyapatite and titania nanostructures on early in vivo bone response.
abstract: OBJECTIVE
  Hydroxyapatite (HA) or titania nanostructures were applied on smooth titanium implant cylinders. The aim was to investigate whether nano-HA may result in enhanced osseointegration compared to nano-titania structures.
  
  
  METHODS
  Surface topography evaluation included detailed characterization of nano-size structures present at the implant surface combined with surface roughness parameters at the micro- and nanometer level of resolution. Microstructures were removed from the surface to ensure that bone response observed was dependent only on the nanotopography and/or chemistry of the surface. Early in vivo histological analyses of the bone response (4 weeks) were investigated in a rabbit model.
  
  
  RESULTS
  In the present study, nano-titania-coated implants showed an increased coverage area and feature density, forming a homogenous layer compared to nano-HA implants. Bone contact values of the nano-titania implants showed a tendency to have a higher percentage as compared to the nano-HA implants (p = .1).
  
  
  CONCLUSIONS
  Thus, no evidence of enhanced bone formation to nano-HA-modified implants was observed compared to nano-titania-modified implants. The presence of specific nanostructures dependent on the surface modification exhibiting different size and distribution did modulate in vivo bone response.
authors.affiliation: Department of Prosthetic Dentistry, Institute of Odontology, Sahlgrenska Academy at Göteborg University, Göteborg, Sweden. meirelles@odontologi.gu.se
authors.forename: Luiz
authors.initials: L
authors.lastname: Meirelles
authors.forename: Lory
authors.initials: L
authors.lastname: Melin
authors.forename: Timo
authors.initials: T
authors.lastname: Peltola
authors.forename: Per
authors.initials: P
authors.lastname: Kjellin
authors.forename: Ilkka
authors.initials: I
authors.lastname: Kangasniemi
authors.forename: Fredrik
authors.initials: F
authors.lastname: Currie
authors.forename: Martin
authors.initials: M
authors.lastname: Andersson
authors.forename: Tomas
authors.initials: T
authors.lastname: Albrektsson
authors.forename: Ann
authors.initials: A
authors.lastname: Wennerberg
mesh_terms: D000818:Animals; D020099:Coated Materials, Biocompatible; D003758:Dental Implantation, Endosseous; D015921:Dental Implants; D017886:Durapatite; D020007:Implants, Experimental; D007368:Interferometry; D008297:Male; D018625:Microscopy, Atomic Force; D049329:Nanostructures; D016348:Osseointegration; D011817:Rabbits; D018709:Statistics, Nonparametric; D013499:Surface Properties; D013977:Tibia / Q000601:surgery; D014025:Titanium
chemical_list: D020099:Coated Materials, Biocompatible; D015921:Dental Implants; C009495:titanium dioxide; D017886:Durapatite; D014025:Titanium