title: Optimisation of the hydrogen peroxide pre-treatment of titanium: surface characterisation and protein adsorption.
abstract: BACKGROUND
  Researchers have attempted to enhance titanium osseointegration by modifying its surface properties, including via H(2)O(2) pre-treatment, with reported treatment regimes varying from minutes/hours, to weeks.
  
  
  OBJECTIVE
  This study examined the effects of various H(2)O(2) treatments on titanium surface topography/roughness, chemical composition/oxide thickness, hydrophilicity and plasma protein adsorption.
  
  
  METHODS
  Titanium discs were treated with 30% H(2)O(2) for 0-24 h or 1-4 weeks and subjected to atomic force microscopy (AFM), scanning electron microscopy (SEM), profilometry, X-ray photon spectroscopy and contact angle analysis. For protein adsorption, whole plasma and FITC-conjugated serum albumin were added to 0-24 h and 1-4 week H(2)O(2)-treated discs and examined by SEM and fluorescence microscopy, respectively.
  
  
  RESULTS
  AFM, SEM and profilometry demonstrated that 1-6 h H(2)O(2)-treated discs exhibited subtle alterations in surface topography/roughness at the nanometre scale, although 24 h and 1-4 week H(2)O(2)-treated discs exhibited much greater increases in surface roughness, in the micrometre range. Maximal increases in surface oxide thickness and chemical modification were identified between 1 h-4 weeks and 3 h-4 weeks, respectively, although no increases in oxygen/titanium (O1s : Ti2p) molar ratio or in hydrophilicity were evident. Plasma and serum albumin adsorption increased on 1-24 h H(2)O(2)-treated discs, with further increases on 1-4 week H(2)O(2)-treated discs.
  
  
  CONCLUSIONS
  Based upon the present data and previous findings, this study supports the concept that surface topography/roughness and oxide composition/thickness, are more significantly modified by H(2)O(2) treatment and more influential to protein adsorption than hydrophilicity. Additionally, it can be hypothesized that the 24 h H(2)O(2) treatment of titanium surfaces, which induced micrometre scale changes in roughness and protein adsorption, to those associated with enhanced osteoblast attachment/behaviour, mineralisation and subsequent implant osseointegration, would be most beneficial.
authors.affiliation: Wound Biology Group, Department of Oral Surgery, Medicine, & Pathology, School of Dentistry, Cardiff University, Cardiff, UK.
authors.forename: M E
authors.initials: ME
authors.lastname: Nagassa
authors.forename: A E
authors.initials: AE
authors.lastname: Daw
authors.forename: W G
authors.initials: WG
authors.lastname: Rowe
authors.forename: A
authors.initials: A
authors.lastname: Carley
authors.forename: D W
authors.initials: DW
authors.lastname: Thomas
authors.forename: R
authors.initials: R
authors.lastname: Moseley
mesh_terms: D000327:Adsorption / Q000187:drug effects; D000704:Analysis of Variance; D001672:Biocompatible Materials / Q000737:chemistry* / Q000493:pharmacokinetics; D001798:Blood Proteins / Q000378:metabolism; D015921:Dental Implants; D006861:Hydrogen Peroxide / Q000737:chemistry* / Q000494:pharmacology; D018625:Microscopy, Atomic Force; D016348:Osseointegration; D016877:Oxidants / Q000737:chemistry* / Q000494:pharmacology; D018709:Statistics, Nonparametric; D013499:Surface Properties / Q000187:drug effects; D014025:Titanium / Q000737:chemistry* / Q000493:pharmacokinetics
chemical_list: D001672:Biocompatible Materials; D001798:Blood Proteins; D015921:Dental Implants; D016877:Oxidants; D006861:Hydrogen Peroxide; D014025:Titanium