title: Surface characteristics of electrochemically oxidized implants and acid-etched implants: surface chemistry, morphology, pore configurations, oxide thickness, crystal structure, and roughness.
abstract: OBJECTIVE
  This study was undertaken to investigate surface properties of surface-modified titanium implants in terms of surface chemistry, morphology, pore characteristics, oxide thickness, crystal structure, and roughness.
  
  
  METHODS
  An oxidized, custom-made Mg implant, an oxidized commercially available implant (TiUnite), and a dual acid-etched surface (Osseotite) were investigated. Surface characteristics were evaluated with various surface analytic techniques.
  
  
  RESULTS
  Surface chemistry showed similar fingerprints of titanium oxide and carbon contaminant in common for all implants but also revealed essential differences of the elements such as about 9 at% Mg for the Mg implant, about 11 at% P for the TiUnite implant and about 12 at% Na for the Osseotite implant. Surface morphology of the Mg and TiUnite implants demonstrated a duplex oxide structure, ie, an inner barrier layer without pores and an outer porous layer with numerous pores, whereas the Osseotite implant revealed a crystallographically etched appearance with pits. The diameter and depth of pores/pits was < or = 2 microm and < or = 1.5 microm in the Mg implant, < or = 4 microm and < or = 10 microm in the TiUnite implant, and < or = 2 microm and < or = 1 microm in the Osseotite implant, respectively. Oxide layer revealed homogeneous thickness, about 3.4 microm of all threads in the Mg implants. On the contrary, TiUnite showed heterogeneous oxide thickness, about 1 to 11 microm, which gradually increased with thread numbers. Crystal structure showed a mixture of anatase and rutile phase for the Mg implants. With respect to roughness, Sa showed 0.69 microm in the Mg implant, 1.35 microm in the TiUnite implant, and 0.72 microm in the Osseotite implant.
  
  
  CONCLUSIONS
  Well-defined surface characterization may provide a scientific basis for a better understanding of the effects of the implant surface on the biological response. The surface-engineered implants resulted in various surface characteristics, as a result of different manufacturing techniques.
authors.affiliation: Department of Biomaterials/Handicap Research, Institute for Clinical Sciences, Sahlgrenska Academy at Göteborg University, Göteborg, Sweden. young-taeg.sul@biomaterials.gu.se
authors.forename: Young-Taeg
authors.initials: YT
authors.lastname: Sul
authors.forename: Eungsun
authors.initials: E
authors.lastname: Byon
authors.forename: Ann
authors.initials: A
authors.lastname: Wennerberg
mesh_terms: D000134:Acid Etching, Dental; D020099:Coated Materials, Biocompatible; D003460:Crystallization; D003722:Dental Alloys; D015921:Dental Implants; D017267:Dental Prosthesis Design; D004577:Electron Probe Microanalysis; D008277:Magnesium Oxide; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D016062:Porosity; D013499:Surface Properties; D014025:Titanium
chemical_list: D020099:Coated Materials, Biocompatible; D003722:Dental Alloys; D015921:Dental Implants; C009495:titanium dioxide; D008277:Magnesium Oxide; D014025:Titanium