title: The role of functional parameters for topographical characterization of bone-anchored implants.
abstract: BACKGROUND
  The surface topographical characterization of bone-anchored implants has been recommended to be based on amplitude, spatial, and hybrid parameters. There are also functional parameters that have the potential to describe characteristics important for a specific application.
  
  
  OBJECTIVE
  The aim of the present study was to evaluate if parameters that have been described as functional in engineering applications are also relevant in the topographical characterization of bone-anchored implants.
  
  
  METHODS
  The surface topography of threaded titanium implants with different surface roughness (S(a), S(ds), and S(dr)) was analyzed with an optical interferometer, and five candidating functional parameters (S(bi), S(ci), S(vi), S(m), and S(c)) were calculated. Examples of the same parameters for five commercially available dental implants were also calculated. Results The highest core fluid retention index (S(ci)) was displayed by the turned implants, followed by fixtures blasted with 250- and 25-microm particles, respectively. Fixtures blasted with 75-microm Al(2)O(3) particles displayed the lowest S(ci) value. This is the inverse order of the bone biological ranking based on earlier in vivo studies with the experimental surfaces included in the present study.
  
  
  CONCLUSIONS
  A low core fluid retention index (S(ci)) seems favorable for bone-anchored implants. Therefore, it is suggested to include S(ci) to the set of topographical parameters for bone-anchored implants to possibly predict the biological outcome.
authors.affiliation: Department of Biomaterials, Göteborg University, PO Box 412, 405 30 Göteborg, Sweden. anna.arvidsson@biomaterials.gu.se
authors.forename: Anna
authors.initials: A
authors.lastname: Arvidsson
authors.forename: Bashar A
authors.initials: BA
authors.lastname: Sater
authors.forename: Ann
authors.initials: A
authors.lastname: Wennerberg
mesh_terms: D020906:Air Abrasion, Dental; D000537:Aluminum Oxide / Q000737:chemistry; D001696:Biomechanical Phenomena; D015921:Dental Implants; D003764:Dental Materials / Q000737:chemistry; D017267:Dental Prosthesis Design; D006801:Humans; D007368:Interferometry; D055095:Optics and Photonics; D010316:Particle Size; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry; D017155:Wettability
chemical_list: D015921:Dental Implants; D003764:Dental Materials; C009495:titanium dioxide; D014025:Titanium; D000537:Aluminum Oxide