title: Surface-etching enhances titanium implant osseointegration in newly formed (rhBMP-2-induced) and native bone.
abstract: OBJECTIVE
  The influence of surface modifications on osseointegration in newly formed bone is not well established. The purpose of this study was to compare osseointegration at acid-etched versus turned implants in newly formed and native bone.
  
  
  METHODS
  Supra-alveolar peri-implant defects were created in 8 hound/Labrador mongrel dogs. Titanium implants 10 mm long (2 turned and 1 dual acid-etched) were placed 5 mm into the surgically reduced alveolar crest, creating 5-mm supra-alveolar peri-implant defects. Recombinant human bone morphogenetic protein-2 (rhBMP-2; 0.4 mg) in a collagen carrier was used to induce new bone formation. A macroporous, expanded polytetrafluoroethylene device was used to delineate new bone formation. The animals were euthanized at 8 weeks for histometric analysis of the experimental sites.
  
  
  RESULTS
  There were no significant differences in rhBMP-2-induced bone density (mean +/- SD) at acid-etched versus turned implants (20.6% +/- 5.3% vs 23.8% +/- 4.7%; P = .232). However, there was a significant difference in bone-implant contact in favor of the acid-etched implants (12.3% +/- 6.8% vs 7.9% +/- 3.1%; P = .05). Native bone density averaged 63.9% +/- 7.5% and 64.5% +/- 9.0% for acid-etched and turned implants, respectively (P = .641). Nevertheless, bone-implant contact was significantly enhanced at acid-etched versus turned implants (59.7% +/- 11.3% vs 40.7% +/-21.2%; P =.005).
  
  
  CONCLUSIONS
  Surface dual acid-etching of titanium implants has a positive effect on osseointegration in newly formed and native bone. Significant differences in bone density do not appear to influence this effect.
authors.affiliation: Laboratory for Applied Periodontal & Craniofacial Regeneration, Medical College of Georgia, School of Dentistry, Augusta, Georgia 30912, USA.
authors.forename: Mohammed
authors.initials: M
authors.lastname: Qahash
authors.forename: W Ross
authors.initials: WR
authors.lastname: Hardwick
authors.forename: Michael D
authors.initials: MD
authors.lastname: Rohrer
authors.forename: John M
authors.initials: JM
authors.lastname: Wozney
authors.forename: Ulf M E
authors.initials: UM
authors.lastname: Wikesjö
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry; D015519:Bone Density; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins / Q000627:therapeutic use; D003758:Dental Implantation, Endosseous / Q000379:methods*; D015921:Dental Implants; D004285:Dogs; D008297:Male; D008669:Metallurgy; D016348:Osseointegration / Q000502:physiology; D011994:Recombinant Proteins / Q000627:therapeutic use; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry; D016212:Transforming Growth Factor beta / Q000627:therapeutic use
chemical_list: D001672:Biocompatible Materials; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; D015921:Dental Implants; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta; C499469:recombinant human bone morphogenetic protein-2; D014025:Titanium