title: Effects of implant geometry, surface properties, and TGF-beta1 on peri-implant bone response: an experimental study in goats.
abstract: OBJECTIVE
  Despite the high success rates in implantology, the desire to use oral implants in more challenging clinical situations drives the need for continuing refinements in implant design and surface properties. In the present study, the effect of implant geometry on implant bone response was evaluated using two geometrically different implant types, i.e. screw type (St) and push-in type(Pi). Furthermore, the potential beneficial effect of an electrosprayed calcium phosphate (CaP) coating, either or not enriched with the osteoinductive growth factor TGF-beta1, on the osteogenic response was examined.
  
  
  METHODS
  A total of 54 implants, divided into six groups (n=9), were inserted into the femoral condyles of nine goats. After an implantation period of 12 weeks, retrieved specimens were evaluated histologically and histomorphometrically. Measurements were statistically evaluated using SPSS 14.0 and analyzed using a linear regression model.
  
  
  RESULTS
  With respect to implant design, St-implants showed an overall superior biological healing response compared with Pi-implants. Considering surface properties, the deposition of an electrosprayed CaP (2-3 microm) coating onto implants significantly increased the amount of bone-implant contact for both implant types. Additional enrichment of the CaP coating with the osteoinductive growth factor TGF-beta1 did not significantly affect peri-implant bone response.
  
  
  CONCLUSIONS
  The results of this study indicate that a substantial improvement of the osteogenic response to titanium implants can be achieved by the deposition of an electrosprayed CaP coating. The enrichment of the coating with 1 microg TGF-beta1 has only a marginal effect.
authors.affiliation: Department of Periodontology & Biomaterials, Radboud University Nijmegen Medical Center, Nijmegen, The Netherlands.
authors.forename: C
authors.initials: C
authors.lastname: Schouten
authors.forename: G J
authors.initials: GJ
authors.lastname: Meijer
authors.forename: J J J P
authors.initials: JJ
authors.lastname: van den Beucken
authors.forename: P H M
authors.initials: PH
authors.lastname: Spauwen
authors.forename: J A
authors.initials: JA
authors.lastname: Jansen
mesh_terms: D000818:Animals; D001861:Bone Regeneration / Q000187:drug effects / Q000502:physiology; D002130:Calcium Phosphates / Q000008:administration & dosage; D020099:Coated Materials, Biocompatible / Q000008:administration & dosage*; D003758:Dental Implantation, Endosseous / Q000295:instrumentation / Q000379:methods*; D015921:Dental Implants; D017267:Dental Prosthesis Design; D005260:Female; D005269:Femur / Q000187:drug effects / Q000601:surgery; D006041:Goats; D008856:Microscopy, Fluorescence; D016348:Osseointegration / Q000187:drug effects / Q000502:physiology*; D013499:Surface Properties; D053773:Transforming Growth Factor beta1 / Q000008:administration & dosage* / Q000502:physiology; D014945:Wound Healing / Q000187:drug effects / Q000502:physiology
chemical_list: D002130:Calcium Phosphates; D020099:Coated Materials, Biocompatible; D015921:Dental Implants; D053773:Transforming Growth Factor beta1; C020243:calcium phosphate