title: Biological response to titanium implants coated with nanocrystals calcium phosphate or type 1 collagen in a dog model.
abstract: OBJECTIVE
  The current study aimed to evaluate the osteogenic potential of electrosprayed organic and non-organic surface coatings in a gap-implant model over 4 and 12 weeks of implantation into the dog mandible.
  
  
  METHODS
  Sixteen Beagle dogs received experimental titanium implants in the mandible 3 months after removal of left premolars (P2, P3 and P4). Three types of implants were installed in each animal: non-coated implant, nano-CaP coated implant and implant with type 1 collagen coating. Both micro-CT and histomorphometry were used to evaluate peri-implant bone response after implantation periods of 4 and 12 weeks. The bone area percentage was assessed histomorphometrically in three different zones (inner: 0-300 μm; middle: 300-600 μm; and outer: 600-1000 μm) around the implant surface. Bone-bridging of the gap was also calculated for each sample.
  
  
  RESULTS
  Four weeks after implantation, nano-CaP and collagen-coated implants showed significantly higher bone volume (BV) in the inner zone compared with non-coated implants (P < 0.05 and P < 0.01). After 12 weeks, histomorphometric analysis showed comparable amounts of BV between all experimental groups. Also, no significant difference was found in the BV, as measured using micro-CT, between the implant groups. Absolute bone ingrowth measurements were highest for collagen-coated implants, but these differences were not significant.
  
  
  CONCLUSIONS
  The obtained data failed to provide a consistent favourable effect on bone formation of the collagen coating over 3 months of implantation. It is concluded that the source of the collagen as well as the limited osseous environment overshadowed a possible effect of the applied implant surface modifications. Similarly, the tested nano-apatite surface coating did not improve peri-implant bone ingrowth into a gap-implant model.
authors.affiliation: Department of Biomaterials, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands.
authors.forename: Hamdan S
authors.initials: HS
authors.lastname: Alghamdi
authors.forename: Bart A J A
authors.initials: BA
authors.lastname: van Oirschot
authors.forename: Ruggero
authors.initials: R
authors.lastname: Bosco
authors.forename: Jeroen J J P
authors.initials: JJ
authors.lastname: van den Beucken
authors.forename: Abdullah Al Farraj
authors.initials: AA
authors.lastname: Aldosari
authors.forename: Sukumaran
authors.initials: S
authors.lastname: Anil
authors.forename: John A
authors.initials: JA
authors.lastname: Jansen
mesh_terms: D000818:Animals; D002130:Calcium Phosphates / Q000494:pharmacology*; D020099:Coated Materials, Biocompatible / Q000494:pharmacology*; D024042:Collagen Type I / Q000494:pharmacology*; D003758:Dental Implantation, Endosseous; D015921:Dental Implants; D004285:Dogs; D020007:Implants, Experimental; D008334:Mandible / Q000601:surgery; D053758:Nanoparticles; D016348:Osseointegration / Q000187:drug effects*; D013499:Surface Properties; D014025:Titanium / Q000494:pharmacology*; D055114:X-Ray Microtomography
chemical_list: D002130:Calcium Phosphates; D020099:Coated Materials, Biocompatible; D024042:Collagen Type I; D015921:Dental Implants; D014025:Titanium