title: Porous ceramic titanium dioxide scaffolds promote bone formation in rabbit peri-implant cortical defect model.
abstract: Titanium oxide (TiO₂) scaffolds have previously been reported to exhibit very low mechanical strength. However, we have been able to produce a scaffold that features a high interconnectivity, a porosity of 91% and a compressive strength above 1.2 MPa. This study analyzed the in vivo performance of the porous TiO₂ scaffolds in a peri-implant cortical defect model in the rabbit. After 8 weeks of healing, morphological microcomputed tomography analyses of the defects treated with the TiO₂ scaffolds had significantly higher bone volume, bone surface and bone surface-to-volume ratio when compared to sham, both in the cortical and bone marrow compartment. No adverse effects, i.e. tissue necrosis or inflammation as measured by lactate dehydrogenase activity and real-time reverse transcription polymerase chain reaction analysis, were observed. Moreover, the scaffold did not hinder bone growth onto the adjacent cortical titanium implant. Histology clearly demonstrated new bone formation in the cortical sections of the defects and the presence of newly formed bone in close proximity to the scaffold surface and the surface of the adjacent Ti implant. Bone-to-material contact between the newly formed bone and the scaffold was observed in the histological sections. Islets of new bone were also present in the marrow compartment albeit in small amounts. In conclusion, the present investigation demonstrates that TiO₂ scaffolds osseointegrate well and are a suitable scaffold for peri-implant bone healing and growth.
authors.affiliation: Department of Biomaterials, University of Oslo, Oslo, Norway. h.j.haugen@odont.uio.no
authors.forename: Håvard Jostein
authors.initials: HJ
authors.lastname: Haugen
authors.forename: Marta
authors.initials: M
authors.lastname: Monjo
authors.forename: Marina
authors.initials: M
authors.lastname: Rubert
authors.forename: Anders
authors.initials: A
authors.lastname: Verket
authors.forename: Ståle Petter
authors.initials: SP
authors.lastname: Lyngstadaas
authors.forename: Jan Eirik
authors.initials: JE
authors.lastname: Ellingsen
authors.forename: Hans Jacob
authors.initials: HJ
authors.lastname: Rønold
authors.forename: Johan Caspar
authors.initials: JC
authors.lastname: Wohlfahrt
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000494:pharmacology; D015519:Bone Density / Q000187:drug effects / Q000235:genetics; D001842:Bone and Bones / Q000000981:diagnostic imaging / Q000187:drug effects* / Q000473:pathology*; D016923:Cell Death / Q000187:drug effects; D002516:Ceramics / Q000494:pharmacology*; D004195:Disease Models, Animal; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects; D020007:Implants, Experimental; D007249:Inflammation / Q000235:genetics / Q000473:pathology; D008422:Materials Testing; D010012:Osteogenesis / Q000187:drug effects* / Q000235:genetics; D016062:Porosity; D011817:Rabbits; D054457:Tissue Scaffolds / Q000737:chemistry*; D014025:Titanium / Q000494:pharmacology*; D014945:Wound Healing / Q000187:drug effects; D055114:X-Ray Microtomography
chemical_list: D001672:Biocompatible Materials; C009495:titanium dioxide; D014025:Titanium