title: In vivo expression of osteogenic markers and bone mineral density at the surface of fluoride-modified titanium implants.
abstract: The aim of the present study was to investigate the biological mechanisms of the functional attachment of fluoride-modified titanium implants to cortical bone by studying the association of the pull-out test results with gene expression of osteoblast (runx2, osteocalcin, collagen-I and IGF-I), osteoclast (TRAP, H(+)-ATPase and calcitonin receptor) and inflammation (TNF-alpha, IL-6 and IL-10) markers from peri-implant bone tissue using real-time RT-PCR, following a 4- and 8-week healing period. After implant detachment, wound fluid from the implant site was collected for LDH and ALP activity analysis. A new method to study volumetric bone mineral density (vBMD) of sub-implant cortical bone was developed using micro-computed tomography. Our results show lower LDH activity and TRAP mRNA levels in fluoride implants after 4 weeks of healing, yet no differences were found either on the pull-out force or expression of bone formation marker genes. After 8 weeks of healing, both pull-out, vBMD and osteocalcin, runx2 and collage type I gene expression were higher in fluoride implants. In conclusion, fluoride-modified implants seem to modulate both inflammation and bone resorption/formation events at the bone-implant interface, suggesting that these biological effects are an intrinsic part of the clinical performance of this surface.
authors.affiliation: Department of Biomaterials, Institute for Clinical Dentistry, University of Oslo, Blindern, Oslo, Norway. marta.monjo@odont.uio.no
authors.forename: Marta
authors.initials: M
authors.lastname: Monjo
authors.forename: Sébastien F
authors.initials: SF
authors.lastname: Lamolle
authors.forename: S Petter
authors.initials: SP
authors.lastname: Lyngstadaas
authors.forename: H Jacob
authors.initials: HJ
authors.lastname: Rønold
authors.forename: Jan Eirik
authors.initials: JE
authors.lastname: Ellingsen
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism*; D015519:Bone Density; D020099:Coated Materials, Biocompatible / Q000737:chemistry / Q000378:metabolism; D005260:Female; D005459:Fluorides / Q000737:chemistry / Q000378:metabolism*; D020869:Gene Expression Profiling; D006801:Humans; D020007:Implants, Experimental; D008422:Materials Testing; D016348:Osseointegration; D010012:Osteogenesis / Q000502:physiology*; D011817:Rabbits; D013499:Surface Properties; D013718:Tensile Strength; D013977:Tibia / Q000033:anatomy & histology / Q000293:injuries / Q000378:metabolism; D014025:Titanium / Q000737:chemistry / Q000378:metabolism*
chemical_list: D015415:Biomarkers; D020099:Coated Materials, Biocompatible; D014025:Titanium; D005459:Fluorides