title: Mechanical properties and osteoconductivity of porous bioactive titanium.
abstract: Porous bioactive titanium implants (porosity of 40%) were produced by a plasma-spray method and subsequent chemical and thermal treatments of immersion in a 5M aqueous NaOH solution at 60 degrees C for 24 h, immersion in distilled water at 40 degrees C for 48 h, and heating to 600 degrees C for 1 h. Compression strength and bending strength were 280 MPa (0.2% offset yield strength 85.2 MPa) and 101 MPa, respectively. For in vivo analysis, bioactive and nontreated porous titanium cylinders were implanted into 6mm diameter holes in rabbit femoral condyles. The percentage of bone-implant contact (affinity index) of the bioactive implants (BGs) was significantly larger than for the nontreated implants (CGs) at all postimplantation times (13.5 versus 10.5, 16.7 versus 12.7, 17.7 versus 10.2, 19.1 versus 7.8 at 2, 4, 8 and 16 weeks, respectively). The percentage of bone area ingrowth showed a significant increase with the BGs, whereas with the CGs it appeared to decrease after 4 weeks (10.7 versus 9.9, 12.3 versus 13.1, 15.2 versus 9.8, 20.6 versus 8.7 at 2, 4, 8 and 16 weeks, respectively). These results suggest that porous bioactive titanium has sufficient mechanical properties and biocompatibility for clinical use under load-bearing conditions.
authors.affiliation: Department of Orthopaedic Surgery, Graduate School of Medicine, Kyoto University, Shogoin, Kawahara-cho 54, Sakyo-ku, Kyoto 606-8507, Japan.
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Takemoto
authors.forename: Shunshuke
authors.initials: S
authors.lastname: Fujibayashi
authors.forename: Mashashi
authors.initials: M
authors.lastname: Neo
authors.forename: Jun
authors.initials: J
authors.lastname: Suzuki
authors.forename: Tadashi
authors.initials: T
authors.lastname: Kokubo
authors.forename: Takashi
authors.initials: T
authors.lastname: Nakamura
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry*; D018786:Bone Substitutes / Q000737:chemistry*; D001842:Bone and Bones / Q000378:metabolism / Q000473:pathology; D020099:Coated Materials, Biocompatible / Q000737:chemistry; D017886:Durapatite / Q000737:chemistry; D005269:Femur / Q000473:pathology; D006358:Hot Temperature; D008297:Male; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D016348:Osseointegration; D019736:Prostheses and Implants; D011817:Rabbits; D013499:Surface Properties; D013696:Temperature; D013718:Tensile Strength; D013997:Time Factors; D014025:Titanium / Q000737:chemistry*
chemical_list: D001672:Biocompatible Materials; D018786:Bone Substitutes; D020099:Coated Materials, Biocompatible; D017886:Durapatite; D014025:Titanium