title: Osteoconduction of porous Ti metal enhanced by acid and heat treatments.
abstract: Bone ingrowth into porous Ti metal is important for stable fixation of Ti metal implants to surrounding bone. However, without surface treatment this is limited to only a thin region of the outer surface of the Ti metal. In the present study, a porous Ti metal with a porosity of ~60 % and interpore connections of 70-200 micrometers in diameter was investigated in terms of its chemical and heat treatments, by implanting it into rabbit femur for periods varying from 3 to 12 weeks. The porous Ti metal subjected to heat treatment at 600 °C after H2SO4/HCl mixed acid treatment showed the largest bone ingrowth in comparison with those subjected to no treatment, only acid treatment, and only heat treatment even at an early stage after implantation, and remained as such even 12 weeks after implantation. Their bone ingrowths were well interpreted in terms of apatite-forming abilities of the Ti metals in body environment. Their apatite-forming abilities did not depend upon their surface roughness nor type of crystalline phase, but upon the positive surface charge.
authors.affiliation: Department of Orthopedic Surgery, Graduate School of Medicine, Kyoto University, 54 Kawahara-cho, Shougoin Sakyou-ku, Kyoto, 606-8507, Japan. kawait@kuhp.kyoto-u.ac.jp
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Kawai
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Takemoto
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Fujibayashi
authors.forename: Haruhiko
authors.initials: H
authors.lastname: Akiyama
authors.forename: Seiji
authors.initials: S
authors.lastname: Yamaguchi
authors.forename: Deepak K
authors.initials: DK
authors.lastname: Pattanayak
authors.forename: Kenji
authors.initials: K
authors.lastname: Doi
authors.forename: Tomiharu
authors.initials: T
authors.lastname: Matsushita
authors.forename: Takashi
authors.initials: T
authors.lastname: Nakamura
authors.forename: Tadashi
authors.initials: T
authors.lastname: Kokubo
authors.forename: Shuichi
authors.initials: S
authors.lastname: Matsuda
mesh_terms: D000818:Animals; D001031:Apatites / Q000737:chemistry / Q000378:metabolism; D001861:Bone Regeneration / Q000187:drug effects* / Q000502:physiology; D019544:Equipment Failure Analysis; D005269:Femur / Q000187:drug effects / Q000502:physiology; D006358:Hot Temperature; D006851:Hydrochloric Acid / Q000494:pharmacology*; D008297:Male; D008670:Metals / Q000737:chemistry / Q000494:pharmacology; D016062:Porosity; D019736:Prostheses and Implants; D011817:Rabbits; D013499:Surface Properties / Q000187:drug effects; D014025:Titanium / Q000737:chemistry* / Q000494:pharmacology*
chemical_list: D001031:Apatites; D008670:Metals; D014025:Titanium; D006851:Hydrochloric Acid