title: Bone bonding ability of a chemically and thermally treated low elastic modulus Ti alloy: gum metal.
abstract: The gum metal with composition Ti-36Nb-2Ta-3Zr-0.3O, is free from cytotoxic elements and exhibits a low elastic modulus as well as high mechanical strength. We have previously demonstrated that this gum metal, once subjected to a series of surface treatments--immersion in 1 M NaOH (alkali treatment) and then 100 mM CaCl2, before heating at 700 °C (sample: ACaH-GM), with an optional final hot water immersion (sample: ACaHW-GM)--has apatite-forming ability in simulated body fluid. To confirm the in vivo bioactivity of these treated alloys, failure loads between implants and bone at 4, 8, 16, and 26 weeks after implantation in rabbits' tibiae were measured for untreated gum metal (UT-GM), ACaH-GM and ACaHW-GM, as well as pure titanium plates after alkali and heat treatment (AH-Ti). The ACaH-GM and UT-GM plates showed almost no bonding, whereas ACaHW-GM and AH-Ti plates showed successful bonding by 4 weeks, and their failure loads subsequently increased with time. The histological findings showed a large amount of new bone in contact with the surface of ACaHW-GM and AH-Ti plates, suggesting that the ACaHW treatment could impart bone-bonding bioactivity to a gum metal in vivo. Thus, with this improved bioactive treatment, these advantageous gum metals become useful candidates for orthopedic and dental devices.
authors.affiliation: Department of Orthopaedic Surgery, Graduate School of Medicine, Kyoto University, 54 Kawahara-cho, Shougoin, Sakyou-ku, Kyoto, 606-8507, Japan, masashit@kuhp.kyoto-u.ac.jp.
authors.forename: Masashi
authors.initials: M
authors.lastname: Tanaka
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Takemoto
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Fujibayashi
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Kawai
authors.forename: Seiji
authors.initials: S
authors.lastname: Yamaguchi
authors.forename: Takashi
authors.initials: T
authors.lastname: Kizuki
authors.forename: Tomiharu
authors.initials: T
authors.lastname: Matsushita
authors.forename: Tadashi
authors.initials: T
authors.lastname: Kokubo
authors.forename: Takashi
authors.initials: T
authors.lastname: Nakamura
authors.forename: Shuichi
authors.initials: S
authors.lastname: Matsuda
mesh_terms: D000268:Adhesiveness; D000327:Adsorption; D000497:Alloys / Q000737:chemistry; D000818:Animals; D001860:Bone Plates; D018786:Bone Substitutes / Q000138:chemical synthesis*; D055119:Elastic Modulus; D006361:Heating; D008297:Male; D008422:Materials Testing; D016348:Osseointegration; D011817:Rabbits; D013499:Surface Properties; D013718:Tensile Strength; D013977:Tibia / Q000473:pathology / Q000503:physiopathology* / Q000601:surgery*; D013978:Tibial Fractures / Q000473:pathology / Q000503:physiopathology* / Q000601:surgery*; D014025:Titanium / Q000737:chemistry*; D016896:Treatment Outcome
chemical_list: D000497:Alloys; D018786:Bone Substitutes; D014025:Titanium