title: Ultrastructure of the interface between alumina bead composite and bone.
abstract: We developed a composite (ABC) consisting of alumina bead powder as an inorganic filler and bisphenol-a-glycidyl dimethacrylate (Bis-GMA)-based resin as an organic matrix. Alumina bead powder was manufactured by fusing crushed alpha-alumina powder and quenching it. The beads took a spherical form 3 microm in average diameter. The proportion of filler in the composites was 70% w/w. The composite was implanted into rat tibiae and cured in situ. Specimens were prepared 1, 2, 4, and 8 weeks after the operation and observed by transmission electron microscopy. The results were compared with those of a bone composite made of alpha-alumina powder (alpha-ALC). In ABC-implanted tibiae, the uncured surface layer of Bis-GMA-based resin was completely filled with newly formed bonelike tissue 2 weeks after implantation. The alumina bead fillers were surrounded by and in contact with bonelike tissue. No intervening soft tissue was seen. In alpha-ALC-implanted tibiae, a gap was always observed between the alpha-ALC and the bonelike tissue. These results indicate that the ABC has osteoconductivity, although the precise mechanism is still unclear.
authors.affiliation: Department of Orthopaedic Surgery, Faculty of Medicine, Kyoto University, Kawahara-cho 54, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Okada
authors.forename: M
authors.initials: M
authors.lastname: Kobayashi
authors.forename: M
authors.initials: M
authors.lastname: Neo
authors.forename: S
authors.initials: S
authors.lastname: Shinzato
authors.forename: M
authors.initials: M
authors.lastname: Matsushita
authors.forename: T
authors.initials: T
authors.lastname: Kokubo
authors.forename: T
authors.initials: T
authors.lastname: Nakamura
mesh_terms: D000537:Aluminum Oxide / Q000737:chemistry*; D000818:Animals; D001843:Bone Cements / Q000737:chemistry*; D001842:Bone and Bones / Q000648:ultrastructure*; D003188:Composite Resins / Q000737:chemistry*; D005109:Extracellular Matrix / Q000187:drug effects / Q000648:ultrastructure; D008297:Male; D008422:Materials Testing; D008854:Microscopy, Electron; D008863:Microspheres; D051381:Rats; D017208:Rats, Wistar; D013499:Surface Properties; D013997:Time Factors
chemical_list: D001843:Bone Cements; D003188:Composite Resins; D000537:Aluminum Oxide