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  • 1
    Publication Date: 1987-04-01
    Print ISSN: 0302-766X
    Electronic ISSN: 1432-0878
    Topics: Biology , Medicine
    Published by Springer
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  • 2
    Publication Date: 1972-01-01
    Print ISSN: 0302-766X
    Electronic ISSN: 1432-0878
    Topics: Biology , Medicine
    Published by Springer
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  • 3
    Publication Date: 1985-01-01
    Print ISSN: 0018-2222
    Electronic ISSN: 1432-119X
    Topics: Biology , Medicine
    Published by Springer
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  • 4
    Publication Date: 1984-01-01
    Print ISSN: 0018-2222
    Electronic ISSN: 1432-119X
    Topics: Biology , Medicine
    Published by Springer
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Journal of materials science 4 (1993), S. 240-250 
    ISSN: 1573-4838
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Technology
    Notes: The tissue response to screw-shaped implants of commercially pure titanium was studied by light microscopy 3–180 days after insertion in the rabbit tibia. The implant site in the tibial metaphysis consisted mainly of cortical bone. Three days after implantation, osteoblasts, producing osteoid, were observed at the endosteal surface and elongated mesenchymal cells were present in the injury area. Some macrophages but rather few other inflammatory cells were identified. Multinuclear giant cells were in direct contact with the implant and formed an almost continuous layer along the surface from the 7th day. The number of giant cells decreased with time and with increased bone-titanium contact. Bone formation was never seen direct on the implant surface but was first observed at day 7 as a woven trabecular bone formed at the endosteal surface and extending towards the implant and as a solitary formation of woven bone close to the implant. The solitary bone matrix served as a base for surface osteoblasts which produced osteoid in a lamellar arrangement. With time the two types of newly formed bone fused and more bone filled the threads and became remodelled by bone remodelling units. Light microscopic morphometry in ground sections demonstrated that the bone/titanium contact and bone area in the threads increased with time up to 6 months after implantation
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Journal of materials science 3 (1992), S. 262-271 
    ISSN: 1573-4838
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Technology
    Notes: Abstract The interface zone between cortical bone and threaded non-alloyed titanium implants inserted in the rabbit tibia for 12 months was examined by light and electron microscopy. The implants were removeden bloc with the perfusion-fixed surrounding bone and the undecalcified specimens were, after osmification, dehydrated and embedded in plastic resin (LR White). In ground sections (about 10 µm thick) cortical bone appeared to be in direct contact with the implant surface and the implants were thus “osseointegrated”. Sections for light microscopy (1 µm thick) and electron microscopy (40 nm to 0.5 µm) were prepared by using an electropolishing technique by which the bulk part of the metal was electrochemically removed and a fracture technique by which the implant was separated from the embedded tissue before sectioning. In the electropolished specimens an unmineralized zone, 2–10 µm wide, was observed at the interface. The interface zone contained osteoid-like tissue (densely packed collagen fibrils, osteocyte canaliculi) but in general no deposits of calcium mineral. This feature of the interface could not be observed in specimens prepared by the fracture technique, indicating that the electropolishing technique had induced serious artefacts, including decalcification of the interface bone. In sections prepared by the fracture technique, mineralized bone was present very close to the implant surface. No gradient of mineral was observed. A thin layer of amorphous material (100–200 nm wide) was present peripheral to the mineralized bone. An electron dense line about 100 nm wide was formed at the border between the mineralized bone and the amorphous layer. The dense layer had the same characteristics as the lamina limitans observed around osteocyte lacunae and canaliculi or the zone between areas of bone with different degree of mineralization. Our observations suggest that mineralized bone reached close to the surface of titanium implants inserted in the rabbit tibia for 12 months but that a direct contact is not established.
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Journal of materials science 6 (1995), S. 435-444 
    ISSN: 1573-4838
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Technology
    Notes: The tissue response in rats to implants made of machined and cast titanium was evaluated after 1 and 12 weeks. The implants consisted of a circular plate portion, located in the abdominal wall, and a cylindrical rod portion protruding into the peritoneal cavity. The chemical and topographical surface properties of the two types of implants differed considerably. The implants with surrounding tissue were processed en bloc for light and electron microscopy. The bulk metal was removed by an electrochemical procedure which permitted the sectioning and evaluation of the intact implant-tissue interface. The general distribution of macrophages and fibroblasts was the same around the plate portion of both types of implants. Macrophages constituted the predominating cell type with the highest concentration in the innermost cell zone closest to the implant. The number of macrophages per section area was significantly higher around machined implants. Multinuclear giant cells, always located at the implant surface, were more frequent around cast implants. The majority of the intraperitoneal rod portions were partially (1 week) or completely (12 weeks) covered by tissue; partial or complete overgrowth of tissue was rare for machined rod portions. Imaging electron energy loss spectroscopy demonstrated the presence of titanium in macrophages in the peripheral part of the tissue capsule around cast, but not machined implants. We conclude that the tissue responses to the two types of titanium implants differed considerably in the two biological environments (soft tissue in abdominal wall; peritoneal cavity) examined and that the response in one environment does not predict the response in the other. We also believe that improvements have to be made in the casting procedure in order to reduce surface roughness and contamination before cast implants can be used in clinical applications.
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  • 8
    ISSN: 1573-4838
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Technology
    Notes: Abstract The role of surface properties (chemical and structural) for the interaction between biomaterials and tissue is not yet understood. In the present study, implants made of titanium, zirconium (transition metals with surface oxides) and gold (metallic surface) were inserted into the rabbit tibia. Light microscopic (LM) morphometry showed that after 1 and 6 mo the gold implants had less amount of bone within the threads and a lower degree of bone-implant contact than the titanium and zirconium implants, which did not differ from each other. These quantitative differences were supported by LM and ultrastructural observations of the interface. The ultrastructural observations in addition demonstrated that the layer of non-collagenous amorphous material located between the implant and the calcified bone was appreciably thicker around zirconium than around titanium implants. The factors potentially responsible for the observed morphological differences in the bone around the different material surfaces are discussed.
    Type of Medium: Electronic Resource
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  • 9
    ISSN: 1573-4838
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Technology
    Notes: Abstract The bone formation around titanium implants with varied surface properties was investigated after 1 year in rabbits. Machined and electropolished samples with and without thick, anodically formed surface oxides were prepared, surface characterized and inserted in the cortical bone of rabbits. Scanning electron microscopy, scanning Auger electron spectroscopy and atomic force microscopy revealed marked differences in oxide thickness, surface topography and roughness, but no significant differences in surface chemical composition between the different groups of implants. Light microscopic morphology and morphometry showed that all implants were in contact with bone and had a large proportion of bone within the threads. There were no significant differences between the differently prepared implant groups. Our study shows that a high degree of bone contact and bone formation is achieved after 1 year with titanium implants which are modified with respect to oxide thickness and surface topography. There is no indication that a reduction of surface roughness, which in the initial phase decreases the rate of bone formation, had any influence on the amount of bone after 1 year in rabbit cortical bone.
    Type of Medium: Electronic Resource
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  • 10
    ISSN: 1573-4838
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Technology
    Notes: Abstract Commercially pure (c.p.) titanium and Ti-6Al-4V implants were inserted in the abdominal wall of rats. The surrounding fluid space, inflammatory cells and fibrous capsule were evaluated after 1, 6 and 12 weeks. Light-microscopic morphometry demonstrated a fluid space around both implant materials which gradually decreased with time. Macrophages were preferentially distributed close to the implant surface in the innermost zone (0–25 µm from the surface). In contrast, fibroblasts and endothelial cells were located mainly in the outer three zones (25–100 µm from the surface). At all time periods studied and around both materials, lymphocytes were detected throughout the surrounding tissue. The outer border of the fibrous capsule, which consisted of macrophages, fibroblasts, endothelial cells and collagen, was difficult to define, in particular during the early phase of healing. At later time stages, 6 and 12 weeks, no difference in width (60–90 µm) was observed between the two materials. No major quantitative differences with respect to the number of different cells, fluid space width and fibrous capsule thickness were noted between the two materials studied. The observed mild inflammatory reaction and the absence of statistically significant differences between c.p. titanium and Ti-6Al-4V in soft tissue indicate that both materials could be suitable for use in soft tissues. In the context of previous comparative studies it may be concluded that the animal species as well as the different implantation locals play an important role in the determination of biocompatibility.
    Type of Medium: Electronic Resource
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