Clinical Materials (Clin Mater)

Publisher: Elsevier

Journal description

Incorporated into Biomaterials

Current impact factor: 0.00

Impact Factor Rankings

Additional details

5-year impact 0.00
Cited half-life 0.00
Immediacy index 0.00
Eigenfactor 0.00
Article influence 0.00
Website Clinical Materials website
Other titles Clinical materials (Online)
ISSN 0267-6605
OCLC 60639532
Material type Periodical, Internet resource
Document type Internet Resource, Journal / Magazine / Newspaper

Publisher details

Elsevier

  • Pre-print
    • Author can archive a pre-print version
  • Post-print
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  • Conditions
    • Authors pre-print on any website, including arXiv and RePEC
    • Author's post-print on author's personal website immediately
    • Author's post-print on open access repository after an embargo period of between 12 months and 48 months
    • Permitted deposit due to Funding Body, Institutional and Governmental policy or mandate, may be required to comply with embargo periods of 12 months to 48 months
    • Author's post-print may be used to update arXiv and RepEC
    • Publisher's version/PDF cannot be used
    • Must link to publisher version with DOI
    • Author's post-print must be released with a Creative Commons Attribution Non-Commercial No Derivatives License
    • Publisher last reviewed on 03/06/2015
  • Classification
    green

Publications in this journal

  • [Show abstract] [Hide abstract]
    ABSTRACT: To reconstruct intramedullary bone stock in revision surgery of failed total hip arthroplasties, a method was developed using impacted trabecular bone grafts. In an in vitro model with femora of the goat, the initial stabilities of both cemented and non-cemented hydroxylapatite-coated stems in this graft construction were determined in a loading experiment immediately after insertion. Displacements of stems relative to bone were determined with roentgen-stereophotogrammetric analysis. The most important movements were axial rotations (cemented stems up to 2·1°, non-cemented stems up to 6·8°) and subsidence (cemented stems up to 0·5 mm, non-cemented stems up to 2·9 mm). These motions were caused predominantly by slippage and compaction of grafts. It is concluded that the cemented stems reach a better initial stability, probably by cement penetrating in the graft layer. For non-cemented stems used in combination with the grafting technique developed, additional means to guarantee initial stability are needed.
    No preview · Article · Dec 1994 · Clinical Materials
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    ABSTRACT: In the framework of a study focused on the construction of synthetic vessels of small diameter, hydroxy-functionalized polyurethane networks having elastomeric properties and a surface with potential antithrombogenic properties have been developed and characterized. The polyurethane networks were made of partly hydrolysed poly(chlorovinylether) oligomers, crosslinked by hexamethyiene diisocyanate, on which fibronectin RGD fragments have been covalently bound to its surface. The preparation steps of the poly(chloroalkylvinylether) networks and the surface anchorage of peptides is described. The biocompatibility of these polyurethanes has been evaluated under stationary cell culture conditions, before and after their surface modification by peptides. No improvment in the biocompatibility was observed in the presence of RGD.
    No preview · Article · Dec 1994 · Clinical Materials
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    ABSTRACT: This study consists of a computation of the hip joint forces of a walking patient during stance phase. A previous study was performed, which consisted of modelling the moving skeleton. The articular loading caused by muscular forces when sustaining both the external and inertial loads was then calculated. This research will provide the kinematic and dynamic boundary conditions applied to the hip joint of the patient studied. These data are essential to define the loading conditions of a patient while moving.
    No preview · Article · Dec 1994 · Clinical Materials
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    ABSTRACT: The corrosion rates of a titanium alloy, a stainless steel and a cobalt-chromium alloy have been studied over a 9-day incubation period in culture medium supplemented with foetal calf serum, with and without the presence of human osteoblasts. The release of titanium, chromium and cobalt showed a slight increase (20–40%) in the presence of osteoblasts. Cr was taken up to a greater extent (45%) by the cells. At day 9 titanium alloy was cytocompatible, whereas in contact with stainless steel and cobalt-chromium alloy osteoblast alkaline phosphatase activity was reduced, although cell growth was unaffected. This real-time testing procedure seems a good model for evaluating simultaneously in vitro the biodegradation and the biocompatibility of an orthopaedic alloy.
    No preview · Article · Dec 1994 · Clinical Materials
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    ABSTRACT: The construction of indirect composite inlays which are retained with an adhesive luting cement has been recommended as an alternative to directly placed composite resins to offset the technical and handling problems associated with these materials. It is claimed that these restorations will have acceptable, stable margins. This study investigated the marginal leakage of composite inlays cemented with either resin or glass ionomer luting materials. Twenty inlays were prepared and cemented either with Ketac-Cem or Dual cement in extracted teeth. After conditioning, the teeth were immersed in a 0·01% solution of methylene blue solution for 24 h. Following sectioning of the teeth, the site and extent of the dye penetration were assessed using an optical microscope. Results showed that less leakage occurred in the inlays cemented with glass ionomer cement when compared to the resin. With both cements, the leakage occurred at both the cement-inlay and cement-tooth interfaces. More leakage occurred at the cement-tooth interface when the resin was used.
    No preview · Article · Dec 1994 · Clinical Materials
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    ABSTRACT: A brief review is given of some of the vast array of literature on the microstructure of the mineral component of bone and its juxtapositioning with the collagen fibres. Although this survey covers a large variety of ideas, no single model emerges with universal support. However, some new experimental data from electron microscopy and X-ray diffraction are used to try to explain the way in which Nature builds mechanically efficient composite structures. This model envisages the composite to be composed of two continuous interpenetrating networks each with inherent anisotropies. In lamellar bone, individual layers contain collagen fibres which are approximately parallel to each other and to columns of the mineral hydroxyapatite. There is evidence that the detailed arrangement of these lamellae arises from the local mechanical environment, and this attractive supposition is considered.
    No preview · Article · Dec 1994 · Clinical Materials
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    ABSTRACT: Implantation of fibers of different composition (Profax, Marlex and Fortrel) in soft connective tissue demonstrated that the local cellular response was contributed by the degree of local tissue motion rather than chemical composition. Because of the difference in stiffness between synthetic fibers and connective tissue collagen, a local mechanical trauma is produced in the tissue as a result of the relative motion between fibers and tissue when the fibers are implanted at sites of flexing, i.e. across a joint.
    No preview · Article · Dec 1994 · Clinical Materials
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    ABSTRACT: Medical personnel require protection from chemical and biological hazards during clinical procedures. Methyl methacrylate monomer (MMA), used in orthopaedic and dental surgery, is capable of permeating latex gloves and can cause painful skin irritation. In this study, scanning electron microscopy has been used to demonstrate degradation of surgical latex gloves by immersion in methyl methacrylate monomer, with and without extension of the gloves. A considerable quantity of monomer was absorbed into the latex samples (7–12% of the original weight), which slowly evaporated over 10 days. A 2–3% weight loss was determined for the two types of gloves tested. Fissuring of one type of latex glove was observed after 30 min immersion in MMA.
    No preview · Article · Dec 1994 · Clinical Materials
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    ABSTRACT: This study reports results which show that, for hand-mixed glass-ionomer cements, the experience and hence, presumably, the skill of the operator is a factor in determining the values obtained for various physical properties. Four cements were studied from two manufacturers (Chelon-Fil and Chelon-Silver, supplied by ESPE GbmH, and RGI-Express and RGI-Reinforced, supplied by Rexodent Ltd) and three physical properties were considered, namely compressive strength, flexural strength and Young's modulus. In general an inexperienced operator obtained significantly lower values for all three properties for all cements than did a semi-skilled or a skilled operator. There was a smaller variation between the skilled and semi-skilled operator, which usually favoured the skilled operator. In addition, results demonstrated that the presence of metal particles improved physical properties (i.e. they were a genuine reinforcement), whereas the presence of cermet led to reduced physical properties.
    No preview · Article · Dec 1994 · Clinical Materials
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    ABSTRACT: Four calcium phosphate cements were selected to investigate whether the use of aqueous solutions of CaCl2, Na2HPO4 or NaH2PO4.2H2O instead of water had any effect on their properties. One cement was sensitive for the CaCl2 solution, two others for the phosphate solutions, and the fourth cement was insensitive to all three solutions. The setting times were reduced considerably. However, the strength values after soaking the cements in Ringer's solution for 1 day at 37°C decreased with the use of an accelerator. The use of phosphate solutions changed the pH of the cement slurry slightly during setting, whereas the CaCl2 solution had no effect on the pH.
    No preview · Article · Dec 1994 · Clinical Materials
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    ABSTRACT: Hydrogels with improved mechanical properties and acceptable levels of water absorption were developed by crosslinking poly(hydroxyethyl methacrylate), P(HEMA), with isocyanate-terminated poly(ether glycols). The crosslinking agents consisted of polyethylene glycol) (PEG) and poly(tetramethylene glycol) (PTMG) chains end-capped with hexamethylene diisocyanate (HDI). PEG of molecular weight 600 and PTMG of molecular weight 650 were used. P(HEMA) was reacted with either of the two crosslinkers alone, at concentrations of 5–30%, or with various combinations of the two crosslinkers, at total crosslinker content of 10–30%. Generally, as the level of the PEG-containing crosslinker increased, the mechanical properties of the hydrogel, both dry and wet, decreased, whereas the equilibrium water content increased. Hydrogels with a good balance between mechanical properties and water content could be obtained by adjusting the amount and composition of the crosslinking agent.
    No preview · Article · Dec 1994 · Clinical Materials
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    ABSTRACT: The principal cause of the clinical failure of bioprosthetic heart valves fabricated from glutaraldehyde-pretreated bovine pericardial valves is calcification. The present investigation describes the mineralization of glutaraldehyde-treated bovine pericardium (GBP), in an extra-circulatory environment and the possible methods of prevention via metal ions. Calcification was examined on GBP incubated in metastable solutions of calcium phosphate and the role of certain anesthetic drugs, ferric ions and magnesium ions in the media was evaluated. It seems that the addition of ethyl alcohol, pentothal and xylocaine in the calcium phosphate solutions, variably inhibited the GBP calcification. The metals like Fe3+ ions and Mg2+ ions and their combinations also substantially reduced the GBP mineralization. It is assumed that ferric ions may slow down or retard the calcification process by delaying the proper formation of hydroxyapatite while magnesium ions disrupt the growth of these crystals by replacing Ca2+. Hence, it is conceivable that a combination therapy--via local delivery of low levels of ferric ions and magnesium ions--may prevent the GBP-associated calcification. Further, a very low daily intake of alcohol appears to be beneficial to reduce the profile of calcium deposition at tissue interfaces.
    No preview · Article · Feb 1994 · Clinical Materials
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    ABSTRACT: The initial mechanical strength and strength retention in vitro and in vivo of novel absorbable and self-reinforced polyglycolide (SR-PGA) screws for the fixation of fractures and osteotomies were determined. The SR-PGA screws showed initial bending strength values comparable with those of yield strength of standard stainless steel. The SR-PGA screws lost all their bending and shear strengths in 6 weeks in vivo. The strength retention properties of SR-PGA screws are sufficient for safe fixation of relatively rapidly consolidating fractures and osteotomies of cancellous bone that are not exposed to hard mechanical stresses.
    No preview · Article · Feb 1994 · Clinical Materials
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    ABSTRACT: Fluoride content in the enamel and dentine of ancient teeth has been measured using a nuclear analysis technique. Analysed teeth were found in a vast necropolis of Sicily (Italy) which is archeologically datable between the 13th and the 8th century B.C. Measurements gave high fluoride concentrations, of the order of 10 mg per gram of hydroxyapatite, comparable with the content of fluorotic teeth of patients living nowadays in regions rich in fluorinated drinking water. Results suggest that the dental caries process was probably unknown to the tribal population living in this geographical area.
    No preview · Article · Feb 1994 · Clinical Materials
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    ABSTRACT: Five different nanoparticles, potentially useful in magnetic resonance imaging (MRI) after venous administration, were studied for their hemocompatibility. The in vitro methodology evaluated these materials by several parameters: cytotoxicity towards cells cultured in vitro, aggregation ability of platelets, hemolysis inducibility, intrinsic and extrinsic coagulation pathway activation, and complement activation. With the proposed clinical dose, regardless of the cell type used (murine cell line or human endothelial cells) no toxicity was observed. The presence of the particles in blood did not produce any considerable damage: either hemolysis or platelet aggregation or blood coagulation were recorded. However, a slight decrease in aggregation ability of platelets was noticed as well as an increase in partial thromboplastin time. Because of the quick removal of the particles from the bloodstream, these phenomena must be short-lived, thus avoiding significant adverse clinical effects.
    No preview · Article · Feb 1994 · Clinical Materials
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    ABSTRACT: Changes either within the bone cement or at the cement-bone interface are known to contribute to loosening and hence failure of many cemented joint replacements. This study examines the in vitro changes in the fracture properties of bone cement as a result of storage, at both 21 and 37 degrees C, in air, water, Ringer's solution and lipid over a period of 2 years. Specimens stored in the fluid media were found to behave in a more ductile manner than those stored in air. Samples stored at 37 degrees C behaved in a more brittle manner than those stored at 21 degrees C. Although the work of fracture values measured for the samples stored in the water-based media increased during the first 18 months, this was followed by a decrease in the subsequent 6 months.
    No preview · Article · Feb 1994 · Clinical Materials
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    ABSTRACT: The purpose of this study was to determine the potential of coralline calcium phosphate ceramics to support osteoblast growth for a proposed bone-ceramic composite for skeletal tissue repair. The goal was the development of a matrix with both osteogenic and osteoconductive properties, as compared to ceramic alone, which is solely osteoconductive. MC3T3-E1 osteoblast-like cells were seeded onto sintered and non-sintered porous coralline hydroxyapatite (HA), and onto non-porous hydroxyapatite discs. These in-vitro studies demonstrated that coralline HA supported the growth of osteoblast-like cells. Porous discs supported higher numbers of cells than non-porous discs. Sintering encouraged cell growth, with higher numbers of cells adhered to sintered porous HA discs by day seven. The results suggest that HA can provide a support for osteoblast cells as part of a matrix which may prove to be osteogenic in vivo and may, accordingly, enhance the bone repair process.
    No preview · Article · Feb 1994 · Clinical Materials
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    ABSTRACT: The aim of this study was to determine the validity with which the finite element method could model synthetic bone and thereby determine the appropriateness of such femur analogues for application in pre-clinical tests. The performance of these synthetic femora was compared with cadaveric bone when employing the same geometric and material definition protocols. A four-point bend loading configuration was selected for this analysis. Four synthetic femurs and an embalmed cadaveric bone were tested experimentally to determine the structural bending stiffness (k) for the diaphysis of these bones. A finite element (FE) model was generated and an analysis performed for each bone type to estimate the Young's modulus (E) required to obtain a model stiffness equivalent to that obtained experimentally. The estimated material elastic modulus in the FE model for the synthetic femur was found to be very similar to available data for this bone analogue. The estimated cadaveric bone modulus however was found to differ significantly from documented values for cortical bone. A theoretical analysis demonstrated the great sensitivity of the estimated modulus value to the accuracy of the geometric definition. The very low variability found in the experimental test on the synthetic bones together with their more regular geometry and the possibility of achieving greater accuracy in geometric definition was shown to enable the production of a valid FE model of this bone for an isotropic homogeneous material description. Conversely, the greater irregularity of geometry, together with the less obvious differentiation between the cortical and cancellous bone in the cadaveric specimen makes accurate geometric description of this bone very difficult. This fact, together with the uncertainty concerning the quality of the cadaveric bone and its viscoelastic response during mechanical testing, makes reproduction of its behaviour in a FE model a much more demanding task. It is suggested that this greater capability of reproducing the experimental behaviour of the synthetic bone makes them a very useful model for both experimental and numerical studies which involve in-vitro pre-clinical testing of implant design and stem-bone behaviour.
    No preview · Article · Feb 1994 · Clinical Materials