The Experts below are selected from a list of 14472 Experts worldwide ranked by ideXlab platform

Takashi Nakamura - One of the best experts on this subject based on the ideXlab platform.

  • mechanical properties of glass ceramic a w polyethylene composites effect of Filler Content and particle size
    Biomaterials, 2004
    Co-Authors: J A Juhasz, Serena M Best, R A Brooks, Masakazu Kawashita, Noboru Miyata, Tadashi Kokubo, Takashi Nakamura, W Bonfield
    Abstract:

    Abstract Composites which comprise a bioactive Filler and ductile polymer matrix are desirable as implant materials since both their biological and mechanical properties can be tailored for a given application. In the present study three-point bending was used to characterise biomedical materials composed of glass-ceramic apatite–wollastonite (A–W) particulate reinforced polyethylene (PE) (denoted as AWPEX). The effects of Filler volume fraction, varied from 10 to 50 vol%, and average particle size, 4.4 and 6.7 μm, on the bending strength, yield strength, mode of fracture, Young's modulus and strain to failure were investigated. HAPEX™, a commercially used composite of hydroxyapatite and polyethylene, with a 40 vol% Filler Content, was used for comparison. Increasing the Filler Content caused an increase in Young's modulus, yield strength and bending strength, and a decreased strain to failure. When Filler particle size was increased, the Young's modulus, yield and bending strengths were found to be slightly reduced. A transition in fracture behaviour from ductile to brittle behaviour was observed in samples containing between 30 and 40 vol% Filler.

  • Mechanical properties of glass-ceramic A–W-polyethylene composites: effect of Filler Content and particle size
    Biomaterials, 2004
    Co-Authors: J A Juhasz, Serena M Best, R A Brooks, Masakazu Kawashita, Noboru Miyata, Tadashi Kokubo, Takashi Nakamura, W Bonfield
    Abstract:

    Abstract Composites which comprise a bioactive Filler and ductile polymer matrix are desirable as implant materials since both their biological and mechanical properties can be tailored for a given application. In the present study three-point bending was used to characterise biomedical materials composed of glass-ceramic apatite–wollastonite (A–W) particulate reinforced polyethylene (PE) (denoted as AWPEX). The effects of Filler volume fraction, varied from 10 to 50 vol%, and average particle size, 4.4 and 6.7 μm, on the bending strength, yield strength, mode of fracture, Young's modulus and strain to failure were investigated. HAPEX™, a commercially used composite of hydroxyapatite and polyethylene, with a 40 vol% Filler Content, was used for comparison. Increasing the Filler Content caused an increase in Young's modulus, yield strength and bending strength, and a decreased strain to failure. When Filler particle size was increased, the Young's modulus, yield and bending strengths were found to be slightly reduced. A transition in fracture behaviour from ductile to brittle behaviour was observed in samples containing between 30 and 40 vol% Filler.

  • apatite forming ability of glass ceramic apatite wollastonite polyethylene composites effect of Filler Content
    Journal of Materials Science: Materials in Medicine, 2003
    Co-Authors: J A Juhasz, Serena M Best, Masakazu Kawashita, Noboru Miyata, Tadashi Kokubo, W Bonfield, Takashi Nakamura
    Abstract:

    The bioactivity of a range of glass-ceramic apatite–wollastonite (A–W) – polyethylene composites (AWPEXs) with glass-ceramic A–W volume percentages ranging from 10 to 50, has been investigated in an acellular simulated body fluid (SBF) with ion concentrations similar to those of human blood plasma. The formation of a biologically active apatite layer on the composite surface after immersion in SBF was demonstrated by thin-film X-ray diffraction (TF-XRD) and field-emission scanning electron microscopy (FE-SEM). An apatite layer was formed on all the composites, with the rate of formation increasing with an increase in glass-ceramic A–W percentage. For composites with glass-ceramic A–W Filler Contents ≥30 vol %, the apatite layer was formed within 12 h of immersion, which is a comparable time for apatite formation on monolithic glass-ceramic A–W. Inductively coupled plasma atomic emission spectroscopy (ICP-AES) demonstrated that the apatite formation on AWPEX samples with 50 vol % Filler Content occurred in a manner similar to that seen on pure glass-ceramic A–W, in that the calcium, silicon, and magnesium ion concentrations increased and, conversely, a decrease was observed in the phosphate ion concentration. These results indicate that a suitable in vitro response was achieved on a composite incorporating particulate glass-ceramic A–W with a particularly favorable response being observed on the AWPEX sample with 50 vol % Filler Content.

  • Apatite-forming ability of glass-ceramic apatite–wollastonite – polyethylene composites: effect of Filler Content
    Journal of Materials Science: Materials in Medicine, 2003
    Co-Authors: J A Juhasz, Serena M Best, Masakazu Kawashita, Noboru Miyata, Tadashi Kokubo, W Bonfield, Takashi Nakamura
    Abstract:

    The bioactivity of a range of glass-ceramic apatite–wollastonite (A–W) – polyethylene composites (AWPEXs) with glass-ceramic A–W volume percentages ranging from 10 to 50, has been investigated in an acellular simulated body fluid (SBF) with ion concentrations similar to those of human blood plasma. The formation of a biologically active apatite layer on the composite surface after immersion in SBF was demonstrated by thin-film X-ray diffraction (TF-XRD) and field-emission scanning electron microscopy (FE-SEM). An apatite layer was formed on all the composites, with the rate of formation increasing with an increase in glass-ceramic A–W percentage. For composites with glass-ceramic A–W Filler Contents ≥30 vol %, the apatite layer was formed within 12 h of immersion, which is a comparable time for apatite formation on monolithic glass-ceramic A–W. Inductively coupled plasma atomic emission spectroscopy (ICP-AES) demonstrated that the apatite formation on AWPEX samples with 50 vol % Filler Content occurred in a manner similar to that seen on pure glass-ceramic A–W, in that the calcium, silicon, and magnesium ion concentrations increased and, conversely, a decrease was observed in the phosphate ion concentration. These results indicate that a suitable in vitro response was achieved on a composite incorporating particulate glass-ceramic A–W with a particularly favorable response being observed on the AWPEX sample with 50 vol % Filler Content.

J A Juhasz - One of the best experts on this subject based on the ideXlab platform.

  • mechanical properties of glass ceramic a w polyethylene composites effect of Filler Content and particle size
    Biomaterials, 2004
    Co-Authors: J A Juhasz, Serena M Best, R A Brooks, Masakazu Kawashita, Noboru Miyata, Tadashi Kokubo, Takashi Nakamura, W Bonfield
    Abstract:

    Abstract Composites which comprise a bioactive Filler and ductile polymer matrix are desirable as implant materials since both their biological and mechanical properties can be tailored for a given application. In the present study three-point bending was used to characterise biomedical materials composed of glass-ceramic apatite–wollastonite (A–W) particulate reinforced polyethylene (PE) (denoted as AWPEX). The effects of Filler volume fraction, varied from 10 to 50 vol%, and average particle size, 4.4 and 6.7 μm, on the bending strength, yield strength, mode of fracture, Young's modulus and strain to failure were investigated. HAPEX™, a commercially used composite of hydroxyapatite and polyethylene, with a 40 vol% Filler Content, was used for comparison. Increasing the Filler Content caused an increase in Young's modulus, yield strength and bending strength, and a decreased strain to failure. When Filler particle size was increased, the Young's modulus, yield and bending strengths were found to be slightly reduced. A transition in fracture behaviour from ductile to brittle behaviour was observed in samples containing between 30 and 40 vol% Filler.

  • Mechanical properties of glass-ceramic A–W-polyethylene composites: effect of Filler Content and particle size
    Biomaterials, 2004
    Co-Authors: J A Juhasz, Serena M Best, R A Brooks, Masakazu Kawashita, Noboru Miyata, Tadashi Kokubo, Takashi Nakamura, W Bonfield
    Abstract:

    Abstract Composites which comprise a bioactive Filler and ductile polymer matrix are desirable as implant materials since both their biological and mechanical properties can be tailored for a given application. In the present study three-point bending was used to characterise biomedical materials composed of glass-ceramic apatite–wollastonite (A–W) particulate reinforced polyethylene (PE) (denoted as AWPEX). The effects of Filler volume fraction, varied from 10 to 50 vol%, and average particle size, 4.4 and 6.7 μm, on the bending strength, yield strength, mode of fracture, Young's modulus and strain to failure were investigated. HAPEX™, a commercially used composite of hydroxyapatite and polyethylene, with a 40 vol% Filler Content, was used for comparison. Increasing the Filler Content caused an increase in Young's modulus, yield strength and bending strength, and a decreased strain to failure. When Filler particle size was increased, the Young's modulus, yield and bending strengths were found to be slightly reduced. A transition in fracture behaviour from ductile to brittle behaviour was observed in samples containing between 30 and 40 vol% Filler.

  • apatite forming ability of glass ceramic apatite wollastonite polyethylene composites effect of Filler Content
    Journal of Materials Science: Materials in Medicine, 2003
    Co-Authors: J A Juhasz, Serena M Best, Masakazu Kawashita, Noboru Miyata, Tadashi Kokubo, W Bonfield, Takashi Nakamura
    Abstract:

    The bioactivity of a range of glass-ceramic apatite–wollastonite (A–W) – polyethylene composites (AWPEXs) with glass-ceramic A–W volume percentages ranging from 10 to 50, has been investigated in an acellular simulated body fluid (SBF) with ion concentrations similar to those of human blood plasma. The formation of a biologically active apatite layer on the composite surface after immersion in SBF was demonstrated by thin-film X-ray diffraction (TF-XRD) and field-emission scanning electron microscopy (FE-SEM). An apatite layer was formed on all the composites, with the rate of formation increasing with an increase in glass-ceramic A–W percentage. For composites with glass-ceramic A–W Filler Contents ≥30 vol %, the apatite layer was formed within 12 h of immersion, which is a comparable time for apatite formation on monolithic glass-ceramic A–W. Inductively coupled plasma atomic emission spectroscopy (ICP-AES) demonstrated that the apatite formation on AWPEX samples with 50 vol % Filler Content occurred in a manner similar to that seen on pure glass-ceramic A–W, in that the calcium, silicon, and magnesium ion concentrations increased and, conversely, a decrease was observed in the phosphate ion concentration. These results indicate that a suitable in vitro response was achieved on a composite incorporating particulate glass-ceramic A–W with a particularly favorable response being observed on the AWPEX sample with 50 vol % Filler Content.

  • Apatite-forming ability of glass-ceramic apatite–wollastonite – polyethylene composites: effect of Filler Content
    Journal of Materials Science: Materials in Medicine, 2003
    Co-Authors: J A Juhasz, Serena M Best, Masakazu Kawashita, Noboru Miyata, Tadashi Kokubo, W Bonfield, Takashi Nakamura
    Abstract:

    The bioactivity of a range of glass-ceramic apatite–wollastonite (A–W) – polyethylene composites (AWPEXs) with glass-ceramic A–W volume percentages ranging from 10 to 50, has been investigated in an acellular simulated body fluid (SBF) with ion concentrations similar to those of human blood plasma. The formation of a biologically active apatite layer on the composite surface after immersion in SBF was demonstrated by thin-film X-ray diffraction (TF-XRD) and field-emission scanning electron microscopy (FE-SEM). An apatite layer was formed on all the composites, with the rate of formation increasing with an increase in glass-ceramic A–W percentage. For composites with glass-ceramic A–W Filler Contents ≥30 vol %, the apatite layer was formed within 12 h of immersion, which is a comparable time for apatite formation on monolithic glass-ceramic A–W. Inductively coupled plasma atomic emission spectroscopy (ICP-AES) demonstrated that the apatite formation on AWPEX samples with 50 vol % Filler Content occurred in a manner similar to that seen on pure glass-ceramic A–W, in that the calcium, silicon, and magnesium ion concentrations increased and, conversely, a decrease was observed in the phosphate ion concentration. These results indicate that a suitable in vitro response was achieved on a composite incorporating particulate glass-ceramic A–W with a particularly favorable response being observed on the AWPEX sample with 50 vol % Filler Content.

W Bonfield - One of the best experts on this subject based on the ideXlab platform.

  • mechanical properties of glass ceramic a w polyethylene composites effect of Filler Content and particle size
    Biomaterials, 2004
    Co-Authors: J A Juhasz, Serena M Best, R A Brooks, Masakazu Kawashita, Noboru Miyata, Tadashi Kokubo, Takashi Nakamura, W Bonfield
    Abstract:

    Abstract Composites which comprise a bioactive Filler and ductile polymer matrix are desirable as implant materials since both their biological and mechanical properties can be tailored for a given application. In the present study three-point bending was used to characterise biomedical materials composed of glass-ceramic apatite–wollastonite (A–W) particulate reinforced polyethylene (PE) (denoted as AWPEX). The effects of Filler volume fraction, varied from 10 to 50 vol%, and average particle size, 4.4 and 6.7 μm, on the bending strength, yield strength, mode of fracture, Young's modulus and strain to failure were investigated. HAPEX™, a commercially used composite of hydroxyapatite and polyethylene, with a 40 vol% Filler Content, was used for comparison. Increasing the Filler Content caused an increase in Young's modulus, yield strength and bending strength, and a decreased strain to failure. When Filler particle size was increased, the Young's modulus, yield and bending strengths were found to be slightly reduced. A transition in fracture behaviour from ductile to brittle behaviour was observed in samples containing between 30 and 40 vol% Filler.

  • Mechanical properties of glass-ceramic A–W-polyethylene composites: effect of Filler Content and particle size
    Biomaterials, 2004
    Co-Authors: J A Juhasz, Serena M Best, R A Brooks, Masakazu Kawashita, Noboru Miyata, Tadashi Kokubo, Takashi Nakamura, W Bonfield
    Abstract:

    Abstract Composites which comprise a bioactive Filler and ductile polymer matrix are desirable as implant materials since both their biological and mechanical properties can be tailored for a given application. In the present study three-point bending was used to characterise biomedical materials composed of glass-ceramic apatite–wollastonite (A–W) particulate reinforced polyethylene (PE) (denoted as AWPEX). The effects of Filler volume fraction, varied from 10 to 50 vol%, and average particle size, 4.4 and 6.7 μm, on the bending strength, yield strength, mode of fracture, Young's modulus and strain to failure were investigated. HAPEX™, a commercially used composite of hydroxyapatite and polyethylene, with a 40 vol% Filler Content, was used for comparison. Increasing the Filler Content caused an increase in Young's modulus, yield strength and bending strength, and a decreased strain to failure. When Filler particle size was increased, the Young's modulus, yield and bending strengths were found to be slightly reduced. A transition in fracture behaviour from ductile to brittle behaviour was observed in samples containing between 30 and 40 vol% Filler.

  • apatite forming ability of glass ceramic apatite wollastonite polyethylene composites effect of Filler Content
    Journal of Materials Science: Materials in Medicine, 2003
    Co-Authors: J A Juhasz, Serena M Best, Masakazu Kawashita, Noboru Miyata, Tadashi Kokubo, W Bonfield, Takashi Nakamura
    Abstract:

    The bioactivity of a range of glass-ceramic apatite–wollastonite (A–W) – polyethylene composites (AWPEXs) with glass-ceramic A–W volume percentages ranging from 10 to 50, has been investigated in an acellular simulated body fluid (SBF) with ion concentrations similar to those of human blood plasma. The formation of a biologically active apatite layer on the composite surface after immersion in SBF was demonstrated by thin-film X-ray diffraction (TF-XRD) and field-emission scanning electron microscopy (FE-SEM). An apatite layer was formed on all the composites, with the rate of formation increasing with an increase in glass-ceramic A–W percentage. For composites with glass-ceramic A–W Filler Contents ≥30 vol %, the apatite layer was formed within 12 h of immersion, which is a comparable time for apatite formation on monolithic glass-ceramic A–W. Inductively coupled plasma atomic emission spectroscopy (ICP-AES) demonstrated that the apatite formation on AWPEX samples with 50 vol % Filler Content occurred in a manner similar to that seen on pure glass-ceramic A–W, in that the calcium, silicon, and magnesium ion concentrations increased and, conversely, a decrease was observed in the phosphate ion concentration. These results indicate that a suitable in vitro response was achieved on a composite incorporating particulate glass-ceramic A–W with a particularly favorable response being observed on the AWPEX sample with 50 vol % Filler Content.

  • Apatite-forming ability of glass-ceramic apatite–wollastonite – polyethylene composites: effect of Filler Content
    Journal of Materials Science: Materials in Medicine, 2003
    Co-Authors: J A Juhasz, Serena M Best, Masakazu Kawashita, Noboru Miyata, Tadashi Kokubo, W Bonfield, Takashi Nakamura
    Abstract:

    The bioactivity of a range of glass-ceramic apatite–wollastonite (A–W) – polyethylene composites (AWPEXs) with glass-ceramic A–W volume percentages ranging from 10 to 50, has been investigated in an acellular simulated body fluid (SBF) with ion concentrations similar to those of human blood plasma. The formation of a biologically active apatite layer on the composite surface after immersion in SBF was demonstrated by thin-film X-ray diffraction (TF-XRD) and field-emission scanning electron microscopy (FE-SEM). An apatite layer was formed on all the composites, with the rate of formation increasing with an increase in glass-ceramic A–W percentage. For composites with glass-ceramic A–W Filler Contents ≥30 vol %, the apatite layer was formed within 12 h of immersion, which is a comparable time for apatite formation on monolithic glass-ceramic A–W. Inductively coupled plasma atomic emission spectroscopy (ICP-AES) demonstrated that the apatite formation on AWPEX samples with 50 vol % Filler Content occurred in a manner similar to that seen on pure glass-ceramic A–W, in that the calcium, silicon, and magnesium ion concentrations increased and, conversely, a decrease was observed in the phosphate ion concentration. These results indicate that a suitable in vitro response was achieved on a composite incorporating particulate glass-ceramic A–W with a particularly favorable response being observed on the AWPEX sample with 50 vol % Filler Content.

Tadashi Kokubo - One of the best experts on this subject based on the ideXlab platform.

  • mechanical properties of glass ceramic a w polyethylene composites effect of Filler Content and particle size
    Biomaterials, 2004
    Co-Authors: J A Juhasz, Serena M Best, R A Brooks, Masakazu Kawashita, Noboru Miyata, Tadashi Kokubo, Takashi Nakamura, W Bonfield
    Abstract:

    Abstract Composites which comprise a bioactive Filler and ductile polymer matrix are desirable as implant materials since both their biological and mechanical properties can be tailored for a given application. In the present study three-point bending was used to characterise biomedical materials composed of glass-ceramic apatite–wollastonite (A–W) particulate reinforced polyethylene (PE) (denoted as AWPEX). The effects of Filler volume fraction, varied from 10 to 50 vol%, and average particle size, 4.4 and 6.7 μm, on the bending strength, yield strength, mode of fracture, Young's modulus and strain to failure were investigated. HAPEX™, a commercially used composite of hydroxyapatite and polyethylene, with a 40 vol% Filler Content, was used for comparison. Increasing the Filler Content caused an increase in Young's modulus, yield strength and bending strength, and a decreased strain to failure. When Filler particle size was increased, the Young's modulus, yield and bending strengths were found to be slightly reduced. A transition in fracture behaviour from ductile to brittle behaviour was observed in samples containing between 30 and 40 vol% Filler.

  • Mechanical properties of glass-ceramic A–W-polyethylene composites: effect of Filler Content and particle size
    Biomaterials, 2004
    Co-Authors: J A Juhasz, Serena M Best, R A Brooks, Masakazu Kawashita, Noboru Miyata, Tadashi Kokubo, Takashi Nakamura, W Bonfield
    Abstract:

    Abstract Composites which comprise a bioactive Filler and ductile polymer matrix are desirable as implant materials since both their biological and mechanical properties can be tailored for a given application. In the present study three-point bending was used to characterise biomedical materials composed of glass-ceramic apatite–wollastonite (A–W) particulate reinforced polyethylene (PE) (denoted as AWPEX). The effects of Filler volume fraction, varied from 10 to 50 vol%, and average particle size, 4.4 and 6.7 μm, on the bending strength, yield strength, mode of fracture, Young's modulus and strain to failure were investigated. HAPEX™, a commercially used composite of hydroxyapatite and polyethylene, with a 40 vol% Filler Content, was used for comparison. Increasing the Filler Content caused an increase in Young's modulus, yield strength and bending strength, and a decreased strain to failure. When Filler particle size was increased, the Young's modulus, yield and bending strengths were found to be slightly reduced. A transition in fracture behaviour from ductile to brittle behaviour was observed in samples containing between 30 and 40 vol% Filler.

  • apatite forming ability of glass ceramic apatite wollastonite polyethylene composites effect of Filler Content
    Journal of Materials Science: Materials in Medicine, 2003
    Co-Authors: J A Juhasz, Serena M Best, Masakazu Kawashita, Noboru Miyata, Tadashi Kokubo, W Bonfield, Takashi Nakamura
    Abstract:

    The bioactivity of a range of glass-ceramic apatite–wollastonite (A–W) – polyethylene composites (AWPEXs) with glass-ceramic A–W volume percentages ranging from 10 to 50, has been investigated in an acellular simulated body fluid (SBF) with ion concentrations similar to those of human blood plasma. The formation of a biologically active apatite layer on the composite surface after immersion in SBF was demonstrated by thin-film X-ray diffraction (TF-XRD) and field-emission scanning electron microscopy (FE-SEM). An apatite layer was formed on all the composites, with the rate of formation increasing with an increase in glass-ceramic A–W percentage. For composites with glass-ceramic A–W Filler Contents ≥30 vol %, the apatite layer was formed within 12 h of immersion, which is a comparable time for apatite formation on monolithic glass-ceramic A–W. Inductively coupled plasma atomic emission spectroscopy (ICP-AES) demonstrated that the apatite formation on AWPEX samples with 50 vol % Filler Content occurred in a manner similar to that seen on pure glass-ceramic A–W, in that the calcium, silicon, and magnesium ion concentrations increased and, conversely, a decrease was observed in the phosphate ion concentration. These results indicate that a suitable in vitro response was achieved on a composite incorporating particulate glass-ceramic A–W with a particularly favorable response being observed on the AWPEX sample with 50 vol % Filler Content.

  • Apatite-forming ability of glass-ceramic apatite–wollastonite – polyethylene composites: effect of Filler Content
    Journal of Materials Science: Materials in Medicine, 2003
    Co-Authors: J A Juhasz, Serena M Best, Masakazu Kawashita, Noboru Miyata, Tadashi Kokubo, W Bonfield, Takashi Nakamura
    Abstract:

    The bioactivity of a range of glass-ceramic apatite–wollastonite (A–W) – polyethylene composites (AWPEXs) with glass-ceramic A–W volume percentages ranging from 10 to 50, has been investigated in an acellular simulated body fluid (SBF) with ion concentrations similar to those of human blood plasma. The formation of a biologically active apatite layer on the composite surface after immersion in SBF was demonstrated by thin-film X-ray diffraction (TF-XRD) and field-emission scanning electron microscopy (FE-SEM). An apatite layer was formed on all the composites, with the rate of formation increasing with an increase in glass-ceramic A–W percentage. For composites with glass-ceramic A–W Filler Contents ≥30 vol %, the apatite layer was formed within 12 h of immersion, which is a comparable time for apatite formation on monolithic glass-ceramic A–W. Inductively coupled plasma atomic emission spectroscopy (ICP-AES) demonstrated that the apatite formation on AWPEX samples with 50 vol % Filler Content occurred in a manner similar to that seen on pure glass-ceramic A–W, in that the calcium, silicon, and magnesium ion concentrations increased and, conversely, a decrease was observed in the phosphate ion concentration. These results indicate that a suitable in vitro response was achieved on a composite incorporating particulate glass-ceramic A–W with a particularly favorable response being observed on the AWPEX sample with 50 vol % Filler Content.

Noboru Miyata - One of the best experts on this subject based on the ideXlab platform.

  • mechanical properties of glass ceramic a w polyethylene composites effect of Filler Content and particle size
    Biomaterials, 2004
    Co-Authors: J A Juhasz, Serena M Best, R A Brooks, Masakazu Kawashita, Noboru Miyata, Tadashi Kokubo, Takashi Nakamura, W Bonfield
    Abstract:

    Abstract Composites which comprise a bioactive Filler and ductile polymer matrix are desirable as implant materials since both their biological and mechanical properties can be tailored for a given application. In the present study three-point bending was used to characterise biomedical materials composed of glass-ceramic apatite–wollastonite (A–W) particulate reinforced polyethylene (PE) (denoted as AWPEX). The effects of Filler volume fraction, varied from 10 to 50 vol%, and average particle size, 4.4 and 6.7 μm, on the bending strength, yield strength, mode of fracture, Young's modulus and strain to failure were investigated. HAPEX™, a commercially used composite of hydroxyapatite and polyethylene, with a 40 vol% Filler Content, was used for comparison. Increasing the Filler Content caused an increase in Young's modulus, yield strength and bending strength, and a decreased strain to failure. When Filler particle size was increased, the Young's modulus, yield and bending strengths were found to be slightly reduced. A transition in fracture behaviour from ductile to brittle behaviour was observed in samples containing between 30 and 40 vol% Filler.

  • Mechanical properties of glass-ceramic A–W-polyethylene composites: effect of Filler Content and particle size
    Biomaterials, 2004
    Co-Authors: J A Juhasz, Serena M Best, R A Brooks, Masakazu Kawashita, Noboru Miyata, Tadashi Kokubo, Takashi Nakamura, W Bonfield
    Abstract:

    Abstract Composites which comprise a bioactive Filler and ductile polymer matrix are desirable as implant materials since both their biological and mechanical properties can be tailored for a given application. In the present study three-point bending was used to characterise biomedical materials composed of glass-ceramic apatite–wollastonite (A–W) particulate reinforced polyethylene (PE) (denoted as AWPEX). The effects of Filler volume fraction, varied from 10 to 50 vol%, and average particle size, 4.4 and 6.7 μm, on the bending strength, yield strength, mode of fracture, Young's modulus and strain to failure were investigated. HAPEX™, a commercially used composite of hydroxyapatite and polyethylene, with a 40 vol% Filler Content, was used for comparison. Increasing the Filler Content caused an increase in Young's modulus, yield strength and bending strength, and a decreased strain to failure. When Filler particle size was increased, the Young's modulus, yield and bending strengths were found to be slightly reduced. A transition in fracture behaviour from ductile to brittle behaviour was observed in samples containing between 30 and 40 vol% Filler.

  • apatite forming ability of glass ceramic apatite wollastonite polyethylene composites effect of Filler Content
    Journal of Materials Science: Materials in Medicine, 2003
    Co-Authors: J A Juhasz, Serena M Best, Masakazu Kawashita, Noboru Miyata, Tadashi Kokubo, W Bonfield, Takashi Nakamura
    Abstract:

    The bioactivity of a range of glass-ceramic apatite–wollastonite (A–W) – polyethylene composites (AWPEXs) with glass-ceramic A–W volume percentages ranging from 10 to 50, has been investigated in an acellular simulated body fluid (SBF) with ion concentrations similar to those of human blood plasma. The formation of a biologically active apatite layer on the composite surface after immersion in SBF was demonstrated by thin-film X-ray diffraction (TF-XRD) and field-emission scanning electron microscopy (FE-SEM). An apatite layer was formed on all the composites, with the rate of formation increasing with an increase in glass-ceramic A–W percentage. For composites with glass-ceramic A–W Filler Contents ≥30 vol %, the apatite layer was formed within 12 h of immersion, which is a comparable time for apatite formation on monolithic glass-ceramic A–W. Inductively coupled plasma atomic emission spectroscopy (ICP-AES) demonstrated that the apatite formation on AWPEX samples with 50 vol % Filler Content occurred in a manner similar to that seen on pure glass-ceramic A–W, in that the calcium, silicon, and magnesium ion concentrations increased and, conversely, a decrease was observed in the phosphate ion concentration. These results indicate that a suitable in vitro response was achieved on a composite incorporating particulate glass-ceramic A–W with a particularly favorable response being observed on the AWPEX sample with 50 vol % Filler Content.

  • Apatite-forming ability of glass-ceramic apatite–wollastonite – polyethylene composites: effect of Filler Content
    Journal of Materials Science: Materials in Medicine, 2003
    Co-Authors: J A Juhasz, Serena M Best, Masakazu Kawashita, Noboru Miyata, Tadashi Kokubo, W Bonfield, Takashi Nakamura
    Abstract:

    The bioactivity of a range of glass-ceramic apatite–wollastonite (A–W) – polyethylene composites (AWPEXs) with glass-ceramic A–W volume percentages ranging from 10 to 50, has been investigated in an acellular simulated body fluid (SBF) with ion concentrations similar to those of human blood plasma. The formation of a biologically active apatite layer on the composite surface after immersion in SBF was demonstrated by thin-film X-ray diffraction (TF-XRD) and field-emission scanning electron microscopy (FE-SEM). An apatite layer was formed on all the composites, with the rate of formation increasing with an increase in glass-ceramic A–W percentage. For composites with glass-ceramic A–W Filler Contents ≥30 vol %, the apatite layer was formed within 12 h of immersion, which is a comparable time for apatite formation on monolithic glass-ceramic A–W. Inductively coupled plasma atomic emission spectroscopy (ICP-AES) demonstrated that the apatite formation on AWPEX samples with 50 vol % Filler Content occurred in a manner similar to that seen on pure glass-ceramic A–W, in that the calcium, silicon, and magnesium ion concentrations increased and, conversely, a decrease was observed in the phosphate ion concentration. These results indicate that a suitable in vitro response was achieved on a composite incorporating particulate glass-ceramic A–W with a particularly favorable response being observed on the AWPEX sample with 50 vol % Filler Content.