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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Journal of materials science 7 (1996), S. 317-322 
    ISSN: 1573-4838
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Technology
    Notes: Abstract A non-decay type fast-setting calcium phosphate cement (nd-FSCPC) has been described, which did not decay but set within approximately 5–6 min even when the paste was immersed in serum immediately after mixing, and which forms hydroxyapatite as its end product. nd-FSCPC was produced by adding sodium alginate to the liquid phase of the base cement FSCPC. Sodium alginate forms a water-insoluble gel, and reduces the process of fluid penetration into the paste which is the cause of decay. The aim of this investigation was to confirm the mechanism of the non-decaying behaviour of nd-FSCPC proposed in a previous paper, using another chemical with properties similar to those of sodium alginate. Also, it was intended to further improve both the mechanical properties and tissue response of nd-FSCPC. Chitosan, which also forms a water-insoluble gel in the presence of calcium ions and has been reported to have pharmacologically beneficial effects on osteoconductivity, was added to the liquid phase of the base cement FSCPC. The cement thus prepared showed behaviour similar to that of nd-FSCPC using sodium alginate. The cement paste did not decay but set within approximately 5–6 min even when immersed in serum immediately after mixing. DTS value of the set mass was approximately 3–4 MPa, slightly lower than that of nd-FSCPC using sodium alginate, and no inhibitory effect was observed for the transformation of cement component to apatite within the range used in this investigation (up to 1.5%). Therefore, it was concluded that the mechanism of non-decaying behaviour was, at least in part, reduction of fluid penetration into the cement paste. nd-FSCPC using chitosan showed slightly poorer mechanical properties than that using sodium alginate. However, pharmacological effects such as osteoconductivity could be expected in nd-FSCPC using chitosan. Thus, this cement may be useful as a more sophisticated bioactive cement than nd-FSCPC using sodium alginate.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1573-4838
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Technology
    Notes: Abstract To compare the surface properties of calcium-ion (Ca2+)-implanted titanium with those of titanium and to investigate the mechanism of bone conductivity of Ca2+-implanted titanium, amounts of hydroxyl radical of Ca2+-implanted titanium and titanium were estimated. Also, the point of zero charge (p.z.c.) of oxide constituting surface oxides of Ca2+-implanted titanium and titanium was determined. Results showed that the amount of active hydroxyl radical on Ca2+-implanted titanium was found to be significantly larger than that on titanium, indicating that the number of electric-charging sites of Ca2+-implanted titanium in electrolyte is more than that of titanium. The p.z.c. values of rutile (TiO2), anatase (TiO2), and perovskite (CaTiO3), were estimated to be 4.6, 5.9, and 8.1, respectively. Thus, Ca2+-implanted titanium surface is charged more positively in bioliquid than titanium, accelerating the adsorption of phosphate ions. © 1998 Chapman & Hall
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    Journal of Biomedical Materials Research 37 (1997), S. 457-464 
    ISSN: 0021-9304
    Keywords: biocompatibility ; bone ; calcium phosphate cement ; fast-setting ; hydroxyapatite ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Notes: Fast-setting calcium phosphate cement (FSCPC) is a promising new bioactive cement with a significantly short setting time (approximately 5-6 min) compared to conventional calcium phosphate cement (c-CPC) (30-60 min) at physiologic temperatures. As a result of its ability to set quickly, it is applicable in surgical procedures where fast setting is required. In this study, FSCPC was implanted in rat tibiae to evaluate tissue response and biocompatibility. FSCPC was converted to hydroxyapatite (HAP) in bone faster than c-CPC in the first 6 h. By 24 h, significant amounts of both FSCPC and c-CPC had been converted to HAP. The conversion of FSCPC into HAP further proceeded gradually, reaching 100% within 8 weeks. Infrared spectroscopic analysis disclosed the deposition of B-type carbonate apatite, which is a biological apatite contained in human dentin or bone, on the surface of the FSCPC. Histologically, FSCPC showed a tissue response similar to that of c-CPC. A slight inflammatory reaction was observed in the soft tissue apposed to both cements in the early period, and new bone was formed along the surface of the FSCPC at the adjacent bone. However, no resorption of either cement by osteoclasts or macrophages was observed within 8 weeks. We conclude that FSCPC is superior to c-CPC in clinical applications in oral and maxillofacial, orthopedic, plastic, and reconstructive surgery, since it shows a faster setting time and higher mechanical strength in the early period that are required in these surgical procedures, as well as osteoconductivity and excellent biocompatibility similar to that of c-CPC. © 1997 John Wiley & Sons, Inc. J Biomed Mater Res, 37, 457-464, 1997.
    Additional Material: 11 Ill.
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  • 4
    ISSN: 0021-9304
    Keywords: antibiotics ; calcium phosphate cement ; drug delivery system ; hydroxyapatite ; anti-washout type ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Notes: The effect of added antibiotics on the basic properties of anti-washout-type fast-setting calcium phosphate cement (aw-FSCPC) was investigated in a preliminary evaluation of aw-FSCPC containing drugs. Flomoxef sodium was employed as the antibiotic and was incorporated into the powder-phase aw-FSCPC at up to 10%. The setting time, consistency, wet diametral tensile strength (DTS) value, and porosity were measured for aw-FSCPC containing various amounts of flomoxef sodium. X-ray diffraction (XRD) analysis was also conducted for the identification of products. To evaluate the drug-release profile, set aw-FSCPC was immersed in saline and the released flomoxef sodium was determined at regular intervals. The spread area of the cement paste as an index of consistency of the cement increased progressively with the addition of flomoxef sodium, and it doubled when the aw-FSCPC contained 8% flomoxef sodium. In contrast, the wet DTS value decreased with increase in flomoxef sodium content. Bulk density measurement and scanning electron microscopic observation revealed that the set mass was more porous with the amount of flomoxef sodium contained in the aw-FSCPC. The XRD analysis revealed that formation of hydroxyapatite (HAP) from aw-FSCPC was reduced even after 24 h, when the aw-FSCPC contained flomoxef sodium at ≥6%. Therefore, the decrease of wet DTS value was thought to be partly the result of the increased porosity and inhibition of HAP formation in aw-FSCPC containing large amounts of flomoxef sodium. The flomoxef sodium release from aw-FSCPC showed the typical profile observed in a skeleton-type drug delivery system (DDS). The rate of drug release from aw-FSCPC can be controlled by changing the concentration of sodium alginate. Although flomoxef sodium addition has certain disadvantageous effects on the basic properties of aw-FSCPC, we conclude that aw-FSCPC is a good candidate for potential use as a DDS carrier that may be useful in surgical operations. © 1998 John Wiley & Sons, Inc. J Biomed Mater Res, 39, 308-316, 1998.
    Additional Material: 7 Ill.
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  • 5
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    Journal of Biomedical Materials Research 34 (1997), S. 273-278 
    ISSN: 0021-9304
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Notes: The surface of titanium was modified in calcium-ion-containing solutions to improve bone conductivity. Three kinds of aqueous solutions for the modification were prepared using calcium nitrate, calcium chloride, and calcium oxide. The pH values of the solutions were 3.9, 7.4, and 12.6, respectively. At first, anatase powder was immersed in the solutions for 7 days to confirm the effect of the solutions on the modification. As a result, calcium titanate was formed on the anatase powder, indicating that the titanium surface was possibly modified by the solutions. Titanium plates were then immersed in the solutions at ambient temperature for 7 days, washed by deionized water, and dried. X-ray photo-electron spectroscopy of surface-modified titanium revealed that the surface-modified layer contained calcium hydroxide and/or calcium titanate. The surface-modified layer in which titanium was modified was thickest in this order: calcium oxide, calcium chloride, and calcium nitrate solutions. Apatite was formed on the surface-modified titanium in Hanks' solution while apatite was undetected on unmodified titanium. Therefore, the surface modification of titanium may improve bone conductivity. The amount of apatite corresponded to the thickness of the surface-modified layer and the amount of calcium in the layer. © 1997 John Wiley & Sons, Inc.
    Additional Material: 6 Ill.
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  • 6
    ISSN: 0021-9304
    Keywords: calcium phosphate cement ; non-decay type ; putty ; sodium alginate ; hydroxyapatite ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Notes: A hydroxyapatite [(HAP) Ca10(PO4)6(OH)2] putty that behaves like a putty or self-curing resin was made by increasing the amount of sodium alginate in non-decay type fast-setting calcium phosphate cement (nd-FSCPC). nd-FSCPC became viscous as the sodium alginate concentration was increased. The best handling properties were obtained when nd-FSCPC contained 8% sodium alginate in its liquid phase. When a 2-kg glass plate was placed on the paste, HAP putty spread to form an area three times that of FSCPC paste. Thus, HAP putty is expected to be easier to use than FSCPC in the filling of bone defects. HAP putty did not decay; in fact, it set within approximately 20 min when immersed in distilled water immediately after mixing. The wet diametral tensile strength value of HAP putty was approximately 12 MPa after 24 h, the same as that for nd-FSCPC containing 0.5% sodium alginate in its liquid phase, or FSCPC that is free from sodium alginate. The elements constituting set HAP putty were examined using powder X-ray diffraction and found to be predominantly apatitic minerals after 24 h. Since the handling properties of a putty or self-curing resinlike cement are very useful in certain surgical procedures, HAP putty made by increasing the sodium alginate concentration in nd-FSCPC is potentially a valuable new biomaterial for use in plastic and reconstructive surgery, as well as oral and maxillofacial surgery. © 1997 John Wiley & Sons, Inc. J Biomed Mater Res, 36, 393-399, 1997.
    Additional Material: 8 Ill.
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  • 7
    Publication Date: 2022-02-01
    Print ISSN: 0304-3894
    Electronic ISSN: 1873-3336
    Topics: Chemistry and Pharmacology , Energy, Environment Protection, Nuclear Power Engineering , Technology
    Published by Elsevier
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