Phosphorus Research Bulletin
Online ISSN : 1882-2363
Print ISSN : 0918-4783
ISSN-L : 0918-4783
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Volume 31
Displaying 1-10 of 10 articles from this issue
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  • DEMINERALIZED DENTIN MATRIX WITH ARTIFICIAL PERFORATIONS FOR BONE REGNERATION IN CRITICAL DEFECTS OF ADULT SHEEP
    ARAFAT KABIR, MASARU MURATA, TOSHIYUKI AKAZAWA, KATSUHUSA YAMADA, MANA ...
    2016 Volume 31 Pages 1-3
    Published: 2016
    Released on J-STAGE: October 09, 2016
    DOIhttps://doi.org/10.3363/prb.31.1
    JOURNAL FREE ACCESS
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    A vital tooth-derived demineralized dentin matrix (DDM) is defined as acid-insoluble, cross-linked collagen with growth factors. The objective of this study is to evaluate the feasibility of the perforated-DDM for bone regeneration. Thirty perforations were added to the human vital wisdom tooth after the removal of enamel portion. The modified tooth was partially demineralized in 0.34 N HNO3 for 30 min and grafted into the critical defect of sheep iliac to evaluate bone regeneration. Sheep were sacrificed for μ-CT and histological evaluation at 2 and 4 months after the graft. New bone was connected directly with the grafted DDM at 2 months. The volume of new bone was comparable with the μ-CT, 3D, and the histological findings at 2 and 4 months. The amount of new bone tissue in the critical defects at 4 months was higher than that at 2 months. The results revealed that the human tooth-derived block material with artificial porous structure, the perforated-DDM, successfully contributed to bone ingrowth as the unique scaffold. This novel human tooth-derived scaffold may be a promising biomaterial to induce bone regeneration in the tri-cortical critical-sized bone defects.
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  • SYNTHESIS OF HYDROXYAPATITE PARTICLES INTENDED FOR THE SELECTIVE ADSORPTION OF BASIC PROTEINS
    Toshio Nagasaki, Fukue Nagata, Makoto Sakurai, Katsuya Kato
    2016 Volume 31 Pages 4-8
    Published: 2016
    Released on J-STAGE: October 09, 2016
    DOIhttps://doi.org/10.3363/prb.31.4
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    In this study, we report a simple method for synthesizing HAp particles intended for the selective adsorption of basic proteins. HAp particles for the adsorption of basic proteins were prepared from a mixture of calcium acetate and diammonium hydrogen phosphate solutions, both adjusted at pH 10 (HAp-pH10) and a non-adjusted pH (HAp-none). For HAp-none, the amount of bovine serum albumin (BSA, an acidic protein) adsorbed per unit specific surface area was larger than the amount of lysozyme (LSZ, a basic protein) adsorbed. The ratio of the amounts of protein adsorption, i.e., LSZ/BSA, was 0.32 for HAp-none. The amount of LSZ adsorbed on HAp-pH10 was larger than those for BSA. The ratio of LSZ/BSA was 2.38 on HAp-pH10 aged for 1 h. An increase in the aging time (72 h) caused an increase in LSZ/BSA to 3.17.
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  • THE EFFECTS OF SBF CONDITIONS ON ENCAPSULATION OF AGAROSE GEL WITH HYDROXYAPATITE MICROCAPSULES
    Hiroki Nakamura, Michiaki Sakaguchi, Takeshi Yabutsuka, Shigeomi Takai ...
    2016 Volume 31 Pages 9-14
    Published: 2016
    Released on J-STAGE: October 09, 2016
    DOIhttps://doi.org/10.3363/prb.31.9
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    By raising the temperature or the pH of an acellular simulated body fluid (SBF), nanoparticles of amorphous calcium phosphate are precipitated. The nanoparticles are highly active to induce hydroxyapatite formation in body fluid or SBF. In this study, the authors fabricated hydroxyapatite microcapsules encapsulating an agarose gel by using the nanoparticles and examined the effects of the pH and the concentrations of SBF on the microcapsules formation process. Increase in ion concentrations or raising pH of SBF caused the acceleration of the microcapsules formation.
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  • EFFECTS OF SANDBLASTING CONDITIONS IN PREPARATION OF BIOACTIVE STAINLESS STEELS BY THE FUNCTION OF APATITE NUCLEI
    Takeshi Yabutsuka, Ryoki Karashima, Shigeomi Takai, Takeshi Yao
    2016 Volume 31 Pages 15-19
    Published: 2016
    Released on J-STAGE: October 09, 2016
    DOIhttps://doi.org/10.3363/prb.31.15
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    We formed many micropores on the surfaces of stainless steel (SUS) substrates by sandblasting method using alumina particles with 14 μm or 3 μm for average particle size and apatite nucleus (AN) treatment was operated. By these treatments, we provided bioactivity to the SUS substrates. We evaluated apatite-forming ability of the SUS substrate by soaking in a simulated body fluid. Apatite formation was induced on the surface of the substrate within 1 day. High adhesive strength of apatite layer was achieved by a mechanical interlocking effect between the apatite layer and the substrate. The adhesive strength was related to the size of the grinding particles in the sandblasting process.
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  • PREPARATION OF Sr-CONTAINING BONE LIKE APATITE CEMENT
    Takahito Kasai, Tomohiro Uchino
    2016 Volume 31 Pages 20-23
    Published: 2016
    Released on J-STAGE: October 09, 2016
    DOIhttps://doi.org/10.3363/prb.31.20
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    Amorphous calcium phosphate (ACP) is a known precursor of apatite, which is one of the main components of human bone. Synthesized ACP transforms into low-crystallinity hydroxyapatite (HAp) around body temperature. Thus, if low-crystallinity calcium phosphate cement, containing active ingredients for bone repair, can be prepared at around 0°C, it is expected to be a suitable material for the controlled-release of active ingredients. Sr was reported to promote a cytokine, which inhibited the formation of osteoclasts. Thus, Sr-doped ACP is expected to be a controlled-release material and can promote bone formation. In this study, we synthesized Sr-doped ACP powder by wet synthesis, and prepared Sr-doped calcium phosphate cement. The cement has potential for use as a new type of bone substitute.
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  • EFFECT OF PRE-CRYSTALLIZATION ON LITHIUM DISILICATE GLASS-CERAMICS FABRICATED BY DIFFERENT PROCESSES
    Naruporn Monmaturapoj, Autcharaporn Sri-On, Thossapol Chunkiri
    2016 Volume 31 Pages 24-30
    Published: 2016
    Released on J-STAGE: October 09, 2016
    DOIhttps://doi.org/10.3363/prb.31.24
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    SiO2-Li2O-K2O-Al2O3-P2O5 based lithium disilicate glass ceramic was prepared and fabricated into dental crowns. The influence of factors such as pre-crystallization temperature and fabrication technique on the phase formation and morphology of the glass ceramic was investigated. Differential thermal analysis (DTA), X-ray diffraction (XRD), scanning and transmission electron microscopies (SEM and TEM) were performed to determine the thermal properties, the phase formation and microstructure of the samples, respectively. The composition of lithium disilicate glass ceramic could be fabricated into dental crowns through the hot-pressing and CAD/CAM techniques. Similarities in phase formation have been revealed on the dental crown samples after fabrication by both methods. The dental crown samples fabricated by the CAD/CAM technique exhibited significantly finer needle-like crystals of lithium disilicate. The pre-cerammed ingots and fabrication technique have no significant change on the phase formation; however, they play important roles in changing the morphology of the samples in this study.
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  • INVESTIGATION OF EFFECTIVE PROCEDURES IN FABRICATION OF BIOACTIVE PEEK USING THE FUNCTION OF APATITE NUCLEI
    Keito Fukushima, Takeshi Yabutsuka, Shigeomi Takai, Takeshi Yao
    2016 Volume 31 Pages 31-37
    Published: 2016
    Released on J-STAGE: October 09, 2016
    DOIhttps://doi.org/10.3363/prb.31.31
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    We made micropores on the surface of a polyether ether ketone (PEEK) by immersing in sulfuric acid. In order to provide bioactivity to PEEK, we treated the surfaces of the specimens with glow-discharge in O2 gas atmosphere and precipitated Apatite Nucleus (AN) in the micropores. We evaluated apatite-forming ability of the specimens by using SBF and measured adhesive strength of formed apatite layer. In this study, we researched which treatment is effective to give bioactivity to PEEK.
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  • SYNTHESIS and PROPERTIES of NON-RIGID CALCIUM PHOSPHATE CEMENT CONTAINING CHITOSAN
    YOSHIYUKI YOKOGAWA, TOMOHIRO MURATA, HIROKI YAMADA, KENTARO FUJII, KEN ...
    2016 Volume 31 Pages 38-43
    Published: 2016
    Released on J-STAGE: October 09, 2016
    DOIhttps://doi.org/10.3363/prb.31.38
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    Calcium phosphate cement (CPC) has biocompatibility and osteoconductive property, but it has some drawbacks, such as wash-out and rigid and brittle properties. Such drawbacks can be overcome by fast-setting and gelation of the CPC paste. The CPC powder is a mixture of tetracalcium phosphate and dicalcium phosphate dehydrate. A low or medium molecular weight chitosan (low- or med-chitosan) and malic acid solution were used in the liquid phase to develop fast-setting and high work-of-fracture CPC materials. The incorporation of 1.25 - 2.5 wt% chitosan increased a tripled work-of-fracture to 12.0 kJ/m2 when not using chitosan. The setting time was 2.8±0.3 min and 5.5±0.5 min when 2.5 wt% low- or med-chitosan was used, respectively. The "non-rigid” and “fast-setting" CPC cement was successfully obtained by adding chitosan and malic acid to the liquid phase, and the incorporation of med-chitosan may produce a high work-of-fracture and stable CPC with a desirable setting time.
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