Masaharu Nakagawa
Kyushu University
Analytical chemistryNuclear chemistryPrecipitation hardeningComposite materialIndentation hardnessPowder diffractionChemistryMetallurgyMaterials scienceMineralogyCorrosionPhosphateApatiteCalcium carbonateAlloyCalciteFluorideCarbonate apatiteChemical engineeringPhase (matter)TitaniumCalciumPorosityCrystal twinningCrystallographyTitanium alloy
Publications 58
#1Waleed Elshahawy (Tanta University)H-Index: 5
#2Ikuya Watanabe (Nagasaki University)H-Index: 13
Last. P. Kramer (Texas A&M Health Science Center)H-Index: 1
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Abstract Background/Purpose This study investigated the effect of hydrothermal treatment with calcium chloride (CaCl2) solutions on fibroblast attachment and proliferation to titanium implants in the presence and absence of fetal bovine serum. Materials and methods Pure titanium specimens were prepared, polished (1500 grit), cleaned with ethanol, hydrothermally treated with CaCl2 solutions at 200 °C for 24 h (Ti–CaCl2). Two concentrations of CaCl2 solution were used (Ti–CaCl2 10 mM/L and Ti–CaCl...
1 CitationsSource
#1L. T. Bang (Kyushu University)H-Index: 10
#2Giichiro Kawachi (Kyushu University)H-Index: 10
Last. Radzali Othman (Universiti Sains Malaysia)H-Index: 18
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Poly(e-caprolactone) (PCL)/silicon-substituted carbonate apatite (Si-CO3Ap) composite derived from the interconnected porous Si-CO3Ap reinforced with molten PCL was prepared. PCL was used to improve the mechanical properties of a porous apatite by a simple polymer infiltration method, in which the molten PCL was deposited through the interconnected channel of porous Si-CO3Ap. The PCL covered and penetrated into the pores of the Si-CO3Ap to form an excellent physical interaction with Si-CO3Ap lea...
5 CitationsSource
#1Xingling Shi (Kyushu University)H-Index: 2
#2Masaharu NakagawaH-Index: 17
Last. Alireza Valanezhad (Kyushu University)H-Index: 8
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#1Xingling Shi (Kyushu University)H-Index: 2
#2Masaharu Nakagawa (Kyushu University)H-Index: 17
Last. Kunio Ishikawa (Kyushu University)H-Index: 53
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Surface modification on titanium was carried out in order to improve its bioactivity. Pure titanium was hydrothermally treated in distilled water and 0.1 M MgCl2 solutions at 200°C for 24 h. Surface morphology, roughness, wettability and chemical composition were characterized before and after treatment. Bovine serum albumin was used as model to study protein adsorption. MC3T3-E1 cells were cultured and initial cell attachment, morphology, proliferation were evaluated. After hydrothermal treatme...
41 CitationsSource
To achieve osteoconductivity, Ti–0.5Pt and Ti–6Al–4V–0.5Pt alloys were hydrothermally treated at 200°C in 10 mmol/l CaCl2 aqueous solution for 24 h (HT-treatment). We conducted histological investigations of the HT-treated materials by using Wistar strain rats (SD rats) to evaluate the usefulness of the treatment. To measure the bone bond strength, the specimens were implanted in the tibia of SD rats, and a pull-out test was conducted. From the early postoperative stages, direct bone contact was...
6 CitationsSource
#1Yali Cheng (Kyushu University)H-Index: 1
#2Takako Sakai (Kyushu University)H-Index: 9
Last. Yoshihiro Terada (Kyushu University)H-Index: 21
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This study examined the ability of a photocatalyst mixed in a denture base resin to decompose organic substances which adhered to the denture base resin surface. The photocatalyst was mixed with denture base resin at concentrations of 0, 5, 10, and 15% (w/w). Decomposition test, bending test, and surface roughness measurement were performed at 1, 7, 30, 90, and 180 days after polymerization. Decomposition ability was evaluated based on the residual amount of methylene blue (MB) dissolved in etha...
13 CitationsSource
#1Yoong Lee (SKKU: Sungkyunkwan University)H-Index: 7
#2Yeong Min Hahm (DU: Dankook University)H-Index: 3
Last. Kunio IshikawaH-Index: 53
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Human bone mineral is different in composition from stoichiometric hydroxyapatite (Ca 10 (PO 4 ) 6 (OH) 2 ) in that it contains additional ions, of which CO 3 2- is the most abundant species. Two macroporous carbonate-substituted hydroxyapatite (CHA) scaffolds were prepared by treating a macroporous CaCO 3 column (porosity, 88%; pore and hole size, 160 and 71 μm), prepared in this study, hydrothermally at 120 °C in 1 M phosphate solutions of (NH 4 ) 2 HPO 4 and K 2 HPO 4 . Especially, it was fou...
4 CitationsSource
#1Xin Lin (Kyushu University)H-Index: 4
#2Shigeki Matsuya (Fukuoka Dental College)H-Index: 27
Last. Kunio Ishikawa (Kyushu University)H-Index: 53
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We have reported that low-crystalline porous calcite block, which is useful as a bone substitute or a source material to prepare apatite-type bone fillers could be fabricated by exposing calcium hydroxide compact to carbon dioxide gas saturated with water vapor. In the present study, we investigated the effect of molding pressure on the transformation of calcium hydroxide into calcite and the mechanical strength of the carbonated compact. Transformation into calcite was almost completed within 7...
27 CitationsSource
#1Yoshinari Matono (Kyushu University)H-Index: 5
#2Masaharu Nakagawa (Kyushu University)H-Index: 17
Last. Yoshihiro Terada (Kyushu University)H-Index: 21
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Purpose: As for commercially pure titanium (CP-Ti) and titanium alloys (Ti-6Al-4V, Ti-6Al-7Nb), when fluoride exists in an acidic environment, it is known to corrode from recent research. However, it is also reported that the corrosion resistance improves when small amount of platinum is added to pure titanium. The purpose of this study is to examine the corrosion behavior of CP-Ti, Ti-6Al-4V, Ti-6Al-7Nb, and high corrosion Ti-0.5Pt alloy when a fluoride added to the acidic environment produced ...
4 CitationsSource
#1Hanae Wakae (Kyushu University)H-Index: 3
#2Akari Takeuchi (Kyushu University)H-Index: 11
Last. Ishikawa Kunio (Kyushu University)H-Index: 5
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We have previously reported that the carbonate apatite (CAP) foam that has similarities in both inorganic chemical composition and morphology to cancellous bone could be prepared from α-tricalcium phosphate (α-TCP) foam by the hydrothermal treatment with Na2CO3 at 200°C for 24 hrs. However, the crystallinity of the CAP foam was much higher than that of bone. In order to prepare CAP foam similar to cancellous bone in crystallinity as well as its inorganic composition and morphology, this study at...
2 CitationsSource