Beta tricalcium phosphate (β-Ca3(PO4)2, β-TCP) mixed with gypsum (CaSO4・2H2O) was heated at 1300°C and 1400°C. The resulting products were characterized by DTA, XRD, FTIR, EDX and hydration reactivity. An inhibition effect on the transition of the low temperature form β to high temperature form α was observed with increasing the amount of gypsum. The substitution of SO4 for PO4 was suggested from increases of the β→α transition temperature and hydration reactivity. However both the substitution and the presence of S were not recognized by XRD, EDX and FTIR. Increasing the amount of gypsum resulted in the formation of hydroxyapatite (Ca5(OH)(PO4)3) at 1300°C and tetracalcium phosphate (Ca4(PO4)2O) at 1400°C. The hydration reactivity was in the order, pure α-TCP << α-TCP heated with gypsum. (Received Oct. 6, 2011; Accepted March 17, 2012)
{"title":"CHARACTERIZATION AND HYDRATION REACTIVITY OF α–TRICAICIUM PHOSPHATE PREPARED BY HEATING WITH GYPSUM","authors":"H. Monma, Y. Moriyoshi, H. Ogata, T. Okura","doi":"10.3363/PRB.27.1","DOIUrl":"https://doi.org/10.3363/PRB.27.1","url":null,"abstract":"Beta tricalcium phosphate (β-Ca3(PO4)2, β-TCP) mixed with gypsum (CaSO4・2H2O) was heated at 1300°C and 1400°C. The resulting products were characterized by DTA, XRD, FTIR, EDX and hydration reactivity. An inhibition effect on the transition of the low temperature form β to high temperature form α was observed with increasing the amount of gypsum. The substitution of SO4 for PO4 was suggested from increases of the β→α transition temperature and hydration reactivity. However both the substitution and the presence of S were not recognized by XRD, EDX and FTIR. Increasing the amount of gypsum resulted in the formation of hydroxyapatite (Ca5(OH)(PO4)3) at 1300°C and tetracalcium phosphate (Ca4(PO4)2O) at 1400°C. The hydration reactivity was in the order, pure α-TCP << α-TCP heated with gypsum. (Received Oct. 6, 2011; Accepted March 17, 2012)","PeriodicalId":20022,"journal":{"name":"Phosphorus Research Bulletin","volume":"32 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74425697","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Katsuyuki Mukogawa, N. Wada, N. Horiuchi, Miho Nakamura, A. Nagai, T. Okura, K. Yamashita
: Hydroxyapatite (HAp) is the principal inorganic ingredient of human teeth and bone, and well-known as an excellent biocompatible material. HAp has been found to be polarized with an external electric field at a high temperature. Electrets are defined as the solids with functions that quasi-permanent surface charges. However, fundamental characteristics of electric fields due to HAp electrets have never been reported. Hence, this purpose is investigation of the properties of the surface electric fields of HAp bioceramic electrets; the surface potentials due to overlapping plural electrets with different electric potentials and signs; and a screening effect on electric fields with electrets due to a conductor and a dielectric. Polarized charges of the HAp electret have generated an electric field around the electret. The principle of superposition has held for the surface potentials of plural electrets. The screening effect by a conductor or a dielectric has been observed.
{"title":"SURFACE PROPERTIES OF CERAMIC HYDROXYAPATITE ELECTRETS","authors":"Katsuyuki Mukogawa, N. Wada, N. Horiuchi, Miho Nakamura, A. Nagai, T. Okura, K. Yamashita","doi":"10.3363/PRB.26.6","DOIUrl":"https://doi.org/10.3363/PRB.26.6","url":null,"abstract":": Hydroxyapatite (HAp) is the principal inorganic ingredient of human teeth and bone, and well-known as an excellent biocompatible material. HAp has been found to be polarized with an external electric field at a high temperature. Electrets are defined as the solids with functions that quasi-permanent surface charges. However, fundamental characteristics of electric fields due to HAp electrets have never been reported. Hence, this purpose is investigation of the properties of the surface electric fields of HAp bioceramic electrets; the surface potentials due to overlapping plural electrets with different electric potentials and signs; and a screening effect on electric fields with electrets due to a conductor and a dielectric. Polarized charges of the HAp electret have generated an electric field around the electret. The principle of superposition has held for the surface potentials of plural electrets. The screening effect by a conductor or a dielectric has been observed.","PeriodicalId":20022,"journal":{"name":"Phosphorus Research Bulletin","volume":"76 1","pages":"6-7"},"PeriodicalIF":0.0,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76678917","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hydrothermal, Phosphate Abstract: Spherical β-tricalcium phosphate (β-TCP) granules composed of rod-shaped particles are expected to be useful as bioresorbable bone substitutes. The β-TCP granules can be prepared by the heat treatment of Ca-deficient hydroxyapatite (HA) granules that are synthesized by hydrothermal treatment of -TCP granules. However, when the Ca/P molar ratio of Ca-deficient HA becomes higher than 1.50, depending on the hydrothermal conditions, not only the β-TCP but also the HA phase appears following heat treatment. To resolve this problem, phosphate ions were incorporated into the Ca-deficient HA granules or monetite was added to decrease the Ca/P molar ratio to less than 1.50 in the starting composition. We revealed that these processes were effective in obtaining the pure -TCP granules composed of rod-shaped particles and thus preventing
{"title":"TECHNIQUES FOR PREPARING PURE β-TRICALCIUM PHOSPHATE GRANULES COMPOSED OF ROD-SHAPED PARTICLES","authors":"M. Kamitakahara, R. Fujii, K. Ioku","doi":"10.3363/PRB.26.29","DOIUrl":"https://doi.org/10.3363/PRB.26.29","url":null,"abstract":"Hydrothermal, Phosphate Abstract: Spherical β-tricalcium phosphate (β-TCP) granules composed of rod-shaped particles are expected to be useful as bioresorbable bone substitutes. The β-TCP granules can be prepared by the heat treatment of Ca-deficient hydroxyapatite (HA) granules that are synthesized by hydrothermal treatment of -TCP granules. However, when the Ca/P molar ratio of Ca-deficient HA becomes higher than 1.50, depending on the hydrothermal conditions, not only the β-TCP but also the HA phase appears following heat treatment. To resolve this problem, phosphate ions were incorporated into the Ca-deficient HA granules or monetite was added to decrease the Ca/P molar ratio to less than 1.50 in the starting composition. We revealed that these processes were effective in obtaining the pure -TCP granules composed of rod-shaped particles and thus preventing","PeriodicalId":20022,"journal":{"name":"Phosphorus Research Bulletin","volume":"40 1","pages":"29-32"},"PeriodicalIF":0.0,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81532337","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
H. Manabe, Toshiisa Konishi, Minori Mizumoto, M. Honda, M. Aizawa
: We have developed calcium-phosphate cement (CPC) that can be formed into any desired shapes during an operation. The novel hydroxyapatite (HAp) and tricalcium phosphate (TCP) cements set on the basis of chelate-bonding ability of inositol phosphate (IP6). In the present study, we evaluated dissolution rate of various CPCs under conditions of acetic acid buffer solution at pH5.5. The concentration of calcium ions released from the CPCs with HAp, -TCP and -TCP phases in the acetic acid buffer solution was continuously measured using a calcium ion meter. The dissolution rate of samples decreased in order of -TCP > -TCP > HAp derived from wet process
{"title":"IN VITRO BIORESORBABILITY OF CHELATE-SETTING CEMENTS WITH VARIOUS CALCIUM-PHOSPHATE PHASES","authors":"H. Manabe, Toshiisa Konishi, Minori Mizumoto, M. Honda, M. Aizawa","doi":"10.3363/PRB.26.105","DOIUrl":"https://doi.org/10.3363/PRB.26.105","url":null,"abstract":": We have developed calcium-phosphate cement (CPC) that can be formed into any desired shapes during an operation. The novel hydroxyapatite (HAp) and tricalcium phosphate (TCP) cements set on the basis of chelate-bonding ability of inositol phosphate (IP6). In the present study, we evaluated dissolution rate of various CPCs under conditions of acetic acid buffer solution at pH5.5. The concentration of calcium ions released from the CPCs with HAp, -TCP and -TCP phases in the acetic acid buffer solution was continuously measured using a calcium ion meter. The dissolution rate of samples decreased in order of -TCP > -TCP > HAp derived from wet process","PeriodicalId":20022,"journal":{"name":"Phosphorus Research Bulletin","volume":"4 1","pages":"105-108"},"PeriodicalIF":0.0,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89432147","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
: The formation of strong bond between material and bone tissue, studied by Hench, Kokubo, Yamamuro, or others in 1980's is revisited to obtain some insight into apatite deposition on meso- or microporous silica gel, derived by phase separation in the system tetraethoxysilane, polyethylene glycol, and water. Testing the apatite-depositing ability on the silica gels indicated that the increase in calcium, phosphate, and hydroxyl ions in Kokubo's simulated body fluid differently affected the apatite nucleation rate, and suggested necessity of modifying the original simplistic model of apatite nucleation: calcium ion adsorption triggered nucleation. Apatite formation was reviewed on anatase layer prepared on Ti due to chemical (H 2 O 2 ) and heating treatments (CHT procedure), and balanced clustering of calcium and phosphate ions is significant for the apatite nucleation. CHT layer is proposed as a reference material for bone-bonding testing.
{"title":"BEYOND CURRENT INTERPRETATION OF BONDING BETWEEN SILICATE CERAMICS AND BONE","authors":"A. Osaka","doi":"10.3363/PRB.26.18","DOIUrl":"https://doi.org/10.3363/PRB.26.18","url":null,"abstract":": The formation of strong bond between material and bone tissue, studied by Hench, Kokubo, Yamamuro, or others in 1980's is revisited to obtain some insight into apatite deposition on meso- or microporous silica gel, derived by phase separation in the system tetraethoxysilane, polyethylene glycol, and water. Testing the apatite-depositing ability on the silica gels indicated that the increase in calcium, phosphate, and hydroxyl ions in Kokubo's simulated body fluid differently affected the apatite nucleation rate, and suggested necessity of modifying the original simplistic model of apatite nucleation: calcium ion adsorption triggered nucleation. Apatite formation was reviewed on anatase layer prepared on Ti due to chemical (H 2 O 2 ) and heating treatments (CHT procedure), and balanced clustering of calcium and phosphate ions is significant for the apatite nucleation. CHT layer is proposed as a reference material for bone-bonding testing.","PeriodicalId":20022,"journal":{"name":"Phosphorus Research Bulletin","volume":"24 1","pages":"18-22"},"PeriodicalIF":0.0,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89443627","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Takanori Watarai, Miho Nakamura, N. Horiuchi, K. Hashimoto, A. Nagai, K. Yamashita
B-type carbonate apatite (CA) substituting for phosphate ions, is the major inorganic components of vertebrate bones. CA is more biodegradable than HA and has been expected as a next generation biomaterial. We had reported that the polarized HA could promote bone healing. The purpose of this study was to investigate the effects of the electrically polarization on CA characterization. CA synthesized by wet method was sintered at various temperatures in carbon dioxide atmosphere. The TG measurement and polarization treatment of the sintered CA were performed. From the results of XRD and FT-IR analyses, CA was inclusion of contain carbonate about 5wt%. From TSDC measurement, the quantity of accumulated charges of CA was larger than HA. In addition, we evaluated the osteoclast behaviors on non-polarized CA and polarized CA. From the observation of cell morphology, there were multinucleated cells having actin ring structures specific for the activated osteoclasts on the CA surfaces. (Received May 7 2012; Accepted August 6, 2012)
{"title":"SINTERING AND OSTEOCLAST BEHAVIOR OF CARBONATE APATITE CERAMICS","authors":"Takanori Watarai, Miho Nakamura, N. Horiuchi, K. Hashimoto, A. Nagai, K. Yamashita","doi":"10.3363/PRB.27.45","DOIUrl":"https://doi.org/10.3363/PRB.27.45","url":null,"abstract":"B-type carbonate apatite (CA) substituting for phosphate ions, is the major inorganic components of vertebrate bones. CA is more biodegradable than HA and has been expected as a next generation biomaterial. We had reported that the polarized HA could promote bone healing. The purpose of this study was to investigate the effects of the electrically polarization on CA characterization. CA synthesized by wet method was sintered at various temperatures in carbon dioxide atmosphere. The TG measurement and polarization treatment of the sintered CA were performed. From the results of XRD and FT-IR analyses, CA was inclusion of contain carbonate about 5wt%. From TSDC measurement, the quantity of accumulated charges of CA was larger than HA. In addition, we evaluated the osteoclast behaviors on non-polarized CA and polarized CA. From the observation of cell morphology, there were multinucleated cells having actin ring structures specific for the activated osteoclasts on the CA surfaces. (Received May 7 2012; Accepted August 6, 2012)","PeriodicalId":20022,"journal":{"name":"Phosphorus Research Bulletin","volume":"1 1","pages":"45-49"},"PeriodicalIF":0.0,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86139859","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Sugiyama, Tomoki Hayashi, Ippei Shinomiya, Keizo Nakagawa, K. Sotowa
The elution behaviors of phosphate from the slag released by a chemical factory using various eluates were examined. Since this slag was covered with organic species, two pretreatment methods for the slag one the calcination of the slag and the other the trituration of the slag were employed to strip away the organic species from the slag. Since the elution rate from the pre-triturated slag was evidently greater than that from the pre-calcined slag, the elution behavior of the former was mainly examined in the present study. For the efficient elution of phosphate from the slag, the use of 1M HNO3 as an eluate and 30 min of trituration time were suitable. Unfortunately, together with the elution of phosphate from the slag, some cationic species were simultaneously eluted. In the present study, the removal behavior of iron cation, which was a main contaminant in the slag, using calcium hydroxyapatite (CaHAp) was also examined. Even when the solution obtained by the elution of the slag was employed for the removal of Fe using CaHAp, the Fe could be favorably removed from the solution. Results from the present study suggests that unused phosphate in slag is a potential source of raw material for rare
{"title":"RECOVERY AND ENRICHMENT OF AQUEOUS PHOSPHATE FROM THE SLAG RELEASED BY A CHEMICAL FACTORY","authors":"S. Sugiyama, Tomoki Hayashi, Ippei Shinomiya, Keizo Nakagawa, K. Sotowa","doi":"10.3363/PRB.27.23","DOIUrl":"https://doi.org/10.3363/PRB.27.23","url":null,"abstract":"The elution behaviors of phosphate from the slag released by a chemical factory using various eluates were examined. Since this slag was covered with organic species, two pretreatment methods for the slag one the calcination of the slag and the other the trituration of the slag were employed to strip away the organic species from the slag. Since the elution rate from the pre-triturated slag was evidently greater than that from the pre-calcined slag, the elution behavior of the former was mainly examined in the present study. For the efficient elution of phosphate from the slag, the use of 1M HNO3 as an eluate and 30 min of trituration time were suitable. Unfortunately, together with the elution of phosphate from the slag, some cationic species were simultaneously eluted. In the present study, the removal behavior of iron cation, which was a main contaminant in the slag, using calcium hydroxyapatite (CaHAp) was also examined. Even when the solution obtained by the elution of the slag was employed for the removal of Fe using CaHAp, the Fe could be favorably removed from the solution. Results from the present study suggests that unused phosphate in slag is a potential source of raw material for rare","PeriodicalId":20022,"journal":{"name":"Phosphorus Research Bulletin","volume":"389 1","pages":"23-27"},"PeriodicalIF":0.0,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79716739","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The aim of this work is to develop a highly-functional tissue engineering scaffold from silicon-containing apatite fibres (Si-AF). Firstly, Si-AFs were synthesized by a homogeneous precipitation method. Starting solution with a Ca/(P+Si) ratio of 1.67 was prepared by mixing Ca(NO3)24H2O, (NH4)2HPO4, Si(OC2H5)4 (TEOS), (NH2)2CO and HNO3. The concentrations of TEOS in the starting solution were 0 (AF), 0.8 (0.8Si-AF) and 1.6 (1.6Si-AF) mass%. Next, Si-AF scaffolds (Si-AFS) were fabricated by firing the compacts consisting of Si-AF and carbon beads of 150 m diameter. The resulting Si-AFSs were characterized using X-ray diffractometry (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and inductively coupled plasma atomic emission spectrometry (ICP-AES). Results showed that the material properties of the 0.8Si-AFS were similar to those of the conventional AFS without silicon. Consequently, we can conclude that the 0.8Si-AFS offers as a potential novel scaffold material, creating a three-dimensional cell culture environment. (Received March 29, 2012; Accepted April 9, 2012)
这项工作的目的是从含硅磷灰石纤维(Si-AF)中开发一种高功能的组织工程支架。首先，采用均匀沉淀法合成了Si-AFs。将Ca(NO3)2、(NH4)2HPO4、Si(OC2H5)4 (TEOS)、(NH2)2CO和HNO3混合，制得Ca/(P+Si)比为1.67的起始溶液。起始溶液中TEOS的浓度分别为0 (AF)、0.8 (0.8 si -AF)和1.6 (1.6 si -AF)质量%。接下来，通过烧制由Si-AF和直径为150m的碳珠组成的致密物，制备Si-AF支架(Si-AFS)。采用x射线衍射(XRD)、傅里叶变换红外光谱(FT-IR)、扫描电镜(SEM)和电感耦合等离子体原子发射光谱(ICP-AES)对所得的Si-AFSs进行了表征。结果表明，0.8Si-AFS的材料性能与常规无硅AFS相似。因此，我们可以得出结论，0.8Si-AFS作为一种潜在的新型支架材料，可以创建三维细胞培养环境。(2012年3月29日收稿;2012年4月9日接受)
{"title":"FABRICATION AND EVALUATION OF SILICON-CONTAINING APATITE FIBER SCAFFOLDS FOR BONE TISSUE ENGINEERING","authors":"Y. Kinoshita, S. Best, M. Aizawa","doi":"10.3363/PRB.26.101","DOIUrl":"https://doi.org/10.3363/PRB.26.101","url":null,"abstract":"The aim of this work is to develop a highly-functional tissue engineering scaffold from silicon-containing apatite fibres (Si-AF). Firstly, Si-AFs were synthesized by a homogeneous precipitation method. Starting solution with a Ca/(P+Si) ratio of 1.67 was prepared by mixing Ca(NO3)24H2O, (NH4)2HPO4, Si(OC2H5)4 (TEOS), (NH2)2CO and HNO3. The concentrations of TEOS in the starting solution were 0 (AF), 0.8 (0.8Si-AF) and 1.6 (1.6Si-AF) mass%. Next, Si-AF scaffolds (Si-AFS) were fabricated by firing the compacts consisting of Si-AF and carbon beads of 150 m diameter. The resulting Si-AFSs were characterized using X-ray diffractometry (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and inductively coupled plasma atomic emission spectrometry (ICP-AES). Results showed that the material properties of the 0.8Si-AFS were similar to those of the conventional AFS without silicon. Consequently, we can conclude that the 0.8Si-AFS offers as a potential novel scaffold material, creating a three-dimensional cell culture environment. (Received March 29, 2012; Accepted April 9, 2012)","PeriodicalId":20022,"journal":{"name":"Phosphorus Research Bulletin","volume":"3 1","pages":"101-104"},"PeriodicalIF":0.0,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75199810","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Calcium phosphate glasses and glass-ceramics with some limited compositions show bioactivity. The glasses could be prepared by including a small amount of TiO2 and/or Na2O: the typical compositions were 60CaO-30P2O5-xTiO2-(10‒ x)Na2O in mol%. The glasses include orthophosphate and pyrophosphate groups. Hydroxyapatite (HA) forming ability in a simulated body fluid (SBF) is often examined to know the chemical properties of materials for biomedical applications. On the 60CaO-30P2O5-xTiO2-(10‒x)Na2O glasses, HA formed within 7-10 days. In the case of the glasses, the HA-forming ability is suggested to be influenced by various factors such as the basicity of a gel layer formed on them in SBF and the amount of the functional groups for HA nucleation in the layer. Modification of the glass composition, which MgO was substituted to CaO, improved the glassification tendency of the glasses due to the high field strength of Mg. The MgO-containing glass included a larger amount of orthophosphate group than the original glass, and showed higher ion-releasing ability. Bivalent ions in the phosphate invert glasses play an important role in their glassification and ion-releasing. The glasses were crystallized and subsequently sintered by heating their powder-compacts. The resulting glass-ceramics consist of -Ca3(PO4)2 and -Ca2P2O7 with residual glassy phase. Their HA-forming ability in SBF was enhanced after autoclaving in distilled water. By the autoclaving, sodium, calcium, phosphate ions in the glassy phase around the surface dissolved and anatase crystals formed. The glass-ceramics could be coated strongly on a new -type titanium alloy using a conventional glazing technique. The glass-ceramic-coated materials were implanted into the femurs of Japanese rabbits. After 1 month, bone tissue contacted directly with the coating. After 5 years of implantation, the coating was clarified to be work as a bioactive material on the titanium alloy. (Received January 27, 2012; Accepted February 16, 2012)
{"title":"PHOSPHATE GLASSES AND GLASS-CERAMICS FOR BIOMEDICAL APPLICATIONS","authors":"T. Kasuga, T. Hattori, M. Niinomi","doi":"10.3363/PRB.26.8","DOIUrl":"https://doi.org/10.3363/PRB.26.8","url":null,"abstract":"Calcium phosphate glasses and glass-ceramics with some limited compositions show bioactivity. The glasses could be prepared by including a small amount of TiO2 and/or Na2O: the typical compositions were 60CaO-30P2O5-xTiO2-(10‒ x)Na2O in mol%. The glasses include orthophosphate and pyrophosphate groups. Hydroxyapatite (HA) forming ability in a simulated body fluid (SBF) is often examined to know the chemical properties of materials for biomedical applications. On the 60CaO-30P2O5-xTiO2-(10‒x)Na2O glasses, HA formed within 7-10 days. In the case of the glasses, the HA-forming ability is suggested to be influenced by various factors such as the basicity of a gel layer formed on them in SBF and the amount of the functional groups for HA nucleation in the layer. Modification of the glass composition, which MgO was substituted to CaO, improved the glassification tendency of the glasses due to the high field strength of Mg. The MgO-containing glass included a larger amount of orthophosphate group than the original glass, and showed higher ion-releasing ability. Bivalent ions in the phosphate invert glasses play an important role in their glassification and ion-releasing. The glasses were crystallized and subsequently sintered by heating their powder-compacts. The resulting glass-ceramics consist of -Ca3(PO4)2 and -Ca2P2O7 with residual glassy phase. Their HA-forming ability in SBF was enhanced after autoclaving in distilled water. By the autoclaving, sodium, calcium, phosphate ions in the glassy phase around the surface dissolved and anatase crystals formed. The glass-ceramics could be coated strongly on a new -type titanium alloy using a conventional glazing technique. The glass-ceramic-coated materials were implanted into the femurs of Japanese rabbits. After 1 month, bone tissue contacted directly with the coating. After 5 years of implantation, the coating was clarified to be work as a bioactive material on the titanium alloy. (Received January 27, 2012; Accepted February 16, 2012)","PeriodicalId":20022,"journal":{"name":"Phosphorus Research Bulletin","volume":"33 1","pages":"8-15"},"PeriodicalIF":0.0,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75206899","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Y. Asano, Y. Sakka, J. DaviesIan, S. Koda, K. Itatani
The effect of -calcium orthophosphate (-Ca3(PO4)2:-TCP) addition (1 ~ 20 mass%) on the high-temperature plastic deformation of hydroxyapatite (Ca10(PO4)6(OH)2:HAp) ceramic specimen was examined. The high-density HAp ceramic body with -TCP addition, which was composed of submicrometer-sized grains, was fabricated by pulse-current pressure firing at a temperature between 900 and 1050C for 10 min under a pressure of 50 MPa. The relative densities of HAp ceramics with 1 to 20 mass% -TCP addition fabricated by pulse-current pressure firing at 1000C for 10 min exceeded 99%; the grain sizes increased from 0.2 to 0.3 m with increasing -TCP addition from 0 to 10 mass% and then steeply to 0.9 m with increasing -TCP addition from 10 to 20 mass%. The tensile strain of the HAp specimen with 1 mass% -TCP addition pulse-current pressure fired at 1000C for 10 min achieved a maximum of 390% for a test temperature of 1000C and a strain rate of 1.48 10 -4 s -1 , compared to 364% for the monolithic HAp specimen.
{"title":"EFFECT OF β-CALCIUM ORTHOPHOSPHATE ADDITION ON HIGH- TEMPERATURE PLASTIC DEFORMATION OF HYDROXYAPATITE WITH SUBMICROMETER-SIZED GRAINS","authors":"Y. Asano, Y. Sakka, J. DaviesIan, S. Koda, K. Itatani","doi":"10.3363/PRB.27.11","DOIUrl":"https://doi.org/10.3363/PRB.27.11","url":null,"abstract":"The effect of -calcium orthophosphate (-Ca3(PO4)2:-TCP) addition (1 ~ 20 mass%) on the high-temperature plastic deformation of hydroxyapatite (Ca10(PO4)6(OH)2:HAp) ceramic specimen was examined. The high-density HAp ceramic body with -TCP addition, which was composed of submicrometer-sized grains, was fabricated by pulse-current pressure firing at a temperature between 900 and 1050C for 10 min under a pressure of 50 MPa. The relative densities of HAp ceramics with 1 to 20 mass% -TCP addition fabricated by pulse-current pressure firing at 1000C for 10 min exceeded 99%; the grain sizes increased from 0.2 to 0.3 m with increasing -TCP addition from 0 to 10 mass% and then steeply to 0.9 m with increasing -TCP addition from 10 to 20 mass%. The tensile strain of the HAp specimen with 1 mass% -TCP addition pulse-current pressure fired at 1000C for 10 min achieved a maximum of 390% for a test temperature of 1000C and a strain rate of 1.48 10 -4 s -1 , compared to 364% for the monolithic HAp specimen.","PeriodicalId":20022,"journal":{"name":"Phosphorus Research Bulletin","volume":"144 1","pages":"11-17"},"PeriodicalIF":0.0,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89029251","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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