bluuebunny/crossref_metadata_2025 huggingface dataset:
High Performance SiC Fibers from Polycarbosilane for High Temperature Applications
Authors: Ichikawa Hiroshi
Published: March 2009

In recent years, it has been increasing in demand for high performance CMCs for high
temperature application. CMCs are most promising materials for high temperature structural
materials of gas turbines for aerospace and power generation. Mechanical performances of CMCs
are highly dependent on properties of the reinforcement.
The oxygen free SiC fiber (Hi-Nicalon) has been commercially produced by an electron beam
curing process. And then the SiC fiber (Hi-Nicalon Type S) having stoichiometric SiC composition
and high crystallinity was developed. Hi-Nicalon fiber has higher elastic modulus and thermal
stability than Nicalon fiber. The Type S fiber has the highest elastic modulus and thermal stability
and excellent creep resistance in three types of Nicalon family fibers.
Recently, the Type S fibers as industrial products were developed and put on the market. The
Type S (industrial version) fibers had a high tensile strength of 2.8 GPa, a high elastic modulus of
390 GPa. The Type S fiber retained a tensile strength of 2.2 GPa and an elastic modulus of 390 GPa
after exposure at 1873 K. Moreover, the Type S fiber had outstanding creep resistance; the Type S
fiber showed higher stress relaxation ratio than many other ceramic fibers after thermal exposure
over 1673 K. The Type S fibers could be the best candidate for the reinforcement of CMCs. The
fibers can be supplied about 30 kg per a month at present.
Now, the Type S fiber/BN/SiC composites are being developed as the components of gas turbine
for aerospace and land based power generation such as shrouds and combustors.
Atomic-Scale Structure of Polymer-Route Si-C-O Fibers Observed by Synchrotron Radiation X-Ray Diffraction
Authors: Okamura Kiyohito , Suzuya Kentaro , Kohara Shinji , Ichikawa Hiroshi , Suzuki Kenji
Published: March 2009

The atomic scale structure of amorphous Si-C-O ceramics fibers produced from the pyrolysis of a polycarbosilane precursor has been investigated by X-ray diffraction using high-energy synchrotron radiation at SPring-8. First peak in the total correlation function T(r) of the amorphous and the heat-treated fibers is analyzed to consist of two contributions: Si-C (1.89 Å) and Si-O (1.61 Å) bonds. The coordination number of C and/or O around Si is about four. This suggests that the Si-C-O fibers basically have a network structure that consists of two tetrahedral units: SiC4 and SiO4. The local chemical and structural orders vary continuously in the materials from the disordered network structure of SiC4 and SiO4 tetrahedra (mixture of amorphous SiC and SiO2) to nanocrystals of SiC and SiO2, through the ternary Si-C-O solid solution which is believed to have an intermediate structure between the amorphous and crystalline states.
Deflocculation of Alumina Suspensions Using Polyelectrolyte Dispersants
Authors: Liu Yang Qiao , Gao Lian
Published: March 2009

In this paper, the dispersing abilities of three polyelectrolytes, poly (acrylic acid), poly
(acrylic acid-co-acrylate), and a four-member copolymer containing various anionic functional
groups were tested for aqueous Al2O3 suspensions. The influence of the dispersants on the surface
charge of the powder was evaluated by measuring the zeta potential in dilute Al2O3 suspensions. It
was found that all the three dispersants shifted the isoelectric point to a lower pH value. Rheological
measurements showed that the four-member dispersant decreased the viscosity in the widest pH
range, which should be ascribed to the synergistic effect of different functional groups. The 58vol%
concentrated Al2O3 slurry using the four-member dispersant was further consolidated using gel
casting and was fully sintered at 1600oC.
Generalized Thermoelastic Responses of a Piezoelectric Rod Subjected to a Moving Heat Source
Authors: He Tian Hu , Cao Li
Published: March 2009

Based on the Lord and Shulman generalized thermo-elastic theory, the dynamic thermal
and elastic responses of a piezoelectric rod fixed at both ends and subjected to a moving heat source
are investigated. The generalized piezoelectric-thermoelastic coupled governing equations are
formulated. By means of Laplace transformation and numerical Laplace inversion the governing
equations are solved. Numerical calculation for stress, displacement and temperature within the rod
is carried out and displayed graphically. The effect of moving heat source speed on temperature,
stress and temperature is studied. It is found from the distributions that the temperature, thermally
induced displacement and stress of the rod are found to decrease at large source speed.
The Effects of Energy Director Shape on Temperature Field during Ultrasonic Welding of Thermoplastic Composites
Authors: Yan Jiu Chun , Wang Xiao Lin , Li Rui Qi , Xu Hui Bin , Yang Shi Qin
Published: March 2009

The ultrasonic welding process of thermoplastic composite with different shapes of energy
director (ED) was simulated using finite element model. The results show that the highest temperature
zone locates at the tip for the semicircular and triangular ones, and locates at the middle height for the
trapezoid one. But it does not locate at the body of ED for the rectangular one. Energy director with
different shapes lead to the temperature rising rate at different order of amplitude. The welding
amplitude has same influence on the four shapes of ED. The temperature distributing profiles of
semicircular, triangular and trapezoid ED keep constant from the initial welding time to that when the
highest temperature on joints arrives the temperature of glass transformation (Tg), but the profile for
rectangular ED changes greatly.
A Thermal Damage Model of UHMWPE
Authors: Gao Xin Lei , Li Jian , Gao Wan Zhen , Qin Xiang Pei
Published: March 2009

Ultra high molecular weight polyethylene (UHMWPE) is a kind of non-polar polymer
with a crystalline structure. Its failure appeared usually as a type of wire drawing when it was used
as a material of rubbing pairs. By a designed heating test, the thermal damage phenomena of
UHMWPE were observed by SEM. Its thermal damage model during the process of wire drawing
damage was assumed that when the thermal energy was accepted by the UHMWPE, its volume
expanding and its surface melting into a viscous fluid proceeded from its elevated temperature, and
then the viscous fluid flowed according with non-Newtonian fluid model; after cooling, the melt
re-crystallized and gathered again and at the same time many obvious cavities with phenomena of
wire drawing appeared in the re- crystalline polymer. As a result the material of UHMWPE shrank
to porosint from the congeries with the small uniform particles.
Experimental Investigation on Effects of Depth of Cut on Micro-Geometric Properties in Quick-Point Grinding
Authors: Xiu Shi Chao , Li Chang He , Cai Guang Qi
Published: March 2009

Quick-point grinding is used to machine the round surface with super abrasive wheel at
high grinding speed. Because it is point contact between the grinding wheel and the workpiece due
to the point grinding angles in the process, the grinding model is different from the conventional
cylindrical grinding in theory. Especially, the edge contact width between the wheel and the
workpiece is not always equal to the thickness of the wheel, but rests with the depth of cut and the
grinding angles greatly. The depth of cut has the effects on the micro-geometric properties
especially the ground surface roughness by means of the variations of the edge contact width, the
grinding force and heat in the process. Based on the theoretical studies on the surface roughness, the
quick-point grinding experiments and the measures for the surface roughness were performed at
different depth of cut. The effective mechanism of the depth of cut on the ground surface roughness
was analyzed deeply. Some conclusions to influence surface roughness were also gained.
Interpretative Structural Modeling for Ceramic Grindability System
Authors: Yu Ai Bing , Zhao Nan , Wang Yan Lin , Tian Xin Li
Published: March 2009

Based on systematic engineering theory and method, interpretative structural model of
ceramic grindability system was set up. Property parameters, grinding parameters and grindability
indexes were selected as system elements. The adjacency matrix between system elements was
constructed. The reachability matrix was calculated according to adjacency matrix. By calculation
of reachability matrix and classification, interpretative structural model of the ceramic grindability
system was obtained. The system model could describe the relationship between the ceramic
grindability and system elements. The grindability system model also provides a fundamental
theoretical reference for the research on the grindability of ceramic materials. The weight of each
influencing factor of ceramic grindability can be calculated by applying the system model. The
grindability of ceramic materials can be evaluated objectively and comprehensively.
Experiment Study on Residual Stresses Based on Quick-Point Grinding with Vitrified CBN Wheel
Authors: Pang Zi Rui , Yuan Suo Xian , Wang Wan Shan , Zhu Chun Xia
Published: March 2009

In this paper, we emphasize that residual stresses in a ground surface are primarily
generated due to grinding zone temperature effect, and discuss grinding zone temperature can be
debased based on characteristics of the thin vitrified bond CBN wheel and quick-point grinding. Via
experimental results of 5 group working procedures, we find that surface roughness Ra showed a
tendency to reduce slightly with infeed rate reduced, cut depth increased, grinding wheel speed and
grinding variable angle increased, the favorable residual compressive stress could obtained along
with variables angle(α, β) increased, the sub-surface white etching layer and tempered martensite
layer in size become thinner with α, β angle and grinding wheel speed increased when removal rate
Z=0.06mm3/mm keep constant in quick-point grinding, by contraries, surface quality were
decreased entirely when variables angle(α, β) equal to zero. The results indicate it is important that
grinding variable angle were choice in quick-point grinding for to obtain favorable residual
compressive stress.
Crown Modification of Cylinder-Roller Bearing Raceway Using Electrochemical Abrasive Belt Grinding
Authors: Xu Wen Ji , Tao Bin , Pang Gui Bing , Wang Xu Yue , Zhao Xiao Hui
Published: March 2009

This paper researches on the theory of the crown modification of cylinder-roller bearing
raceway using electrochemical abrasive belt grinding (ECABG) technology, and establishes relevant
experimental device. The range of processing parameters with a better surface roughness can be
obtained through experiments. On this basis, a mathematics model of distribution of material
removal of electrochemical machining bearing is set up. Considering the controllability of
processing parameters and demand of the surface quality, the processing parameters such as
interelectrode voltage, electrolyte, interelectrode gap and cathode geometry are invariable in the
experiment, and processing time is changed to control the crown value. The experimental results
show that ECABG can enhance the surface quality of raceway to a great degree, and obtain the ideal
forming crown at the same time under the optimum technological parameters. This paper developed a
new method for the crown processing and finishing of bearing raceway.
Research on Cryogenic Pneumatic Mist Jet Impinging Cooling and Lubricating of Grinding Processes
Authors: An Qing Long , Fu Yu Can , Xu Jiu Hua
Published: March 2009

Grinding, characterized by its high specific energy consumption, may generate high grinding zone temperature. These can cause thermal damage to the ground surface and poor surface integrity, especially in the grinding of difficult-to-machine materials. Conventional cooling methods based on large amounts of water-oil emulsions can be both ineffective and environmentally unacceptable. Here a new high efficiency cooling technology—cryogenic pneumatic mist jet impinging cooling technology is offered. It utilizes the high penetrative power of fast cryogenic air jet combined with a little quantity of 0°C water to greatly improve heat transfer effects in the machining zone. The experimental results indicated that CPMJI could offer better machining effects compared to cold air jet and traditional flood cooling method in the grinding of titanium alloy.
Evaluation and Measurement of 3D Form Errors of Ground Curve Surface
Authors: Xie Jin , Guo Jia Long , Xu Jing
Published: March 2009

Evaluation and measurement of form errors distributed on 3D ground curved surface are
proposed due to the difficulty of processing measured points of 3D ground curve surface in
comparison with axisymmetric curved surface. First form curved surface grinding is conducted by
arc-shaped diamond grinding wheel, second ground curved surface is measured by contact
measurement to obtain 3D measuring data, next transfer mode from CNC grinding to measuring
reference frames is established, then effective and applicable 3D compensation arithmetic for probe
sphere error is introduced, finally 3D form errors are investigated in connection with reference frame
transfer and probe sphere compensation. It is confirmed that form error PV of is improved form 203 m
/ 8 cm2 is obtained by using reference frame transfer and probe sphere compensation, enhancing
measuring accuracy by about 29 %.
Development of the 6-Axles CNC Abrasive Belt Grinding Machine
Authors: Huang Zhi , Huang Yun , Zhang Ming De , Guo Xiao Dong
Published: March 2009

This paper describes the conventional machining method on turbine blade, brings
forward a reasonable method which can polishing free-form surface with abrasive belt grinding
technology by CNC, expatiates this new grinding machine structure design and CAM software key
techniques , finally summarizes this new grinding techniques and machine.
Mechanical Behaviors of Metal-Bonded Diamond Abrasive Tools with Different Grit Sizes
Authors: Yu Yi Qing , Tie Xiao Rui , Xu Xi Peng
Published: March 2009

The present study was undertaken to compare the hardness and transverse rupture strength
(TRS) of metal-based tooling composites containing diamonds of different grit sizes. Two kinds of
bond matrix, copper-based and iron-based, were applied in the fabrication of the composites. In the
copper-based matrix, rare earth was used as an additive. Diamonds of three different grit sizes were
incorporated into two bond matrix, thereby forming six kinds of diamond composites. SEM and EDS
were used to analyze the fractured surfaces of the composites. It was found that the diamonds of
medium grit size in the copper-based bond matrix led to the highest hardness and TRS. For the
iron-based bond matrix, however, the hardness and TRS of the composites containing the coarsest
diamonds were found to be the highest. In same bond matrix, a close relationship between TRS and
hardness was established.
Comparison of HAp and β-TCP in BMP-2 Dose-Response and Release Study
Authors: Tazaki Junichi , Akazawa Toshiyuki , Murata Masaru , Yamamoto Masaya , Tabata Yasuhiko , Hino J. , Arisue Makoto , Shibata Takanori
Published: March 2009

The aim of this study is to investigate in vivo local BMP-2 PK and bone induction in two bioceramics blocks (HAp, β-TCP), based on different composition and surface structures. We estimated the in vivo release profile of 125I–labeled BMP-2 and bone induction of hard tissues histologically. β-TCP is more effective for both BMP-2 retention and bone induction, compared to HAp, in the ectopic model.
The Influence of Titanium Particles Size on Bone Marrow Mensenchymal Stem Cells Viability
Authors: Wu Jiang , Yin Guang Fu , Chen Huai Qing , Sung K.L. Paul
Published: March 2009

The decrease in bone mass caused by wear debris-induced osteolysis could have been
compensated through osteoblasts secreting enough new bone matrix. However, the normal
osteoblastic population depends on the regular differentiation of their progenitor cells, the bone
marrow mesenchymal stem cells (BMSCs). It is not possible to predict whether wear particles will
affect the BMSCs’ viability, and subsequently their differentiation. Furthermore, little is known about
the extent to which the sizes of the wear particles loading can impact the viability the most. This study
has, therefore, concentrated on the potential mechanism for rat BMSCs’ (rBMSCs) viability
influenced by different-sized titanium particle (Ti) loading in vitro.rBMSCs were harvested and
loaded with circular Ti particles having three different mean diameters, 0.9, 2.7 and 6.9 .m
respectively. The results showed that different-sized titanium particles all inhibited rBMSCs’
proliferation and induced rBMSCs’ apoptosis response , but this influence varied with the size of the
Ti particles, their concentration and the duration of loading. The smallest Ti particles (0.9.m)
exhibited the earliest and largest suppression on the proliferation and the most powerful induction on
the apoptotic response of rBMSCs. qRT-PCR analysis demonstrated that those apoptotic effects were
association with the abnormal accentuation of inducible nitric oxide synthase(iNOS) activity. The
size of titanium particles generated through wear of a prosthetic device and the osteoblastic progenitor
BMSCs may be both important considerations in the development of superior implant technology.
Comparative Study of Ceramics Structure for Culturing Human Mesenchymal Stromal Cells
Authors: Matsushima Asako , Kotobuki Noriko , Tadokoro Mika , Ohgushi Hajime
Published: March 2009

Hydroxyapatite (HA) ceramics together with various kinds of osteogenic cells have been used in bone tissue engineering. It is well known that the ceramics structure and composition affect cell proliferation / differentiation. In this study, three different types of HA ceramics were used to investigate initial cell attachment followed by osteoblastic differentiation of human mesenchymal stromal cells (MSCs). The results indicated that micro-pore affected the cell attachment and porosity (pore diameter and inter-pore connection) was the key to allow spacious distribution of the viable cells in the ceramics. This study also confirmed that surface pore areas of HA ceramics support the differentiation of human MSCs and thus the ceramics have the capability to regenerate damaged bone tissue.
Biological and Biomechanical Behavior of Titanium Implants with Fluoridated Hydroxyapatite Coatings
Authors: Wang Xiang Hua , Yan Wei Qi , Shu Wu Bing , Luo Xiao Ting , Zhang Sam
Published: March 2009

For dental/orthopedic implants to achieve better bone apposition and bone-implant
bonding, various approaches to improve titanium surfaces have been developed. Recently, a
fluoridated hydroxyapatite (FHA) coating on titanium (Ti) implants was made by sol–gel method
and shown to be a possible applicative bone implant. The purpose of the current study was to
evaluate biological responses and biomechanical bonding strength of FHA coated Ti implants as
compared with that of the conventional Ti alloys and hydroxyapatite (HA) coated Ti implants. In
vitro assays were made using human osteoblast-like cell (MG63) culture on different implants with
cell attachment, morphology and differentiation evaluations. The implant plates were also
implanted into the proximal metaphysis of New Zealand White rabbit tibiae. After 8 and 16 weeks
implantation, mechanical and histological assessments were performed to evaluate biomechanical
and biological behavior in vivo. The results showed that the cell adhesion and cell growth rate on
the FHA and HA surface was higher than that on cp Ti surface (p<0.01), and insignificant
difference was observed between two coated groups. Mechanical test demonstrated that the FHA
implants had a higher interface shear strength than the both controls at 8 and 16 wks, with no
significant difference with HA-Ti. Histologically, the coated implants revealed a significantly
greater percentage of bone-implant contact when compared with the uncoated implants. Results
demonstrated that the new FHA surface improved cell adhesion and proliferation. The coating
exhibited a bioactive mechanical and histological behavior at bone-implant interface, suggesting
that a useful approach by combined coating processes could optimize implant surfaces for bone
deposition and early implant fixation.
In Vitro and In Vivo Biological Behavior of CDHA/OCP/β-TCP Scaffold
Authors: Minarelli Gaspar Ana Maria , Saska Sybele , Jimenez J. , da Cunha L.R. , Bolini P.D.A. , Leal Claudinete V. , Morejón-Alonso L. , García Carrodeguas R. , López-Bravo A. , Zavaglia Cecília A.C.
Published: March 2009

The biological behavior of a new bioactive material composed of calcium-deficient
hydroxyapatite, octacalcium phosphate, and β-tricalcium phosphate was investigated by in vitro
indirect and direct cytotoxicity, cell adhesion and proliferation tests, and by in vivo subcutaneous
and bone implantation in rats. The results of the in vitro studies showed that the material is
biocompatible and no cytotoxic. Slightly poorer initial cell adhesion and lower cell proliferation
than in control was observed, which were attributed to the reactivity and roughness of the material
surface. In vivo results showed that the material is biodegradable and bioactive in bone tissue, but
only biocompatible and partially biodegradable in soft tissue.
Effect of Sintering Process of HA/TCP Bioceramics on Microstructure, Dissolution, Cell Proliferation and Bone Ingrowth
Authors: Daculsi G. , LeGeros Racquel Z. , Grimandi Gael , Soueidan A. , Aguado Eric , Goyenvalle Eric , LeGeros John P.
Published: March 2009

The purpose of this study was to determine the effect of sintering conditions on microporosity of and cell proliferation and bone ingrowth on biphasic calcium phosphate (BCP) bioceramics. Discs were prepared from a calcium-deficient apatite preparation that upon sintering at 1050oC and above, results in a BCP with 60% hydroxyapatite (HA)/ 40% beta-tricalcium phosphate (β-TCP) ratio. The discs were divided into groups which were sintered under different conditions of heating rate (programmed vs. non-programmed) and temperature (1050°C vs. 1200°C). The discs were characterized in terms of composition (HA/β-TCP ratio), surface morphology, surface area, surface microporosity, per cent microporosity, and dissolution properties. The in vitro effect of sintering conditions on cell proliferation was determined using an established mouse fibroblast cell line (L929). Results demonstrated the following: (a) the HA/β-TCP ratio remained 60/40 regardless of sintering conditions; (b) the % microporosity, surface microporosity, surface area of the BCP and cell proliferation on the BCP significantly decreased with increasing sintering temperature, and (c) the extent of dissolution decreased with decreasing per cent microporosity. The in vivo study indicated no tissue adverse reaction and direct bone contact with the implant surface, confirming the biocompatibility of the BCP bioceramics. Resorption of the BCP and bone ingrowth was directly related to the sintering temperature: the higher the temperature, the lower the resorption and the bone ingrowth. Results of this study indicate that per cent microporosity of the BCP bioceramics affects its dissolution properties and cell response. The study demonstrates that optimum per cent microporosity elicits optimum cell response and should be considered to provide osteogenic/osteoinductive property to bioceramics.
Osteogenic Influence of Lysine in Porous Hydroxyapatite Scaffold
Authors: Tsuji N. , Yoshikawa Masataka , Shimomura Y. , Yabuuchi T. , Hayashi H. , Ohgushi Hajime
Published: March 2009

The purpose of this study was to estimate influence of lysine for osteogenesis in the
porous hydroxyapatite (HA) scaffolds with bone marrow cells. The HA scaffolds were soaked in
100mM concentration of lysine solution. They were kept in bone marrow cell suspension at 1×106
cells/ml density. Another HA scaffolds without immersion in lysine solution were kept in the cell
suspension at 1×106 or 1×107 cells/ml density. They were respectively implanted into dorsal
subcutis of rats for 4 weeks. Serially sectioned paraffin specimens were made and observed
histologically. In several sections, total pores and ones with bone were counted. Many pores
containing bone were found in1×107 cells/ml concentration group. The significant difference was
between 1×107 cells/ml group, the lysine group, and 1×106 cells/ml group. Although more bone
formation was seen in lysine group than in 1×106 cells/ml group. There was no significant
difference between the groups. Concentration of lysine to add in culture medium or scaffold should
be improved respectively.
Histological Evaluation of a New Biomaterial Releasing Magnetite Nanoparticles inside Bone Metastases for Thermotherapy
Authors: Frayssinet Patrick , Combacau Marylène , Gougeon Michel , Rouquet Nicole
Published: March 2009

Magnetite nanoparticles were used for their ability to be heated when they are put in an
oscillating magnetic field. When they are located inside tumors they can eradicate the tumor cells
by heating. We have developed a biomaterial constituted by a mineral degradable matrix containing
magnetite nanoparticles. This material can be injected into bone metastasis in which it sets and
releases magnetite particles uptaked inside the cancer cells. We have implanted this material inside
rabbit bone to check by histology the fate of the nanoparticles in bone. The implant matrix was
degraded within a few days releasing the nanoparticles. They were found inside monocytes and
fibroblasts having ingrown the material. The nanoparticles could form aggregates which then were
fragmented in micro/nanoparticles penetrating the surrounding cells. This study showed that the
nanoparticles are released from the mineral matrix within a few days and penetrate the cells in their
close proximity.
Controlled Drug Release Using Nanoporous Alumina Capsules
Authors: Li Li , Zhou Zhou Zheng , Li Zhen , Wu CH.X.
Published: March 2009

Nano-materials and technology increasingly come under emphasis on application in biomedical treatment and pharmaceutical field. Drug particle with nano-size has better bioactivity and absorptivity, which advance the efficiency of utilization. The nanoporous alumina membranes fabricated by anodization are provided with orderd nanoporous structure, highly uniform pore size, straight and parallel pore channels, moreover, this material possesses favorable biocompatibility. Recently, application of nanoporous alumina membranes in medical science has becoming public concerned in present biomedical material field. Our experiment aimed at fabricating nanoporous alumina membranes with definite mechanical strength to cylindrical biofiltration capsules, which can be used to encapsulate nanodrug to control drug delivery. The release characteristic was examined by monitoring the diffusion of fluorescein isothocyanate (FITC) with molecular weight of 389.4Da as a function of time after encapsulation within the alumina tubes.
Clinical Experiences of Ceramic Total Knee Arthroplasty More than 26 Years
Authors: Oonishi Hironobu , Kim Sok Chol , Oonishi Jr. Hiroyuki , Kyomoto Masayuki , Iwamoto Mikio , Ueno Masaru , Ohashi Hirotsugu
Published: March 2009

In the late 1970s, we started the clinical use of total knee prostheses (TKPs) composed of
alumina ceramic. In this study, we investigated the long-term clinical performance of ceramic TKPs.
First-generation ceramic TKPs were used between 1981 and 1985; second-generation TKPs, between
1990 and 1996 and third-generation TKPs, between 1993 and 1998. We examined the findings of
clinical radiographic observation. A total of 137 first-generation ceramic TKPs were followed up for
20–23 years after implantation. All the rates of loosening, sinking and revision were higher with
cementless fixation than with cemented fixation. In the second- and third-generation TKPs, all the
components were implanted using bone cement. In 249 joints that were followed up for 6–14 years,
neither loosening nor sinking was observed. No osteolysis was observed in any case. We compared
the wear of metal TKPs and ceramic TKPs that were retrieved after long-term use. Metal TKPs
exhibited a higher wear rate than ceramic TKPs, and they also exhibited scratched surface damages.
The lower wear rate and considerably less surface damage observed in our previous study suggest the
long-term durability and performance of ceramic TKPs.
Nineteen Years Review of Hydroxyapatite Ceramic Coated Hip Implants: A Clinical and Histological Evaluation
Authors: Buchanan James M. , Goodfellow Sally
Published: March 2009

The goal of hip arthroplasty is to restore the patient to an active and pain free life for ever. Unfortunately, prosthetic implants fail because of loosening, wear or infection. This study sets out to ascertain whether or not Hydroxyapatite hip arthroplasty (HA) will produce long-lasting function of at least ten years in unselected patients of all ages and all diagnoses. Cemented implants used in hip arthroplasty often loosen after ten or more years of use. This is partly mechanical but also associated with debris disease arising from plastic wear products. Cementing techniques have been improved and the Swedish Hip Register [1] demonstrates that the revision rates have been reduced with improved cementing techniques. Revision surgery after cemented arthroplasty is difficult and may be complicated by fracture of the host bone Bioactive materials are being used to secure joint implants [2,3] and this paper presents the results of a consecutive series of hip arthroplasties carried out over a total period of over 19 years using the Furlong Hydroxyapatite Ceramic Coated hip prosthesis.[4, 5]
TricOsTM and Fibrin Sealant Combined for Bone Defect Filling: from Pre-Clinical Tests to Prospective Clinical Study. Preliminary Human Data
Authors: Durand Marlene , Chauveaux Dominique , Moinard Maryse , Fabre Thierry , Rouvillain Jean Louis , Bagot d'Arc Maurice , Daculsi G.
Published: March 2009

The association of TricOsTM (Macroporous Biphasic Ceramic Phosphate MBCP
granules) and the fibrin sealant FS VH S/D 4, has been developed to answer a challenging request
of orthopaedic surgeons: a biocompatible, osteogenic, mouldable, and self-hardening bone
substitute able to fill randomly shaped bone defects. The aims of this study was the evaluation of
the performance and safety of the bioactive bone substitute TricOs™ associated with a fibrin
sealant in regeneration of functional bone. The pre-clinical tests were conducted to optimize MBCP
granules size and ratio MBCP–FS VH S/D 4 (sheep maxillary sinus grafting, femoral epiphysis
defect in rabbits, long bone defects in sheep). A clinical study design was set up as an exploratory
prospective French multicentric phase II study sponsored by INSERM (Institut National de la Santé
et de la Recherche Médicale). The application was the TOV (Tibial Osteotomy of Valgisation)
using osteosynthesis and bone substitute: TricOs™ mixed with the fibrin sealant (FS VH S/D 4) for
filling the space created. The follow up is 13 months with safety checks, clinical assessments, highsensitivity
X-ray, and CT-scan imaging. A bone sample will be collected from the reconstructed
area at 12 months, during the osteosynthesis material removal surgery. The principal criterion is
CT-scan imaging performed 12 months after TOV surgery, before material removal, to assess
qualitative and quantitative bone reconstruction. Animals’ studies demonstrate that the biomaterial
is safe to use and shows osteoconductive properties, granules resorption and bone ingrowth at the
expenses of the implants. As for clinical trial, 7 patients are today included in the study: This paper
present the first results obtained from X-ray imaging during follow up.
Long-Term Tissue Reactions of Three Biomaterials in Craniofacial Surgery
Authors: Peltola Matti , Aitasalo Kalle , Tirri Teemu , Rekola Jami , Puntala A.
Published: March 2009

Successful craniofacial reconstruction needs both a well-known and a reliable
reconstruction material. However, there is often a lack of long-term knowledge of the tissue
reactions and healing process in the human body. In this study, frontal sinus obliterations with
bovine bone natural hydroxyapatite derivative (BHA), synthetic bioactive glass S53P4 (BAG) and
hydroxyapatite cement (HAC) were investigated with clinical, histologic, scanning electron
microscopic (SEM) and energy dispersive x-ray analysis (EDXA) 27, 12 and 3 years
postoperatively. The aim was to determine the long-term clinical biocompatibility of the used
materials. Histologic studies revealed bone formation with BHA particles and lamellar bone with
BAG granule remnants in close contact to the new bone formation. In HAC reconstruction there
was scattered fibroconnective tissue growth without new bone formation in the surface of HAC
implantation. Neither foreign body reaction nor any abnormal findings were seen. SEM studies
revealed a CaP layer on the surface of BAG granule remnants. In EDXA studies, composition
profiles showed Ca-, P- and Si- rich layers on the BAG granule surface. No differences were found
in CaO and P2O5 levels between BHA granules and HAC implantation and the surrounding bone.
All investigated biomaterials were well tolerated in long-term applications.
Preparation and Characterization of Boron-Containing Hydroxyapatite
Authors: Hayakawa Satoshi , Sakai Akihito , Tsuru Kanji , Osaka Akiyoshi , Fujii Eiji , Kawabata Kouji , Jaeger Christian
Published: March 2009

Boron-containing hydroxyapatite (BHAp) particles were synthesized by the wet chemical processing method and subsequent thermal treatment at the temperature ranging from 700-1200°C, and examined the effect of boron introduction on the microstructure of BHAp. The local structure around boron and phosphorus in the BHAp was analyzed by solid-state magic-angle spinning (MAS) nuclear magnetic resonance (NMR) spectroscopy. The heat-treatment above 700°C induced the thermal decomposition of HAp to β-TCP and then the chemical reaction between HAp and B(OH)3 was induced above 900°C, resulting in the formation of boron-substituted HAp particles accompanied by the formation of β-TCP and its transformation to α-TCP above 1200°C.
Preparation and Properties of Carbon Nanotube-Reinforced Hydroxyapatite
Authors: White Ashley A. , Windle Alan H. , Kinloch Ian , Best Serena
Published: March 2009

Composites of hydroxyapatite (HA) and multiwalled carbon nanotubes (CNTs) have been
prepared and characterised for potential application in major load-bearing medical devices. We have
studied the effect of nanotube surface chemistry, composite preparation methods, and heat treatment
conditions on the microstructure of the composites, dispersion of CNTs, and interaction between the
HA and CNTs. The samples were characterised using SEM, XRD, FTIR, and BET surface area. It
was found that, compared with pure HA, the composites had lower densities and higher surface
areas. Additionally, functionalisation improved the dispersion of CNTs in the HA matrix and the
interaction between the two phases.
Synthesis and Characterization of Mg-Containing Nano-Apatite
Authors: Hayakawa Satoshi , Osaka Akiyoshi , Tsuru Kanji , Fujii Eiji , Kawabata Kouji , Ando Kanae , Bonhomme Christian , Babonneau Florence
Published: March 2009

Nano-crystalline Mg-containing hydroxyapatite (Mg·HAp) were prepared by a wet
chemical method, for which selective adsorption of proteins was examined, taking bovine serum
albumin (BSA) and a pathogenic protein β2-microglobulin (β2-MG) as the model proteins.
Increase in the Mg content led to smaller crystallites and larger specific surface area (SA) of
Mg·HAps as well as zeta potential, while the amount both of BSA and β2-MG adsorption on
Mg·HAp particles. It is thus concluded that the adsorption of BSA and β2-MG on Mg•HAp was
associated with surface charges.
Effect of Surface Modification on Properties of Natural Hydroxyapatite/Polypropylene Composites
Authors: Suppakarn Nitinat , Sanmaung S. , Ruksakulpiwat Yupaporn , Sutapun Wimonlak
Published: March 2009

Cattle bone-based hydroxyapatite (HA) powders were prepared. Three types of silane
coupling agents, i.e. γ-aminopropyl triethoxysilane (APES), methyl trimethoxysilane (MTMS), and
γ-glycidoxypropyl trimethoxysilane (GPMS) were used to modify the HA surface. Untreated HA
powders and silane-treated HA powders were utilized to produce HA/polypropylene (PP)
composites containing a 60% (w/w) of HA content. Effect of filler surface modification on
properties of HA/PP composites were investigated. The results suggested that treating HA surface
with a silane coupling agent enhances interaction at HA-PP interface. Among the silane coupling
agents used in this study, APES is, on average, the most effective agent for enhancing stiffness of
HA/PP composites.
The Characterizations of Bacterial Cellulose and Dialdehyde Celluloses from Bacterial Cellulose
Authors: Feng Yu Hong , Li Jia Cheng , Lin Qiang , Pang Su Juan , Wang Xi Bin , Wu Zhou Xin
Published: March 2009

The characteristics and properties of bacterial cellulose and dialdehyde celluloses from
bacterial cellulose were studied by XRD, TG-IR and adsorption capacity testing. The crystal cell
parameters of BC were calculated and approximated to that of monocline crystal cell model. The
XRD profiles showed that the crystallinity degree of BC was 66%, and that of the DACs (12%
aldehyde) was 56%. The optimal adsorption capacities of pure water on dried BC and DAC were 12
g/g and 3.1 g/g respectively, and that of iron ion on dried BC and DAC were 11 mg/g and 6.9 mg/g
respectively. And the optimal adsorption capacity of hexanediamine on DAC was 700 mg/g, and
that of n-phenylene diamine on DAC was 490 mg/g. The IR result showed that the adsorption of
hexanediamine on DAC was physical adsorption, not chemical reaction under the experimental
conditions.
Electrospray Deposition of Bioactive Alkaline Phosphatase Coatings
Authors: de Jonge Lise , van den Beucken Jeroen J.J.P. , Leeuwenburgh Sander C.G. , Wolke Joop G.C. , Jansen John A.
Published: March 2009

Protein thin films were prepared by electrostatic spray deposition (ESD) from aqueous solutions of the enzyme alkaline phosphatase (ALP). ALP thin films with preserved functional properties were successfully deposited using the ESD technique. The biological activity of the deposited ALP films was investigated in vitro by immersing the ESD-coated titanium substrates in both simulated body fluid (SBF) and cell-culture medium. Mineral deposition occurred on substrates immersed in both SBF and medium. Various analytical techniques (SEM,XRD,FTIR,EDS) showed that the calcium phosphate layers deposited in SBF and medium differ in both crystallinity and morphology. The results demonstrated that ESD is a successful method for the deposition of biomedical coatings with enhanced functionality.
Novel Method of Hydroxyapatite Coating on Titanium Using Chemical Deposition
Authors: Rohanizadeh Ramin , LeGeros Racquel Z.
Published: March 2009

The aim of this study was to deposit an adherent apatite coating on titanium substrate using a two-step chemical deposition method. First, titanium substrates were immersed in an acidic solution containing calcium and phosphate ions, resulting in the deposition of a monetite (CaHPO4) coating. Second, the monetite crystals were converted to apatite by hydrolysis in NaOH solution. Composition and morphology of the initial and final coatings were identified using X-ray diffraction (XRD), Scanning Electron Microscopy, and Energy Dispersive Spectroscopy (EDS). The final coating was porous and the apatite crystals were agglomerated and followed the outline of the large monetite crystals. The average tensile bond of the coating was 5.2 MPa and cohesion failures were observed more frequently than adhesion failures. The coating adhesion measured using scratch test was 13.1N. In conclusion, this study showed the potential of a two-step chemical deposition method for depositing an adherent coating of apatite at low temperatures.
Newly Formed Bone around Implanted New Titanium Alloy: Ti-15%Zr-4%Nb-4%Ta
Authors: Nakada Hiroshi , Numata Yasuko , Suwa Taketoshi , Okazaki Y. , LeGeros Racquel Z. , Sakae Toshiro , Kato Takao , Kuwahara K. , Kobayashi Kihei
Published: March 2009

We have developed a new Ti alloy, Ti-15%Zr-4%Nb-4%Ta alloy (Ti-15-4-4) that showed higher biological safety and mechanical properties than the currently used Ti-6%Al-4%V alloy. The purpose of this study is to determine the biological performance of the new alloy. Ti-15-4-4 implants (machined or blasted) were placed in surgically created defects in rabbit femurs. The rabbits were sacrificed after 4, 8, 16, 24 and 48 weeks. Bone mineral density (BMD) and area of newly formed bone around the implants were measured using micro-CT. Results showed that the Ti-15-4-4 alloy is biocompatible and forms new bone around the Ti-15-4-4 implant, regardless of the surface treatment. The BMD and area of newly formed bone around the blasted implant surfaces were significantly greater than those around the machined surfaces. These results indicate that the new Ti-15-4-4 alloy has a potential for use as implants and has the advantage of improved mechanical properties described in earlier studies.
Synthesis and Phase Stability of Silicate-Substituted α-Tricalcium Phosphate
Authors: Massie Iain , Skakle J.M.S. , Gibson Iain R.
Published: March 2009

Silicate-substituted calcium phosphates have been shown to result in enhanced biological
performance compared to the corresponding, silicate-free, calcium phosphates. We have produced a
range of silicate-substituted alpha-TCP compositions using two different synthesis methods and two
different substitution mechanisms. Single phase compositions were only observed for a silicate
substitution of 1.3 wt% by both solid state synthesis and aqueous precipitation synthesis, although
the latter was the result of a design composition with a higher silicate substitution (3 wt%). The
silicate substitution resulted in small changes in the unit cell parameters of the alpha-TCP. More
importantly, this small level of silicate substitution had a strong effect on the thermal stability of the
alpha-TCP phase, with the silicate substitution stabilising the alpha-polymorph to lower
temperatures. This has an immediate advantage in that the quenching conditions are not as critical
for the production of silicate-substituted alpha-TCP compositions compared to silicate-free alpha-
TCP.
Protein Adsorption of Highly (001) Oriented Hydroxyapatite Coating Using Rf-Plasma Spraying
Authors: Inagaki Masahiko , Nakashima Hisashi , Saito Takao , Kameyama Tetsuya
Published: March 2009

The protein adsorption behavior was investigated for highly (001) oriented
hydroxypatatite coatings (HACs). Highly (001) oriented (HO-) HACs and HAC with low
orientation (LO-HAC) were prepared on titanium (Ti) substrates through a radio-frequency thermal
plasma spraying method. Sintered HA pellets (S-HA) was also prepared as a control. The solution
of 22 'g/100 'l PBS of the fluorescein-isothiocyanate (FITC) labeled bovine serum albumin
(FITC-BSA), immunoglobulin G (FITC-IgG) and cytochrom c (FITC-CCC) was separately
dropped on the surface of HACs and was incubated for 30 min. After the incubation, such HACs
were washed with the PBS additionally supplemented with 125mM NaCl and observed using a
fluorescence microscope. Fluorescence microscopic examination indicates that FITC labeled
proteins somewhat adsorbed on the HACs, while proteins adsorbed little on S-HA surface. In
particular, it can be seen that FITC-CCC adsorbed more prominently on the HO-HAC.
Durability of Zirconia-Based Ceramics and Composites for Total Hip Replacement
Authors: Gremillard Laurent , Chevalier Jérôme
Published: March 2009

Ceramics have been increasingly used in orthopaedics during the last 30 years. Their
biological inertness, high hardness and good mechanical strength make them excellent candidates
for components such as femoral heads and acetabular cup in Total Hip Replacement prostheses.
Currently used bio-inert ceramics – alumina and zirconia – give good clinical results, especially
compared to metal – polymer couplings. However, they are subjected to severe biological,
tribological and mechanical solicitations during more than fifteen years for the most successful
prostheses. They answer these solicitations by presenting specific degradation mechanisms. We will
thus examine the phenomena that can account for the long-term behaviour of zirconia components
(heads and cups) in THR prostheses.
Monitoring the Accelerated Setting of Portland Cement Based Dental Materials
Authors: Murphy J.C. , Hofmann M.P. , O’Beirne J.L. , Coomaraswamy K.S. , Shelton R.M.
Published: March 2009

Mineral trioxide aggregate (MTA) is a slow setting Portland cement (PC) based dental material for endodontic applications. The present study investigated the effect of adding either CaCl2 or Plaster of Paris (PoP) as setting accelerators on the development of the material properties and microstructure with reaction time for a PC based model system. Mechanical strength, density and relative porosity were measured after 1, 10 and 30days and the microstructure was assessed using scanning electron microscopy (SEM). The strength of all cements increased with time whereas material density and relative porosity decreased due to the progress of the hydration reaction. Cements with 5-10% CaCl2 in the liquid phase had a higher final strength and lower porosity than cements modified with 20wt% PoP in the cement powder, whilst PoP modified cement had a shorter setting time of 15min compared with 60min for 10% CaCl2 addition. The microstructure of the two modifications were noticeably different, with the CaCl2 modified cement having more interconnected needle-like crystals than seen in PoP modified cements, which may explain the higher strength of this cement.
Effect of Surface Treatments on Bonding Strength of Dental Ceramics to Resin Cements
Authors: Sato Hideo , Ban Seiji , Nawa Masahiro , Suehiro Y. , Nakanishi H.
Published: March 2009

The aim of this study was to investigate the effect of surface treatments on bonding
strength of two kinds of zirconia to three kinds of resin cements. After thermal cycling, the shear
bonding strength of both zirconia decreased in all the resin cements. The bonding strengths of two
resin cements in which primer contains silane dramatically decreased after the thermal-cycling
(p<0.01). Although the surface roughness of both zirconia sandblasted by 125-%m SiC was quite
larger than that by 70-%m alumina (p<0.05), there were no significant differences in the bonding
strength of the resin cement to both zirconia sandblasted by 70-%m Al2O3 and 125-%m SiC
(p>0.05).