bluuebunny/crossref_metadata_2025 huggingface dataset:
Multiphasic Biomaterials: A Concept for Bone Substitutes Developed in the "Pays de la Loire"
Authors: Daculsi G. , Chappard Daniel , Aguado Eric , Legeay G. , Layrolle Pierre , Weiss Pierre
Published: March 2009

This paper reports on the research into multiphase bone substitutes carried out by laboratories from the ‘Pays de la Loire’ region in France. This collaborative research was funded by both the French Government and the Regional Council in the period 2000-2007. Calcium phosphate bioceramics, polymers and combinations have been developed as bone substitutes for various maxillofacial and orthopaedic applications. These bone substitutes should support and regenerate bone tissue and resorb after implantation. In the bone tissue engineering area, they have been combined with autologous bone marrow cells or bioactive factors. The bone substitutes were tested in various animal models mimicking clinical situations or under pathological conditions (osteoporosis). In order to complete our research, the multiphase materials were also evaluated in clinical trials.
Comparison of the Biological Behavior of Wollastonite Bioceramics Prepared from Synthetic and Natural Precursors
Authors: Minarelli Gaspar Ana Maria , Saska Sybele , da Cunha L.R. , Bolini P.D.A. , García Carrodeguas R. , De Aza A.H. , Pena P. , De Aza P.N. , De Aza S.
Published: March 2009

Wollastonite bioceramics prepared from synthetic and natural precursors were implanted
in rats in bone and subcutaneous tissues. The implant sites were excised after 7, 30 and 120 days,
fixed, dehydrated, embedded in paraffin wax for serial cutting and examined under transmitted light
microscope. It was found a very similar behavior for both wollastonite bioceramics. They were
biocompatible, bioactive and biodegradable when implanted in rat bone. The synthetic ceramic was
more reabsorbable than the one from natural powder. When implanted in subcutaneous rat tissue,
both materials elicited a mild initial inflammatory reaction that practically disappeared after 120
days. Both materials were encapsulated with a very thin fibrous capsule and slightly reabsorbed at
their surfaces. None of the materials induced ectopic osteogenesis. According to the results, the
studied materials seem to be able for manufacturing reabsorbable bone implants.
Synthesis and Degradation Studies of Novel Calcium Polyphosphates
Authors: Jackson Lauren E. , Grover Liam M. , Wright Adrian J.
Published: March 2009

This paper describes a comparative investigation into the in vitro solubility of the
calcium polyphosphates, γ-Ca(PO3)2 and β-Ca(PO3)2. The differing arrangement of their
polyphosphates chains appears to result in significant dissolution of γ-Ca(PO3)2 polymorph over
the β-Ca(PO3)2 polymorph, which exhibits limited dissolution. These properties are discussed
with respect to structure and thermodynamic stability.
The Experimental Study of Culture of Osteoblast-Like Cells (MG-63) on Nanometer Magnetic Composite Substrate In Vitro
Authors: Wang M.Q. , Hou P. , Bao C.Y. , Weng Jie , Li Wei
Published: March 2009

The purpose of this study was to evaluate the cytotoxicity of nanometer magnetic composite via being cultured with osteoblast-like cells (MG-63). The osteoblast-like cell (MG-63) was utilized as the seed cell. The cells were cultured on the surface of nanometer magnetic composite. After union culturing, on the day 1, 3, 5, 7, the cytotoxicity of nanometer magnetic composite was evaluated by MTT method and the cell morphology was observed by SEM. Meanwhile, on the day 4, 7, 10, the alkaline phosphatase (ALP) activity was tested respectively. These results demonstrated that the typical cell morphology could be observed when the osteoblast-like cells were cultured on nanometer magnetic composite substrate in vitro. Cell proliferation and ALP activity became higher as the prolongation of cultivate time in the group of nanometer magnetic composite. The study showed that nanometer magnetic composite had a little inhibition to cell proliferation and ALP activity in vitro cell culture, as compared with the chitin and PLA fiber substrate. So the feasibility of nanometer magnetic composite as scaffold for bone tissue engineering should be studied further.
Initial Attachment of MC3T3-E1 Cells on Nano-HAp Surfaces
Authors: Kwon Un Hye , Han Jung Suk , Ryu In Young , Kim Dae Joon
Published: March 2009

The initial osteoblast like cell response to bioactive nano-sized hydroxyapatite (HAp) and
bioinert zirconia was evaluated with the cell morphology by SEM and cell adhesion proteins by
fluorescence microscopy. Surface roughness also measured by a confocal laser microscopy. The
surface roughness and topography was almost identical among specimens. The nano-sized HAp
specimens showed better initial cell adhesion and activity than bioinert zirconia ceramics.
Biodegradable Chitosan-Silicate Porous Hybrids for Drug Delivery
Authors: Shirosaki Yuki , Tsuru Kanji , Hayakawa Satoshi , Osaka Akiyoshi
Published: March 2009

Porous chitosan-silicate hybrids were prepared by freeze-drying the precursor sol
solutions synthesized from chitosan and 3-glycidoxypropyltrimethoxysilane (GPTMS).
Degradability of and the release of cytochrome C in to phosphate buffer saline solution (PBS) were
examined as a function of the GPTMS content. The hybrids were less degradable with larger
GPTMS contents, and the cytochrome C release profile was so controllable as to give either burst
release or slow one due to the GPTMS content. Thus, the present porous chitosan-silicate hybrids
were considered applicable to drug delivery systems.
Hydroxyapatite Ceramic Hip Survey: Ceramic/Ceramic Bearings
Authors: Buchanan James M. , Goodfellow Sally
Published: March 2009

This paper describes the clinical application of alumina ceramic and, more recently, Zirconia Toughened Alumina (ZTA), to the bearing surfaces of hip implants with a maximum follow up of fifteen years. Patients are assessed pre- and post-operatively using the Harris Hip Score. [1] X-rays are taken annually and, where appropriate, post mortem histological examination is carried out. Results are discussed. Some failures of alumina ceramic components have been seen and measures to prevent such incidents are described.
Characterization and Protein Adsorption Ability of Zinc, Iron and Magnesium Hydroxyapatite
Authors: Tonegawa Toru , Ikoma Toshiyuki , Yoshioka Tomohiko , Chen Guo Ping , Hanagata Nobutaka , Tanaka M.
Published: March 2009

The adsorption properties of metal ions containing hydroxyapatite (Ca10(PO4)6(OH)2,
HAp) were elucidated for the development of protein drug carrier. As-prepared metal ion containing
HAp nanocrystal showed plate-like morphology with 10-20nm in length and 5-10nm in width. The
metal ion containing HAp microparticles had higher specific surface area than the HAp microparticle.
The adsorption amount per unit area of HAp showed higher than those of metal ion containing HAp.
The adsorption behavior followed the Langmuir curves for each protein, indicating the monolayer
adsorption. The loaded amount of proteins could be one of the most important properties for the
application of drug delivery carrier.
Fabrication of Hierarchically Porous Bioactive Glass Ceramics
Authors: Yun Hui Suk , Kim Seung Eon , Hyun Yong Taek
Published: March 2009

Hierarchically 3D porous bioactive glasses (BGs) with various combination of both pore sizes and pore structures have been produced by multi-polymer templating, such as amphiphilic block copolymers, poly urethane (PU) forms, poly styrene (PS) beads, or methyl cellulose (MC), sol-gel method, evaporation-induced self-assembly process, and rapid prototyping technique. The amphiphilic block copolymers used for producing the meso pores into the BGs, which induces large specific surface area and subsequently carries with good bone-forming bioactivity of BGs. Each poly urethane form, poly styrene bead, and methyl cellulose adapted for the fabrication of macro pores. The rapid prototyping (RP) techniques introduced to produce 3D BGs scaffolds with giant pores.
Strength and Chemical Stability Due to Aging of Two Bone Void Filler Materials
Authors: Breding Karin , Engqvist Hakan
Published: March 2009

Injectable resorbable bone cements for bone void fillings are gaining in interest. The materials resorb in vivo with loss of void filling capacity and strength as a consequence. The objective with this study is to qualitative determining the dissolution behaviour for a calcium sulphate and a calcium phosphate cement as function of storage time in different storage medium and correlate to their strength development. Experiments were performed on a calcium phosphate based cement, Norian SRS, and a calcium sulphate based cement, MIIG X3. In the resorbtion study, the materials dissolution at different pH (3, 5 and 7) was compared over a period of 11 weeks. The materials compressive and biaxial flexural strength was measured after aging in phosphate buffer saline for up to 12 weeks. The proposed qualitative method to study dissolution behaviour of injectable biomaterials as function of time and medium were evaluated and proved to be useful. Both materials were dissolved after 3 weeks of storage in pH 3. MIIG X3 dissolved faster than Norian SRS at pH 5. At pH 7 both materials were stable over the test period of 11 weeks. For both materials the strength decreases with storage time. Norian had a higher compressive strength than MIIG X3 for the first week, after the first week the compressive strength was similar for the two materials. MIIG X3 showed a higher flexural strength than Norian during the full test period.
Timed-Release Calcium Sulfate Ceramic Nanocomposites as Bone Graft Substitutes
Authors: Mamidwar Sachin , Ricci John , Alexander Harold
Published: March 2009

Pure calcium sulfate (CS) is an excellent bone graft material because it is biocompatible,
completely biodegradable, osteoconductive, safe, nontoxic and angiogenic. It also has barrier
properties. However, its rapid degradation limits its use as a bone graft material. A nanocomposite of
CS and poly (l lactic acid) (PLLA) in a ratio of 96:4 was developed to overcome this problem. This
composite underwent slower degradation. It took 16 weeks for complete degradation whereas pure CS
takes only 4 weeks. When implanted in bone defects in rabbits, it underwent complete degradation and
stimulated vigorous bone formation.
PL DLLA Calcium Phosphate Composite Combined with Macroporous Calcium Phosphate Cement MCPC® for New Surgical Technologies Combining Resorbable Osteosynthesis and Injectable Bone Substitute
Authors: Jouan Gaelle , Goyenvalle Eric , Aguado Eric , Cognet Ronan , Moreau Françoise , Bourges Xavier , Daculsi G.
Published: March 2009

Resorbable osteosynthesis based on PLLA and derivatives will be associated to bone substitute for bone reconstruction. We have performed rand evaluated a composite combining PL DLLA and Biphasic calcium phosphate able to have a), a better controlled hydrolysis in the purpose to preserve on time the mechanical property, and b), for long term efficiency, bone ingrowth at the expense of the osteosynthesis and the associated bone substitute. A new calcium phosphate cement MCPC® was tested with such composite. The novel macroporous calcium phosphate cement MCPC sets to poorly crystalline apatite after mixing the powder component and an aqueous solution. Interconnective macroporosity was induced on time by resorption of one part of the MCPC®. The multiphasic calcium phosphate components in the cement, are resorbed at different rates allowing the replacement by newly formed bone. This study reports the biocompatibility and the interactions of a composite using PL DLLA (Poly [L-Lactide-co-D,L-Lactide] acid) charged with biphasic calcium phosphate granules and a self setting calcium phosphate cement of new generation.
Preparation of the Hydroxyapatite/Collagen Three-Dimensional Scaffold from its Membrane
Authors: Kikuchi Masanori
Published: March 2009

Effect of osteogenic activities of MG63 on the HAp/Col membrane was examined at day 10 and 14 by reverse-transcript and real-time polymerase chain reactions. Osteogenic activities of MG63 were upregulated by culture them on the HAp/Col membrane in comparison to those on tissue culture polystyrene. The novel three-dimensional HAp/Col scaffold was prepared from the HAp/Col wavy membrane. The cylindrical HAp/Col scaffold was successfully prepared and indicated at least 2.5-times higher compressive strength and Young's modulus compared to the previous HAp/Col composites. The novel scaffold could be useful for regenerative medicine.
Preparation and Evaluation of Nano-Hydroxyapatite/β-Tricalcium Phosphate/Chitosan Composite Scaffolds for Bone Tissue Engineering
Authors: Lin T. , Zhang S.M. , Li J. , Zhang L. , Liu Y.H. , Xue Y.H.
Published: March 2009

The composite scaffolds with nine different ratios of nano-HA and ß-TCP content were fabricated
by using lyophilization method. Their microscopy, physical and chemical properties were investigated by
using scanning electron microscopy (SEM), X-ray diffraction (XRD), and fourier transformed infrared
(FTIR) spectroscopy. MTT test was applied to quantitatively assess the number of viable cells attached and
grown on the scaffolds. And the result showed that the amount of cells on the scaffold containing 30% by
mass of nano-HA was significantly higher than the other samples.
Antibiotic-Containing Polylactide-Co-Glycolide and Porous β-Tricalcium Phosphate Composite for Treating Osteomyelitis
Authors: Tamazawa Gaku , Ito Atsuo , Miyai Takahiro , Matsuno Tomonori , Sogo Yu , Satoh Tazuko
Published: March 2009

A composite of co-polymer of lactic and glycolic acids (PLGA) loaded with gatifloxacine
(GFLX), an antibiotics, and a β-tricalcium phosphate (βTCP) porous ceramic body was prepared by
a solvent-free process in which no toxic solvent was used. The GFLX-loaded PLGA released GFLX
for 8 weeks in Hanks’ balanced solution. The inhibitory zone diameter (26.25±0.95 mm) for
GFLX-containing PLGA disk against S. milleri was significantly larger than 18 mm, and
comparable to that (24.88±1.6 mm) for the KB paper disk containing 5 μg of GFLX/disk. This
means that the GFLX-containing PLGA has the clinical efficacy. The molten PLGA containing
GFLX was successfully loaded in the pores and on the surface of the porous βTCP ceramic at
120 °C at a reduced pressure of 0.02 MPa. The composite of GFLX-loaded porous βTCP ceramic
would be promising for treating osteomyelitis.
In Vitro Bio-Mineralization Process
Authors: Sandri Monica , Tampieri Anna , Bertinetti Luca , Boskey Adele
Published: March 2009

The present work describes the development of biomimetic composites materials for bone tissue substitution and repair. At this purpose a biomimetic approach was used and apatitic phases were nucleated on macromolecular matrices like natural collagen, which act as template and induce peculiar physico-chemical features in the mineral phase.
Surface Structure and Apatite-Forming Ability of Silicone Rubber Substrates Irradiated by Cluster Ion Beams
Authors: Masakazu Kawashita , Araki Rei , Takaoka Gikan H.
Published: March 2009

Silicone rubber substrates were irradiated at an acceleration voltage of 7 kV and a dose of
1×1015 ions/cm2 by the simultaneous use of oxygen cluster and monomer ion beams, and then soaked
in CaCl2 solution. Apatite-forming ability of the substrates was examined using a metastable calcium
phosphate solution that had 1.5 times the ion concentrations of a normal simulated body fluid
(1.5SBF). After the irradiation, the silicon oxide clusters (SiOx) were formed at the silicone rubber
surface. The hydrophilicity of the substrates was remarkably improved by the irradiation. The
irradiated silicone rubber substrates formed apatite in 1.5SBF, whereas unirradiated ones did not form
it. These results suggest that the functional groups such as Si–OH and/or COOH groups induced
apatite nucleation in 1.5SBF.
Influence of Cross-Linking Agents on Apatite-forming Ability of Pectin Gels
Authors: Ichibouji Takashi , Miyazaki Toshiki , Ishida Eiichi , Ashizuka Masahiro , Sugino Atsushi , Ohtsuki Chikara , Kuramoto Koichi
Published: March 2009

Natural bone is a kind of organic-inorganic hybrid composed of collagen and apatite
crystals with a structure that provides specific mechanical properties such as high fracture toughness
and flexibility. Materials exhibiting both high flexibility and bioactivity similar to natural bone are
required for novel bone-repairing materials in medical fields. We expect that we can design such
materials by mimicking the bone structure. Biomimetic process has been paid much attention where
bone-like apatite is deposited on organic polymers in simulated body fluid (SBF). In this study, we
investigated influence of cross-linking agents on apatite-forming ability of pectin gels. Pectin is a
polysaccharide abundant in carboxyl group. Pectin gels were prepared by cross-linking of pectin
aqueous solutions with calcium ions or divinylsulfone (DVS). Apatite-forming ability of the gels was
examined in SBF. The citrus-derived pectin showed tendency to form the largest amount of the apatite
independent on a kind of cross-linking agents in SBF.
Biodegradable Adhesive (LYDEX) with Hydroxyapatite Granules
Authors: Yamamoto T. , Fujibayashi Shunsuke , Nakajima Naoki , Sugai Hajime , Hyon Suong Hyu , Nakamura Takashi
Published: March 2009

A new biodegradable adhesive(LYDEX) which is based on Schiff base formation had
developed. LYDEX is easy to control the setting time and degradation speed and it has no risk of
infection. In the previous study, LYDEX showed high bonding strength and low cytotoxicity in
vitro[1]. In the present study, good bone repair was seen in rat bone defect models, especially in
rapidly degrading type. On the other hand, slowly degrading type kept its shape longer without
excessive inflammation. In rabbit critical defect model with hydroxyapatite granules (HAs), more
newly formed bone was seen in rapidly degrading group and hydroxyapatite group, in 3weeks. In
6weeks, more new bone was seen in slowly degrading type group, whereas, almost no new bone
was seen in deep area of the fibrin group, in 12weeks. Direct bonding between HAs and bone was
seen in HA group and LYDEX groups. These findings suggest that LYDEX with hydroxyapatite
granules can be a promising bone substitute.
Apatite-Forming Ability of Titanium Metal Enriched with Calcium Ion on its Surface
Authors: Kizuki Takashi , Kawai Takahiro , Takadama Hiroaki , Matsushita Tomiharu , Kokubo Tadashi , Nakamura Takashi
Published: March 2009

In order to study method for preparing bioactive titanium metal, calcium ions were
attempted to be incorporated into the surface of the titanium metal by ion exchange method. Titanium
metal was soaked in 5M NaOH solution and 100mMCaCl2 solution and subjected to heat treatment.
About 5 atom% of Na was incorporated into the surface of the titanium metal by the NaOH treatment
This Na was completely replaced with calcium ion by the CaCl2 treatment and maintained even after
the heat treatment. Critical detaching strength of the surface layer to the substrate of NaOH-treated
titanium metal was a little increased by the CaCl2 treatment and remarkably increased by the heat
treatment. Apatite-forming ability of the NaOH-treated titanium metal in SBF was increased by the
CaCl2 treatment, but decreased by the subsequent heat treatment.
Development of Template-Assisted Electrohydrodynamic Atomization Spraying for NanoHA Patterning
Authors: Li X. , Huang Jie , Edirisinghe Mohan J.
Published: March 2009

Topography of the surface plays an important role in cellular responses. A novel method,
called template-assisted electrohydrodynamic atomization (TAEA) spraying, was developed to
create surface topography of hydroxyapatite (HA) on metallic surfaces. In this work, by varying the
core process parameters (e.g. flow rate, applied voltage and distance between substrate and needle),
the optimization and development of the TAEA process with nanoHA suspension is investigated
with the aim of preparing a nanostructured HA coating with patterning of high resolution for
biomedical applications.
Calcium Titanate Reaction Layers on TiAl6V4 Implants
Authors: Ploska Ute , Berger Georg , Jörn Daniela , Willfahrt Manfred , Hackbarth Andreas
Published: March 2009

Discs of TiAl6V4 were cleaned and stored in calcium containing salt melt. The
characterization of the reaction layer was realized by TF-XRD, SEM, SIMS, AES, and eddy
current. The release of Ca ions was determined after storing the samples in TRIS-HCl buffer
solution under physiological conditions for at least 16 weeks. The thickness of the generated
calcium titanate layer varied in dependence on salt melt composition, temperature, and storing time
in the range of 0.4-0.9.m. The Ca content of the layer depends on melt composition, temperature
and storing time and was in the range from 5-42.g●cm-2 in correlation with the thickness. The
morphology of the layers also changed in dependence on the salt melt composition and the storing
time and temperature.
Designed Solution to Coat Titanium Sheets with Octacalcium Phosphate
Authors: Resende Christiane Xavier , Platt Gustavo Mendes , Dille Jean , Bastos Ivan Napoleão , de Almeida Soares Gloria Dulce
Published: March 2009

In this work, a solution able to precipitate calcium phosphate in titanium samples was
studied. At first, a thermodynamic analysis of the proposed solution was conducted using a
computational simulator that considers most of chemical reactions and evaluates parameters such as
activity of species. After this procedure, experimental tests were performed in order to confirm this
precipitation. With the use of TRIS at concentration of 50mM, the deposits were basically
composed of octacalcium phosphate, as confirmed in some characterization techniques. The deposit
presents a thickness of approximately 15μm after a 7-day exposure in the designed solution.
Biocompatibility of Titanium Based Implants with Diamond-Like Carbon Coatings Produced by Plasma Immersion Ion Implantation and Deposition
Authors: Uzumaki E.T. , Lambert C.S. , Belangero W.D. , Zavaglia Cecília A.C.
Published: March 2009

A great number of studies have shown that diamond-like carbon (DLC) coatings could be
developed for orthopaedic implants, but few articles have been published about in vivo evaluation.
In this study, DLC coatings were deposited on titanium alloy (Ti-13Nb-13Zr) implants using the
plasma immersion implantation and deposition (PIII-D), and the in vivo biocompatibility of DLC
coatings was evaluated into both muscular tissue and femoral condyles of rats. Results indicate that
DLC coatings are biocompatible in vivo, and DLC-coated implants were observed directly bonding
to bone without any intervening soft tissue layer.
Gelatin Immobilization on Titanium Surface by Gamma Irradiation
Authors: Kuang Hong Hai , Kuang Yun Yun , Chen Ze Hong , Wu Zhi Hong , Jiang Bo
Published: March 2009

Radiation induced graft polymerization of 2-hydroxyethyl acrylate (HEMA) on titanium
surface and couple gelatin have been studied in the paper. The composition and properties of
surface modified titanium were investigated by several surface sensitive techniques: X-ray
photoelectron spectrum (XPS) and scanning electron microscopy (SEM). Results of the
technological measurements show that surface chemistry is affected throughout the surface
modification process, finally leading to a complete and homogeneous vinyl compound overlayer on
top of the titanium samples. And the modified porous titanium exhibits an interesting mineralization
in simulated body fluid (SBF) and an adsorptive property in bovine serum albumin (BSA).
Immobilization of Bovine Serum Albumin on Titanium through Plasma Polymerization of Allylamine and Crylic Acid
Authors: Rao H.Q. , Wang Jian Xin , Lu X. , Feng Bo , Weng Jie
Published: March 2009

In the present work, technique of plasma polymerization was used to generate amido (-
NH2) and carboxyl (-COOH) on titanium surface for immobilizing bovine serum albumin (BSA).
After plasma polymerization of allylamine and crylic acid, the contact angle with respect to double
distilled water significantly increased. Surface components were detected by X-ray photoelectron
spectroscopy and Fourier transform infrared reflection-absorption spectroscopy. The results showed
that BSA was successfully immobilized on the titanium surface and the amounts of BSA on
specimens were relied on the properties of thin film deposited through plasma polymerization,
which was corresponding to the ultraviolet spectrophotometer result.
Osteoconductivity of Titania Films Prepared by Electron-Cyclotron-Resonance Plasma Oxidation of Implant Titanium
Authors: Masumoto Hiroshi , Goto Takashi , Orii Yusuke , Honda Yoshitomo , Suzuki Osamu , Sasaki Keiichi
Published: March 2009

Surface titanium oxide (TiO2) films were fabricated on implant titanium (Ti) at low
temperatures by electron-cyclotron-resonance (ECR) plasma oxidation. The relationship among
the oxidization conditions, crystal structure, morphology and osteoconductive property were
investigated. Although crystallized TiO2 film was not prepared by thermal oxidation at 300°C,
crystallized rutile-type TiO2 film was formed by ECR plasma oxidation at 300°C. Rough
morphology was observed in the substrate surface oxidized by ECR plasma. Mixtures of
octacalcium phosphate (OCP) and dicalcium phosphate dihydrate (DCPD) were observed after
calcification. The XRD peak intensities of the OCP and DCPD formed on the ECR plasma
oxidized Ti were larger than those of calcified on the thermal oxidized Ti. ECR plasma
oxidation at low temperature would induce osteoconductive calcium phosphate on implant Ti.
Metallic Ion Release from Titanium Alloy and Stainless Steel Coated with Electrolytic Calcium Phosphate (HA)
Authors: Ionita D. , Ciohodaru L. , Prodana Mariana , Demetrescu Ioana
Published: March 2009

The corrosion behavior of titanium alloys and 316L stainless steel has been evaluated and
compared with coated materials. The corrosion current and the corrosion rate were evaluated by
electrochemical techniques.
The ions release from titanium alloys and 316L stainless steel were analyzed using ICP-MS and the
HA coatings were observed using FTIR analysis.
Investigation of Aged Dispersion Ceramics by Means of Hip Simulator
Authors: Oberbach Thomas , Begand Sabine , Glien Wilfried , Kaddick Christian
Published: March 2009

Wear of hip implants is a significant problem for the life expectancy of artificial joints.
By using alumina ceramic on ceramic couplings the wear can be decreased. But for further
improvement of the safety of THR the aim is the development of new ceramic materials. For
orthopaedic applications an Alumina Toughened Zirconia Ceramic ATZ (80% ZrO2-20%Al2O3)
and a Zirconia Toughened Alumina ZTA (25% ZrO2-75%Al2O3) were tested regarding their
tribological behaviour by means of hip simulator testing after hydrothermal treatment. The absolute
wear amount for the aged samples after 5 million cycles is slightly increased on a very low level,
but even less wear than for common alumina pairings. In consideration of these excellent results
both dispersion ceramics are highly suitable for long term applications.
Design of Nanoporous Alumina Structure and Surface Properties for Dental Composite
Authors: Azevedo C. , Tavernier B. , Vignes Jean Louis , Cenedese Pierre , Dubot Pierre
Published: March 2009

Recent studies showed that the particle size of fillers, using for the reinforcement of
dental resin composites, should be as small as possible to provide the maximum surface area for
bonding to resin monomer, and should be kept well dispersed so as to be functionalized by a silane.
In the present study, porous alumina monoliths with high specific surface area, measured by the
Brunauer-Emmett-Teller (B.E.T.) method, were obtained using a novel preparation method.
Structure and surface reactivity have been investigated as functions of temperature and chemical
treatments. The impregnation of the as-prepared material by Triméthyletoxysilane (TMES)
stabilized alumina with high specific surface area at higher temperature. A FTIR study has
described the effect of TMES treatment and temperature on the structure of the material. The use of
allyldimethoxysilane (ADMS) as a probe molecule for measuring the surface reactivity, has allowed
us to show that the treatment of samples with TMES and their reheating at 1300°C results in
adsorption sites which give stronger chemical bonds. This preliminary study has, therefore, allowed
us to optimize the structural and surface treatment of experimental fillers before their use in the
reinforcement of resin composites or resin-modified glass-ionomer cements.
In Vitro Study on Bleached Enamel
Authors: Wang Xiao Jie , Mihailova Boriana , Klocke Arndt , Heidrich Stefanie , Bismayer Ulrich
Published: March 2009

The surface crystal chemistry of enamel treated with peroxide-based (the commercial
product Opalescence Xtra Boost as well as aqueous solutions of H2O2) and citric-acid-containing
bleaching agents (the commercial product Rapid White as well as aqueous solutions of C6H8O7)
were studied by Attenuated Total Reflectance Infrared Spectroscopy and electron-probe
microanalysis. The results show that the treatment with H2O2-based reagents leads to no side effects
on the enamel superficial layer, whereas C6H8O7-based agents deteriorate the enamel mineral
component. Hence, bleaching with citric-acid-containing products cannot be recommended.
Fabrication of Tailored Hydroxyapatite Scaffolds: Comparison between a Direct and an Indirect Rapid Prototyping Technique
Authors: Deisinger Ulrike , Hamisch Sabine , Schumacher Matthias , Uhl Franzika , Detsch Rainer , Ziegler Günter
Published: March 2009

In the last few years new fabrication methods, called rapid prototyping (RP) techniques,
have been developed for the fabrication of hydroxyapatite scaffolds for bone substitutes or tissue
engineering applications. With this generative fabrication technology an individual tailoring of the
scaffold characteristics can be realised. In this work two RP techniques, a direct (dispense-plotting)
and an indirect one (negative mould technique), are described by means of fabricating
hydroxyapatite (HA) scaffolds for bone substitutes or bone tissue engineering. The produced
scaffolds were characterised, mainly regarding their pore and strut characteristics. By these data the
performance of the two fabrication techniques was compared. Dispense-plotting turned out to be the
faster technique while the negative mould method was better suited for the fabrication of exact pore
and strut geometries.
A Comparative Study of the Porous Structure of a Scaffold for Effective Tissue-Engineered Bone Regeneration
Authors: Yoon D.H. , Park Eui Kyun , Kim Suk Young , Lee J.M. , Shin H.W. , Shin Hong In
Published: March 2009

To develop a suitable scaffold for tissue-engineered bone regeneration, we compared the efficiency of tissue-engineered bone regeneration according to the porous structure of calcium metaphosphate (CMP) ceramic scaffolds. Each scaffold was prepared with a sponge method and a foam-gel method, respectively. Both scaffolds, having either interconnected trabecular pores formed by the sponge method or fully interconnected globular pores formed by the foam-based technology, were not cytotoxic and elicited neither an immune nor an inflammatory response regardless of geometry and fabrication method. The fully interconnected globular porous scaffold showed more favorable compression strength and facilitated osteogenic repair by favoring cellular attachment and osteogenic differentiation with good osteoconductivity compared to the interconnected trabecular pore structured scaffold. These results suggest that the fully interconnected globular porous structure would be more suitable for both a bone substitute and scaffold for bioactive material-based or cell-based tissue bone regeneration.
Biomimetic Smart Hydroxyapatite/Biphasic Tricalcium Phosphate Biomatrices Induce Bone Formation
Authors: Ripamonti U. , Richter P.W. , Nilen R.W.N. , Ramoshebi L.N. , Renton L. , Heliotis M.
Published: March 2009

Long-term studies in the non-human primate Papio ursinus were set to investigate the
induction of bone formation in biphasic hydroxyapatite tricalcium phosphate (HA/TCP) biomimetic
matrices, 20/80 and 40/60, respectively. Biomimetic matrices were implanted in the rectus
abdominis and in calvarial defects of 4 adult Papio ursinus. Morphological analyses on day 90 and
365 showed significant induction of bone formation within concavities of the biomimetic matrices
implanted in both heterotopic and orthotopic sites with resorption of the implanted biomimetic
matrices. The smart biomimetic matrices induced de novo bone formation even in the absence of
exogenously applied osteogenic proteins of the transforming growth factor-β superfamily.
Diamond Turning Freeform Optics
Authors: Jiang W. , Tse Bill , Louie Roy , Chan Frankie
Published: March 2009

Freeform optics fabrication has become one of the hottest topics in optics industry in recent years. Although it still remains a challenge, many have tried different ways of manufacturing it. Some have achieved degrees of success. By means of a Nanotech 350-FG five axis diamond turning machine, we too have successfully produced some prototype freeform optics and lens arrays with Slow Tool Servo and Milling method. The produced freeform optics are mainly for automobile LED headlamps and the lens arrays are for LED illumination. In order to produce the freeform optics, we developed our own DT Slow Tool Servo program which is capable of generating a DT program for diamond turning a universal/general 3D freeform surface. Slow Tool Servo technique and Diamond Milling technique were mainly employed to produce these freeform surfaces. The manufacturing process and machining parameter details will be given in the paper. The two main methods we used will be compared and discussed as well. In measuring the freeform surface, a 3D white light interferometer was used to scan and obtain the surface coordinates. The software made by ourselves enabled us to compare the measure results of the work piece with that of the design drawings. The deviation of our finished forms is within 5 um from that of the nominal. The surface quality Rq is about 10 nm. Measuring equipment and methodology will also be discussed in the paper.
The Influence of Light-Cured Repairing on the Stiffness of Composite Material
Authors: Yu Xiao Lei , Zhao Zhi Min , Yu Hong Min
Published: March 2009

With the wide application of composite materials in aeronautics industry, the repairing technology of the composite materials has become a much discussed research topic in material science. Adopting the laser speckle photography technology, this paper focuses on the influence of light-cured repairing to the stiffness of composite materials, and the feasibility of light-cured repairing technology with experiment has been prove in the paper. The research results show that light-cured repairing technology has no evident influence on the stiffness of composite materials and therefore this technology is applicable to fast-repairing of damaged composite materials. This research is of great significance to the application of future researching of composite materials.
Effect of Different Coating Materials on Cutting Performance in High-Speed Machining of Mold Steels
Authors: Lin Shen Yung , Yu S.H. , Wu M.L.
Published: March 2009

Different materials coated on milling tools (tungsten carbide) such as TiCN, TiAlN, TiN
and DLC are integrated in this study for the analysis of cutting performance such as tool wear,
surface roughness and noise induced in high-speed machining of mold steels such as NAK80 and
SKD61 under different combinations of cutting conditions. The study attempts to find out the
advantages and adaptabilities in various coating materials being suitable for which cutting
circumferences with specific performance request.
High-speed milling experiments of NAK80 and SKD61 mold steels with four materials coating
tools were carried out in the laboratory. The tool wear was measured through the toolmaker’s
microscope and the roughness of the machined surface was measured by the roughness measuring
instruments after each surface layer was removed from the workpiece in the experiment. Besides,
the noise-mediator was used to detect cutting noise during each surface layer workpiece removing
of high-speed milling process, and the curl chips removed from the workpiece were also collected
for the result verifications.
Good surface quality and small amount of tool wear can be achieved under the cutting conditions
of high-speed revolutions, small feed rate and small depth of cut for four materials coating tools.
From the observations of the annealing temperature from the removed chips and the analysis of the
cutting noise levels, TiAlN material coating tool has the better tool life and it is suitable for rougher
high-speed machining, while DLC material coating tool only has a good surface roughness in
shallow cut and hence it is not suitable for high-speed machining of mold steel with excellent
cutting performance request.
Novel Algorithm for Computer-Aided Alignment of Wide Field of View Complex Optical System
Authors: Yang Xiao Fei , Han Chang Yuan
Published: March 2009

With the advent of the new complex optical system, alignment technology is necessary.
In this paper, is presented an alignment algorithm whose main idea is composed of damped least
square method and singular value decomposition method. In addition, the how and why to enter the
damped factor into algorithm is explained. According to this algorithm, an alignment software
package was compiled and compared self-compiled software with alignment package of CODE V.
Results show that, this self-compiled software is much more valid than alignment package of
CODE V. For a field of view of 2° R-C system, average MTF over the field of view was greater
than 0.3 at 50 line pairs /mm.
Evaluating Frequency Error Property of Wavefront of Large Optics by PSD Collapse
Authors: Cheng Xiao Feng , Zheng Wan Guo , Jiang Xiao Dong , Ren Huan , Yuan Jing , Yuan Xiao Dong , Zhang Lin , Xu Xu
Published: March 2009

Operation of two-dimensional Power Spectral Density (2-D PSD) of large optics
wavefront is briefly described and PSD collapse is introduced to evaluate the intermediate
frequency error property of wavefront. As PSD collapse is Radon transform projection of 2-D
Power Spectral Density at any angle, all valid data of wavefront of optics are used in calculation of
the PSD collapse and the features of 1-D PSD were inherited in PSD collapse. Although PSD
collapse is as same as 1-D PSD in unit and behavior style, it is better for evaluating intermediate
frequency error property of optics wavefront than 1-D PSD or 2-D PSD. As PSD collapse
calculation uses all valid data of evaluated optics wave front and can be directly perceived through
its profile, the PSD collapse may possibly be the standard evaluating method of PSD.
Highly Efficient and Unusual Structure White Organic Light-Emitting Devices Based on Phosphorescence Sensitized 5,6,11,12-Tetraphenylnaphthacene
Authors: Jiang Wen Long , Duan Yu , Li Hui Ying , Li De Chang , Ding Gui Ying
Published: March 2009

Highly efficient and unusual structures white organic light-emitting devices were fabricated based on phosphorescence sensitized 5,6,11,12-tetraphenylnaphthacene. The device structure was ITO / NPB (30 nm)/CBP: 10% DPVBi (10 nm)/CBP (5 nm) /CBP:x% Ir(ppy)3 : y% rubrene (20 nm)/ CBP (5 nm)/ CBP: 10% DPVBi (10 nm)/BCP (10 nm)/ Alq3 (30 nm)/LiF(0.5 nm)/Al, where NPB is N,N '-bis- (1-naphthyl)- N,N ' –diphenyl -1, 1 '- biphenyl-4,4 '-diamine as a hole transporting layer, CBP 4,4,N,N’-dicarbazolebiphenyl as host,DPVBi is 4,4 '-bis(2,2 -diphenyl vinyl)-1,1 '-biphenyl as blue fluorescent dye，Rubrene is 5,6,11,12,-tetraphenylnaphthacene as fluorescent dye,Ir(ppy)3 is factris (2-phenylpyridine) iridium as phosphorescent sensitizer .BCP is 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline as hole-blocking layer, and Alq3 is tris(8- hydroxyquinoline) aluminum as an electron-transporting layer. In this device, phosphorescent emissive layer was sandwiched between two blue fluorescent doped ones. This architecture allowed for resonant energy transfer from both the host singlet and triplet energy levels that minimized exchange energy losses. Thus, a WOLED with a maximum luminous efficiency of 11.63 cd/A, a maximum power efficiency of 7.37 lm/W, a maximum luminance of 31770cd/m2, and Commission Internationale de L’Eclairage coordinates of (0.34.0.36) was achieved.
Modulation Transfer Function for a Multichannel Laser Induced Fluorescence Analyzer and its Numerical Calculation
Authors: Shi Yan , Wang Li Qiang , Zheng Hua , Wang Jie , Lu Zu Kang
Published: March 2009

In this paper, the modulation transfer function with aberration of a multichannel laser
induced fluorescence analyzer is presented. Based on an f-theta lens, the confocal system was used
both to transform the exciting laser and to collect the fluorescence emitted from sample. The total
MTF is the combination of that of both systems. A simple method for the numerical calculation of
that was also given. From the calculating result we could conclude that the aberration had poor
impact on the MTF of a confocal multichannel fluorescence analyzer and the imaging performance
was uniform in the full field.
Aberrations of the Human Eye across the Horizontal Visual Field
Authors: Quan Wei , Song Gui Cai , Liu Fu Yun , Wang Zhao Qi
Published: March 2009

Aberrations of the human eyes in the horizontal visual field were measured with
modified Hartmann-Shack wave front sensor. The characteristic of third to tenth order Zernike
aberration rms both temporally and nasally out to 50° is as follows: considerable differences
occur among subjects in the pattern of aberrations, particularly for the dominating second-order
aberrations; the third to tenth order Zernike aberrations increase with the visual angle, but the
increscent magnitude decreases as the Zernike order increases; in despite of imperfect
symmetry, the increscent magnitude is the same on the whole; the third-order Zernike
aberrations increases up to 2 times from 0° to ±50° visual angle, the forth-order up to 1.8 times,
and the fifth to tenth order up to 1.7~1.3 times.
Design of Geometric Error Measuring System on a Miniaturized Machine Tool with Optics
Authors: Wang Wei , Kweon Sung Hwan , Kim Young Suk , Yang Seung Han
Published: March 2009

Manufactured miniature parts conventional machine tools are substituted by mini-scale manufacturing system called miniaturized machine tool (mMT). However, calibration of mMT is extremely difficult due to its small dimensions. This paper presents a novel optical measuring system to measure integrated geometric errors namely a) three translation errors and b) three rotational errors. The squareness error between two moving axes was calculated by least-square method. These 7-DOF geometric errors were acquired simultaneously in one setup for each motion direction. The proposed measuring system consisted of two laser diodes, two beam splitters and three 2D position sensing detectors (PSDs). Configuration of this measuring system was proved by homogenous transformation matrix (HTM), and the relationship between PSD readings and geometric errors calculated by the algorithm were derived according to the configuration. Simulation were carried out to prove the validity of this algorithm. Sensitivity analysis based on mounting errors of system components is also presented in this paper. It is useful for further experiments in alignment of system components.
An Issue and its Processing in PIS Testing
Authors: Xu Jin , Li Yan , Chen Zhe Bo , Ni Xu Xiang , Lu Zu Kang
Published: March 2009

In PIS (Programmable Imaging System) testing, where the spatial frequency of the
spatial light modulator is inconsistent with that of the image device, Morie Fringes are generated.
To further develop the PIS instrument, it has to abate the effects of Morie Fringes on the image
quality. In this paper, we implemented an approach using spatial filtering in the Fourier Spectrum.
Since “ringing” phenomenon is caused by the “notch filter”, to prevent it, a multiple-point Gauss
Filter based on the “notch filter” has been designed. The tests have indicated that this approach can
efficiently reduce the effects of the issue on the image quality, and the images reconstructed are
clear and almost free from “ringing”,thus reaching the requirements for the instrument.
The Application of Surface Fairing Technique in Progressive Lens Processing
Authors: Du Jian Jun , To Suet , Cheung Chi Fai , Lee Wing Bun , Miao Xiang Wen
Published: March 2009

Based on the analysis of characteristics of progressive lens, it can be found that lens
uneven change of curvature is an important reason of defect on progressive lens processed by
single-point diamond cutting technique. By applying least square fairing method to fair the surface
which is fitted and interpolated by Double Cubic B-Spline method, the curvature change of
progressive surface becomes even. The processing experiment shows that the method in this paper
can eliminate the defect effectively in the ultra-precision processing of progressive lenses.
Design of a Highly-Efficient Light Guide Plate for the Edge Lighting Backlight Module
Authors: Chao Paul C.P. , Liao Lun De , Chiu Chi Wei , Shen Chien Yu
Published: March 2009

This study develops a highly-efficient light-guide plate for edge lighting backlight
module that has no optical films. The light guide plate is designed to control the angle of the
incident rays to the top surface from light source, to get the highest uniformity of intensity for thin
edge lighting backlight system applications. The micro-prisms of pyramidal shape on the top
surface can highly-efficient collimate with the light rays. Another micro-prism of v-cut shape on the
bottom surface can reflect the incident light into the front direction and mixing the rays in the lightguide
plate with the high uniformity. A novel design concept of the v-cut is the regular density
varies of the cut in the LGP. The modeling simulation program, employing a Monte Carlo method
based on TracePro software, has optimized the shape of the pyramidal micro-prisms on the top
surface and the density distribution condition of the v-cut micro-prisms on the bottom surface, also
the multiple scattering characteristics. The two types of the micro-prisms at the top and bottom
surface can be highly recommended for the uniformity of the brightness via the optimal design
process. Future work is warranted on improving the optical efficiency by using light-emitting
diodes as a light source. The backlight module will allow us to increase the optical efficiency and to
lower the total cost in portable LCD applications. The study confirms that a uniformity of
brightness can be achieved without using any optical films, resulting in a high uniformity of 84%.
Research of Surface Generation Mechanisms in Single-Point Diamond Turning
Authors: Cheung Chi Fai , Lee Wing Bun , To Suet , Kong Ling Bao
Published: March 2009

One of the remarkable achievements of nanotechnology is the ability to achieve
nanometric surface finishes in single-point diamond turning of high-precision components for
complex optical surfaces. A better understanding of the surface generation mechanisms is of prime
importance for the development for the prediction of the surface roughness. This paper presents a
study of mechanisms of nano-surface generation in single-point diamond turning of various types of
materials.