bluuebunny/crossref_metadata_2025 huggingface dataset:
A Novel Biomineral Water Based Dental Cement
Authors: Engqvist Hakan , Kraft Lars , Spengler Håkan , Hermansson Leif
Published: March 2009

The area of cements in dentistry is steadily growing with the introduction of new
systems that need to be cemented to the tooth, e.g. new inlays and crowns. With the better properties of the implants there is a need for new cements with high bond strength, good esthetic and mechanical properties. The bioactive minerals have not been explored as dental cement. This paper investigates the strength, setting time and film thickness of a novel dental cement based on the biomineral Marokite (calcium aluminate) as bonding system. The reactive Marokite powder is mixed with glass filler (ratio of 1.9 by volume) and water (ratio of 0.4 by weight) to a paste, which hardens within 6 minutes and has a working time of 2 minutes. The compressive strength reaches 143 MPa after 24 hours and the flexural strength almost 40 MPa. When the film thickness is measured at the end of the working time
it is about 50 µm. Compared to glass ionomer cement (Fuji Cem) and zinc phosphate cement (Harvad) the biomineral system has higher strength and comparable setting time and film thickness.
The investigation shows that it is feasible to develop dental cements based on
biominerals, in this case a Marokite based material. The cement complies with the given standards.
Analysis of the Resorption of Calcium Phosphate Cement by Using High-Resolution X-Ray 3-D CT
Authors: Mukaida Masashi , Neo Masashi , Mizuta Y. , Ikeda Yasushi , Nakamura Takashi
Published: March 2009

High resolution X-ray CT is a powerful means for analyzing comprehensive ceramic
biomaterials in a living body. The benefit of this method is that morphological and volume changes of implant materials can be evaluated without retrieve of the implant in an animal body, resulting in no killing of the animals and long term evaluation even more than one year. In this study, in situ techniques for observation of calcium phosphate cement is developed. Calcium phosphate cement (CPC) was implanted into a femur and under skin of a rat. The volume and morphology change of the CPC were repeatedly measured using the same rat for more than 12 months.
The 3-dimentional (3-D) structures of the CPC were imaged and reconstructed from hundreds of 2-D cross sectional CT images, which were obtained at one time by a 360 degree rotation of the sample. The structure of the CPC was visualized with 3-D, and the volume were numerically analyzed by using a 3-D structure analyzing computer software, which enabled two-value processing and estimation of the quantities of the CPC. Moreover some of the CPC samples were retrieved and were observed by SEM. In the results, the surface of the calcium phosphate cement changed from smooth to jagged with increasing implanted period. The CPC volume implanted into bone was gradually decreased with increasing implanted period. The volume loss was 8 % after 12 months. The CPC volume under skin after 1 month increased by 7 %. After that the volume gradually decreased in next 3 months.
Absorption process of CPC in a rat will be discussed.
Injectability of a Macroporous Calcium Phosphate Cement
Authors: Delgado J.A. , Harr I. , Almirall Amisel , del Valle Sergio , Planell Josep A. , Ginebra M.P.
Published: March 2009

In this work an injectable and self setting calcium phosphate/albumen foam is developed. The effect of both the amount of albumen and the particle size of the starting a-tricalcium phosphate (a-TCP) powder on the injectability of the cement paste is studied. X-ray diffraction (XRD) and infrared (IR) analysis of the samples reveal that the hydrolysis of a-TCP to calcium deficient hydroxyapatite (CDHA) is not affected by the addition of albumen. A foamed structure formed by spherical pores with diameters between 100 and 500 µm is observed by SEM. This
porous structure is maintained after injection of the paste, although some deformation of the pores is produced due to the extrusion process. The injectability of the cements is increased by the presence of albumen as compared with cements prepared in the same conditions but without foaming agent.
Dissolution Studies of Silicon Containing Self Setting Bone Cement
Authors: Song Hee , Kim Soo Ryong , Jung S.J. , Lee J.K. , Kim Hee Joong , Kim Y.
Published: March 2009

Silicon containing self setting bone cement has been prepared by adding silicon
containing hydroxyapatite whisker to obtain a biomaterial having an improved resorption properties. Silicon containing calcium phosphate bone cement was composed of a-TCP: TeCP: DCPD: Si-HA whisker with a NH4H2PO4 as a setting liquid. From the XRD analysis, it was confirmed that calcium deficient hydroxyapatite phase appeared when it immersed in PBS solution. The dissolution rate of silicon containing calcium phosphate cement was measured in PBS solution and showed
high dissolution rate. Based on in-vivo test, silicon containing self setting bone cement can be considered a useful material for bone bonding materials.
The Bone Reaction to Ceramic Coated Pins - Animal Study
Authors: Bernstein Anke , Brandt Joerg , Gildenhaar Renate , Berger Georg , Hein W.
Published: March 2009

The reaction of animal bone to Ti6Al4V pins coated with ceramics of Ca2KNa(PO4)2 or Ca10[K/Na](PO4)7 as main crystalline phases were tested. It is shown that the new materials possess a very high resorption in comparison with hydroxyapatite (HA).
Crystallization of Sputtered Hydroxyapatite Films by Hydrothermal Technique and Its Cytotoxicity
Authors: Ozeki K. , Aoki Hideyuki , Fukui Y.
Published: March 2009

Hydroxyapatite (HA) was coated onto titanium substrates using radio frequency sputtering, and the coated HA films were crystallized in an autoclave at 110 °C using a low temperature hydrothermal method. The crystallinity, the Ca/P ratio, and the surface of the films were observed using XRD, EDS, and SEM, respectively. From the XRD patterns, a sputtered film after the hydrothermal treatment had crystallized after 24 h, and the Ca/P ratio decreased from 2.43 ± 0.07 to
1.75 ± 0.11. The growth rate of osteoblast cells was used for cell culture. Among control, titanium and hydrothermally treated film, there was no significant difference in the cell growth rate. However, the growth rate was suppressed on the as-sputtered film.
The Effect of Microporous Structure on Bone-Bonding Ability of Titanium
Authors: Cao Y. , Wang Li Ping , Zhang Bo , Lin Qiang , Li Xu Dong , Bao C.Y. , Chen Ji Yong , Yang L. , Zhang Xing Dong
Published: March 2009

The three different structures of titanium oxide film were prepared: (1) The commercial pure titanium was treated with heating in air at 700°C for half hour and gotten a dense rutile film on titanium (HS Samples); (2) The commercial pure titanium was treated by chemically treating and gotten a layer of amorphous titania gel on the Ti surface (TS Samples); (3) After chemically treating, the samples were heated in air at 700 °C for half hour, and gotten nano-particles coalesced
microporous titanium oxide (rutile) film on titanium surface (XS sample). The dense rutile and amorphous titania gel did not induce apatite formation on their surfaces in SBF solution for 48 hours, whereas the nano-particles coalesced microporous rutile structure induced apatite formation on their surfaces. Mechanical test and histological examination were investigated after the samples implanted in dogs limbs for 3 months. The results of push-out test are 12.96, 29.48 and 35.83 MPa respectively for HS, TS and XS sample. Histological results showed that TS sample and XS sample contacted the bone directly, without any intervening fibrous tissue, and there was a fibrous tissue layer between the bone and HS samples.
In Vitro Apatite Formation on Surface-Modified Titanium Coatings Prepared by Reactive Plasma Spraying
Authors: Inagaki Masahiko , Yokogawa Yoshiyuki , Kameyama Tetsuya
Published: March 2009

In vitro nucleation of apatite was studied over surface-modified Ti coatings prepared by reactive plasma spraying (RPS). An in-situ surface-modification of Ti particles is conducted by making use of plasma-enhanced reactions between the Ti particles and the reactive gaseous species in the plasma flame during plasma spraying. Surface-modified Ti coatings were deposited on Ti substrates by radio-frequency (rf)-RPS using a thermal plasma of Ar gas containing 1-6% N2 and/or
1-6% O2 at an input power of 16 kW. As a means of surface modification, Ti powders impregnated with 0.05-0.2 mol% Ca were also sprayed. Compositional changes in the coatings' surface after soaking in simulated body fluid (SBF) were examined by Fourier transform infrared spectroscopy (FT-IR) and thin film X-ray diffraction (TF-XRD). The Ti coatings prepared with Ar-O2 and Ar-N2-O2 plasma formed apatite after 3 days of soaking in SBF. On the other hand, no compositional
change was observed in the surface of the Ti coatings sprayed with Ar-N2 plasma, even after 7 days of soaking in SBF. In SBF tests, we observed a retardation of apatite deposition for the Ca-added Ti coatings prepared with Ar-O2 and Ar-N2-O2 plasmas. Analyses by X-ray photoelectron spectroscopy indicated that the Ca impregnated in the RPS-Ti coatings formed a Ca-O compound.
Oxidation of Titanium in Alpha-Calf Serum Solution
Authors: Ismailoglu Ali Sait , Li Pan Jian , Yang Xiaofan , Ari-Gur Pnina
Published: March 2009

Ti-6Al-4V polished disks were immersed in a-calf-serum-solution and studied for
resulting surface changes. The as-polished samples had more Ti2O3 close to the surface than titanium oxidizing in air – a result of low oxygen supply during polishing. Close to the interface with the metal, the TiO oxide is dominant. Immersion in serum caused the oxide thickness to become thicker, and to contain a higher concentration of the TiO2 component.
Whitening and Deodorization Ability by Peroxide and Hydroxyapatite Compound
Authors: Janurudin Juliana M. , Ozeki K. , Fukui Y. , Aoki Hideyuki
Published: March 2009

In this paper, a low concentration of Hydrogen Peroxide (H2O2) was added to the hydroxyapatite ceramics to develop HA/H2O2 compound. The HA/H2O2 was tested for the whitening and deodorizing ability. HA/H2O2 composite was added with glycerin and was tested on the enamel layer for lightness changes on the tooth layer. The lightness result was compared with 100[ppm] of H2O2 treatment by
Spectro Color Meter and enamel layers structure observation by optical microscope. In deodorization test, 20[g] of clove garlic and slice garlic were identified for garlic aroma peak. 20[g] of HA/H2O2 compound, HA alone and charcoal respectively were tested for the garlic aroma adsorption ability.
Identification and quantification of the garlic aroma peak area decrease was observed by gas chromatography. In the whitening result, HA/H2O2 compound and H2O2 alone treatment obtained 68 and 67 respectively. From the structure observation, HA/H2O2 composite treatment was the best since the smooth and unharmed enamel layer of the tooth was observed. Deodorization ability for HA/H2O2 compound has the similarity rate as charcoal at 82.3[%]. The HA/H2O2 composite has an ability of whitening and deodorizing at even low concentration.
Preparation of Porous Biphasic Tricalcium Phosphate and Its In Vivo Behavior
Authors: Kamitakahara Masanobu , Ohtsuki Chikara , Oishi M. , Ogata Shinichi , Miyazaki Toshiki , Tanihara Masao
Published: March 2009

Biphasic ceramic consisting of tricalcium phosphate with α- and β -phases (αβ-TCP) is a candidate as biodegradable bone substitutes since its biodegradability may be controlled by the ratio of the phases. In the present study, preparation of porous αβ-TCP body with continuous pores of 10-50 µm in diameter was attempted using additives of Mg, and its in vivo behavior was examined. Powder of β-TCP was mixed with Mg and potato starch to form slurry, followed by loading in polyurethane foam. The sample was fired at 1400°C for 12 hours for sintering process. α-TCP
content of the sample decreased with increasing the Mg content, while β-TCP increased. Ceramic body consisting of β-TCP phase was obtained when 1.0 mass% of Mg was added. Porosity of the body decreased with increasing the content of Mg. The αβ-TCP body with 80% porosity was obtained when the content of Mg was 0.1 mass%. The in vivo experiments showed that the rate of
degradation of the obtained αβ-TCP was almost same as α-TCP, and much higher than β-TCP.
Effect of Microstructure on Osteoinductivity of Biomaterials
Authors: Chen Ji Yong , Duan You Rong , Zhang Xing Dong
Published: March 2009

Two sets of porous biphasic calcium phosphate ceramics (BCP) were prepared for dynamic SBF experiment: porous BCP with micropores on the walls of macropores( set A) and porous BCP with dense walls of macropores (set B). Apatite layer could only formed on the macropore walls with micropores. Four groups of specimens were prepared for animal experiments.
Group A was porous BCP ceramics with micropores on the walls of macropores; group B was porous BCP with dense walls of macropores; group C was porous BCP ceramics with apatite layers formed by static SBF[2]on their surfaces; group D was porous BCP ceramics with apatite layers formed by dynamic SBF on their walls of macropores. The result of dynamic SBF animal experiments showed that microstructure of BCP played an important role in the bone-like apatite formation and
osteoinductiion in biomaterials. Apatite formation may be the prerequisite of osteoinductive formation of new bone.
Method for Tailoring and Control the Morphology, Size and Porosity of Calcium Phosphate Granules
Authors: Lemos A.F. , Rocha J.H.G. , Ventura J.M. , Ferreira José Maria F.
Published: March 2009

Hydroxyapatite (HA) is the calcium-phosphate material with composition closest to that of human bone, what makes it suitable for osseous implant purposes, namely as fillers, spacers and bone grafts substitutes. This study is aimed at the development of a method to produce porous spherical hydroxyapatite granules. The process involves the spraying of a suspension with different amounts of a setting agent to a setting media. The tailor and the control of the morphology, size and
porosity of the granules were attained by adjusting the nozzle diameter, the pressure of air flow and the distance between the nozzle and the setting media.
Surface Modification of Calcium Hydroxyfluor Carbonate Apatites by Bisphosphonates
Authors: Rodríguez-Lorenzo Luis M. , Vázquez Blanca , San Román Julio
Published: March 2009

Hydroxyapatite has been frequently described as an osteoconductive but not
osteoinductive material based on failure to observe bone formation in nonbony sites.
Bisphosphonates (BPs) are stable pyrophosphate analogs, that enhance the proliferation, differentiation and bone forming activity of osteoblasts and are potent inhibitors of bone resorption.
In this paper, the modification of a calcium hydroxyfluor carbonate apatite with sodium alendronate and (4-(aminomethyl)benzene)bisphosphonic acid is described. The surface modification is carried out by refluxing the apatite in a bisphosphonate acetone solution. Modified particles are characterized by thermal analysis, ATR-IR spectroscopy and contact angle between other techniques. A weight loss between 150 and 500°C can be observed for the modified apatites. IR
spectra show the appearance of bisphosphonate bands on modified powders. The surface energy of the modified apatite is reduced up to a 74% from the total apatite value after the alendronate surface modification with a decrease of 58% of the polar component main responsible of the cellular interaction of biomaterials.
Preparation of Biodegradable Porous Calcium Metaphosphate Granules as Bone Filler by Starch Consolidation
Authors: Yang D.J. , You Chang Kuk , Kim J.W. , Kim T.H. , Shin Hong In , Kim Kyo Han , Lee J.H. , Kim Suk Young
Published: March 2009

Porous calcium metaphosphate granules for bone fillers were prepared by starch
consolidation with baking powder and surfactant. Paste for foaming was prepared by the mixing of calcium metaphosphate powder and water with the various amount of starch (10~20㎛ size), where solid contents 30%, 45%, 60% of the paste. In order to obtain the optimum micro/macro porous structure, the appropriate contents of baking powder and surfactant at a fixed content of starch were
examined. In order to examine the content of baking powder on pore morphology, the baking powder was added 60, 180, and 300 wt% of the paste at fixed content of starch. And then, in order to investigate the effect of surfactant on porous structure, surfactant was added 0.035, 0.1, and 0.16 wt% of paste weight at fixed content of starch and baking powder. Foaming was conducted using microwave method, and foamed samples were sintered at 900 °C. The sintered porous blocks with
starch only showed uneven and closed macro pores without any micro pores. However, the sintered porous blocks with starch, baking powder, and surfactant showed homogeneous micro and macro porous structures ranging 20~60, and 300~1000 ㎛ in pore size, respectively. The porosity was increased with the increase of surfactant up to about 70 %.
Fabrication of Carbonate Apatite Form and its Basic Properties
Authors: Kunio Ishikawa , Udoh Koh-ichi , Wakae Hanae , Munar Melvin L. , Matsuya Shigeki , Nakagawa Masaharu , Nakajima Akihiko
Published: March 2009

Carbonate apatite form that has three-dimensional fully interconnected pore was prepared based on so-called ceramics form preparation method. First, a-tricalcium phosphate (a-TCP) form was prepared by immersing polyurethane form into a-TCP powder suspension. The form was heated in an electronic furnace for sintering a-TCP as well as for burning out of the polyurethane form. Then hydrothermal treatment was preformed at 200 degrees in the presence of saturated sodium
bicarbonate for 24 hours. Although the mechanical strength of the carbonate apatite form was poorer when compared with a-TCP form, we found that the hydrothermal treatment of a -TCP form result in the formation of B-type carbonate apatite form without changing the ideal morphology of a -TCP form.
A Novel Drug Delivery System for Bisphosphonates: Innovative Strategy for Local Treatment of Bone Resorption
Authors: Josse S. , Faucheux C. , Soueidan A. , Grimandi G. , Massiot D. , Alonso B. , Janvier Pascal , Laïb S , Guicheux Jerome , Bujoli B. , Bouler Jean Michel
Published: March 2009

One type of potent aminobisphosphonate (Zoledronate) has been chemically
associated onto b-tricalcium phosphate [b-TCP] and calcium deficients apatite [CDA]. Two different association modes have been observed, according to the nature of the Calcium Phosphate [CaP] support and/or the initial concentration of the Zoledronate solution. b-TCP appears to promote Zoledronate-containing crystals formation. On the other hand, at concentrations < 0.05 mol.L-1 CDA seems to undergo chemisorption of the drug through a surface adsorption process, due to PO3 for PO4 exchange, which is well described by Freundlich equations. At concentrations > 0.05 mol.L-1, crystalline needles of a Zoledronate complex form onto the CDA surface. The ability of CDA to release Zoledronate, resulting in
the inhibition of osteoclastic activity, was shown using a specific in vitro bone resorption model.
Protein Adsorption Property of a Biomimetic Apatite Coating
Authors: Wen Hai Bo , Hippensteel Elizabeth A. , Li Pan Jian
Published: March 2009

Hydroxyapatite (HA) coating applied on metallic orthopedic joint implants can improve bone apposition, presumably through selective protein adsorption from blood plasma. However, the detailed interaction mechanism of HA coating with serum proteins remains to be largely elucidated. Protein adsorption behavior of a biomimetic apatite (BAp) coating in bovine calf serum and alpha calf fraction was investigated in this study. Plasma sprayed HA (PSHA) coating was tested in alpha calf fraction. The microstructure and composition of the coatings before and after serum incubation were characterized and the proteins adsorbed during the incubation were extracted from the coatings and analyzed. Microstructural transformation of the BAp coating accompanied by selective serum protein adsorption was observed after incubation in both media. The total protein amount
adsorbed by the BAp coating in alpha calf faction was about three times that of the PSHA coating. To test the potential use of BAp coating as a carrier of therapeutic agents, interaction between the BAp coating and transforming growth factor (TGF)-β1 was studied. The growth factor was successfully loaded onto the coating in a sodium acetate buffer. Because of its high affinity to the coating, TGF-β1 could not be easily eluted in a bovine serum albumin containing solution but could
be recovered after coating dissolution in acid. The strong protein adsorption property of the BAp coating was found to be due mainly to its unique nanoporous structure. The BAp coating can serve as an ideal carrier of therapeutic agents for aiding in the healing of bone and soft tissues.
Antimicrobial Treatment of Dental Osseous Defects with Silver Doped Bioglass: Osteoblast Cell Response
Authors: Lohbauer U. , Jell G. , Saravanapavan Priya , Jones Julian R. , Hench Larry L.
Published: March 2009

In dentistry, chronic periodontitis often leads to bone resorption together with an increasing risk of bacteremia. Bioactive glass has found extensive application as dental graft material. A successful antimicrobial bactericidal effect has been shown from the introduction of Ag2O into the glass composition. In this study, the cytotoxicity of soluble silver, calcium and silica ions on primary human osteoblasts was investigated by measurements of mitochondrial activity and neutral red dye uptake. Silver concentrations of 4 - 6 ppm (1 mg/ml conc.) and 6 - 9 ppm (2 mg/ml conc.) have been measured in complete culture medium. It was found that the bioactive gel-glass extract with an initial concentration of 1 mg/ml (1mg glass per ml of culture medium) has no negative effect, whereas increased gel-glass concentration of 2 mg/ml seemed to have a toxic effect on the cell viability of human osteoblasts. It might be concluded that a reduction of the rate of silver dissolution from the bioactive gel-glass might preserve a maximum cell viability.
In Vitro Analysis of Protein Adhesion to Phase Pure Hydroxyapatite and Silicon Substituted Hydroxyapatite
Authors: Botelho C.M. , Brooks Roger A. , Kawai Takahiro , Ogata Shinichi , Ohtsuki Chikara , Best Serena , Lopes M.A. , Santos José D. , Rushton Neil , Bonfield William
Published: March 2009

The adhesion of bovine collagen type I, bovine serum albumin, bovine IgG, 1 % and 10 % (v/v) human serum to hydroxyapatite (HA), silicon-substituted hydroxyapatite (Si-HA) and tissue culture plastic were studied. The materials were incubated at 37 °C for 30 minutes, after which the protein solution was removed and analyzed. The adsorbed protein was evaluated by electrophoresis and immunoassay after extraction from the materials. The degree of adhesion was
higher for collagen, followed by IgG and albumin on all materials. However there was no difference in the amount of collagen adsorbed onto the surface of each material and this was also the finding with albumin and IgG. These results suggest that the increased bioactivity seen with Si-HA is not due to the degree of protein adhesion, but may possibly be due to changes in the conformation of the bound proteins.
Transformation of Electrodeposited Calcium Phosphate Coatings in Simulated Body Fluid and in Culture Medium
Authors: Park Ji Ho , Lee Yong Keun , Kim Kwang Mahn , Kim Kyoung Nam
Published: March 2009

The coatings formed on the H2O2-treated titanium substrate by electrodeposition were used in order to evaluate the difference of transformations in the simulated body fluid (SBF) and the culture medium with MG63 cells. A porous hydroxyapatite (HA) coating with relatively low crystallinity and large crystallites was formed on the H2O2-treated titanium substrate by electrodeposition. HA coating
transformed for 5 days in the SBF consisted of densely-packed rod-shaped crystallites with various differentiated grains. Octacalcium phosphate (OCP) and HA coating transformed for 5 days in the culture medium consisted of both flake-shaped and rod-shaped crystallites with indistinct grains. MG-63 cells were well attached and proliferated during the transformation into this flaked-shaped OCP. This difference between transformations of the HA coatings in the acellular SBF and in the culture medium with MG63 cells is due to different ion composition in each solution and proteins in culture medium.
Formation of Hydroxycarbonate Apatite Layer on Poly(Lactic Acid) Composites in Simulated Body Fluid
Authors: Maeda Hirotaka , Kasuga Toshihiro , Nogami Masayuki
Published: March 2009

Hydroxycarbonate apatite (HCA), which formed on a poly(lactic acid) (PLA) composite membrane containing vaterite or calcium chloride after soaking in simulated body fluid, was examined to clarify the importance of the ceramic phases in the composites. FT-IR spectra showed that the ratio of CO3/PO4 in the infrared adsorption bands of HCA formed on the PLA composite containing vaterite was much larger than that of HCA formed on the PLA composite containing
calcium chloride. Substitution of carbonate ion in hydroxyapatite is believed to be strongly influenced by ceramic phases in the composites. The zeta potentials of HCA formed on the PLA composite containing vaterite or calcium chloride was -6 mV or -17 mV, respectively. The zeta potential may be influenced by the amount of carbonate ion in hydroxyapatite.
Effect of Operation Conditions on HA Synthesized by the Hydrothermal Method
Authors: Kothapalli Chandrasekhar , Wei Mei , Shaw Montgomery T.
Published: March 2009

This paper reports the influence of aging time and reaction temperature on the surface morphology and mechanical properties of hydroxyapatite (HA) synthesized by a hydrothermal method. Calcium nitrate and ammonium orthophosphate solutions were premixed and fed to an autoclave and reacted to temperatures varying between 25-250°C for 2-10 h. Results indicate the strong positive influence of reaction temperature on the HA particle aspect ratio. The density of the discs pressed from these samples reached 85-90% of the theoretical density after calcination at 1200°C for 1 h. Sintered density and flexural strength were found to increase with increasing aging time and reaction temperature. A maximum flexural strength of 78 MPa was observed for the sample synthesized at 170°C for 5 h with the predicted average at these conditions being 65 MPa.
A Bio-Photonics System for Rapid In Vitro Testing of Cells and Ceramics
Authors: Hench Larry L. , Notingher Ioan
Published: March 2009

We present a new bio-photonic method based on Raman spectroscopy able to
characterize living cells in in-vitro cultures. The main advantages of this technology are: no labels or other contrast enhancers are required; provides real-time analysis; cells can be maintained in physiological conditions during the measurements; no cell-damage is induced during the measurements; it is rich in information about the biochemical composition of the cell. The results show that this spectroscopic method can be used to study the most important cellular functions involved in cell-biomaterial interactions, such as cell death, differentiation, de-differentiation and
mineralization. The method offers the potential for studying cell-bioceramics interaction and reduce the need of animal testing until the final steps of proving efficacy prior to clinical trials.
Influence of Emdogain® Treatment onto K2O Incorporated Calcium Metaphosphate on Osteogenic Activation
Authors: Kim Suk Young , You Chang Kuk , Jeong Jae Ho , Park Eui Kyun , Kim Shin Yoon , Shin Hong In
Published: March 2009

As a part of the efforts to develop a suitable scaffold optimizing bone regeneration that has similar physical properties to bone, we modified calcium metaphosphate (CMP) ceramics with K2O and evaluated their efficiency as a scaffold for tissue engineered bone tissue regeneration. Macroporous CMP ceramics modified by incorporation of 5% K2O to improve biodegradability were prepared to have 250 and 450 µm average pore sizes, respectively. The modified CMP ceramics were
cultured with mouse primary calvarial osteoblastic cells in osteogenic media for 2 weeks and these cell-CMP ceramic constructs with or without Emdogain treatment were implanted in the SCID mice subcutaneous pouches. After 1, 2, and 3 weeks, the degree of ectopic bone formation was evaluated. The modified macroporous CMP ceramic-cell constructs treated with Emdogain induced ectopic
bone formation, whereas the modified CMP ceramic-cell constructs without Emdogain treatment induced no ectopic bone formation. This result suggests that the Emdogain treatment on cell-scaffold constructs for tissue engineered bone regeneration may be effective for osteogenic activation of attached cells.
Evaluation of Osteoblast Viability, Alkaline Phosphatase Production and Collagen Secretion in the Presence of Hydroxyapatite Reinforced with Oxide Glasses
Authors: Sampaio B.V. , Göller G. , Oktar Faik Nuzhet , Valério Patricia , Goes Alfredo , Leite M. Fatima
Published: March 2009

Two (45.5 wt % P2O5, 54.5 wt% CaO) and three (45 wt % P2O5, 28 wt%
CaO, 27wt% Na2O) oxide glasses, sinterizing at 1200 and 1300oC[2] showed an
increase on cell viability and proliferation.
Osteogenic Potential of Estriol-Treated Cultured Bone - In Vitro and In Vivo -
Authors: Iida Jin , Yoshikawa Takafumi , Miyazaki Kazuhide , Okumura Noriko , Takakura Yoshinori
Published: March 2009

Osseous tissue can be formed by culturing marrow cells with compounds such as
dexamethasone and that a bone matrix cultured in this manner possesses BMP activity. We have reported that artificial bones with a high level of osteogenic potential can be prepared by culturing artificial bone materials with cultured osseous tissue. Here, in an attempt to develop activated cultured bone constructs with even greater osteogenic potential, the effects of the female hormone estriol on osteogenesis were investigated. Bone marrow cells were collected from the femur shafts of 7-week-old male Fischer rats, and subjected to primary and secondary cultures. During secondary culture with or without dexamethasone (Dx), 10-5, 10-6, 10-7, 10-8 or 10-9 M of estriol was added to a standard culture medium containing ascorbic acid and β-glycerophosphosphate. The alkaline phosphatase(ALP) activity and Ca levels were measured and statistically analyzed. There was a significant difference in ALP activity between the control group and the estriol groups, and ALP activity was the highest in the 10-7 and 10-8 M groups, being about 2.5 times higher than in the control group. Similar results were seen for Ca levels. Furthermore, in vivo study showed10-7M-estriol-treated-cultured bone/ceramic construct has significant high osteogenic potential when it is grafted into in vivo. Estriol has been reported to increase bone mass, and the results of the present study suggest that the osteogenic potential of cultured bone constructs can be more than doubled by adjusting the concentration of estriol in bone marrow cell culture. Therefore, the use of estriol may be able to facilitate osteogenesis in bone regeneration therapy.
Osteogenic Effect of Genistein on In Vitro Bone Formation by Human Bone Marrow Cell Culture - For Development of Advanced Bio-Artificial Bone
Authors: Okumura Noriko , Yoshikawa Takafumi , Iida Jin , Nonomura Akitaka , Takakura Yoshinori
Published: March 2009

The effect of genistein, a soybean isoflavone, on new bone formation by bone marrow cells from mature humans was examined. After informed consent was obtained from a 55-year-old woman with osteoporosis and lumbar spondylosis deformans，bone marrow cells were collected from her ilium, cultured in the standard medium of MEM containing fetal calf serum and then cultured with or
without the addition of genistein to the bone-forming medium containing dexamethasone etc.． In humans, when genistein was added to the bone-forming medium, genistein (10-7 M and 10-8 M)caused a significant increase in the levels of alkaline phosphatase avtivity and DNA content compared with cells not cultured in genistein． In conclusion，genistein was found to promote bone formation at lower concentrations，and thus may be useful as a bone formation-promoting factor.
Tensile and Compressive Behaviours and Properties of a Bone Analogue Biomaterial
Authors: Wang Min , Au C.L. , Lai P.K. , Bonfield William
Published: March 2009

For the purpose of mimicking the structure and matching mechanical properties of human cortical bone, a natural composite material, hydroxyapatite (HA) reinforced high density polyethylene (HDPE) has been developed as a bioactive, analogue material for bone replacement. This synthetic composite material is now in clinical use. To understand the deformation behaviour and determine mechanical properties of HA/HDPE composite under different loading modes and loading conditions, tensile and compression tests were performed in the current investigation. It was observed that under tension, HA/HDPE composite exhibited two types of deformation behaviour: ductile and brittle. Under compression, the composite deformed in a ductile manner and did not fracture at high compressive strains. It was found that an increase in HA content resulted in increases in Young’s modulus, compressive modulus, tensile strength and compressive yield
strength of the composite. A higher strain rate led to higher modulus and strength values and lower tensile fracture strains of the composite.
The Influence of Sintering Temperature on the Properties of Composites of Biologic Hydroxyapatite and Zirconia
Authors: Oktar Faik Nuzhet , Genc Yasin , Göller G. , Agathopoulos Simeon , Tulyaganov D.U. , Ferreira José Maria F. , Kayali E.S. , Salman S.
Published: March 2009

Bovine derived hydroxyapatite was doped with partially stabilized zirconia with 3 mol% yttria. The influence of sintering temperature and the amount of the incorporated zirconia on densification, mechanical properties, crystalline structure and microstructure was investigated. The results indicate that the produced materials exhibit poorer mechanical properties than the relevant composite materials of enamel derived hydroxyapatite. This difference can be attributed to F, since
F-content in bone is much higher than in enamel. Hence, in the light of the prospective use of the investigated materials in biomedicine, bovine derived hydroxyapatite doped with zirconia can potentially serve as graft material for load bearing applications if very small amount of F can be incorporated, in order to resemble the composition of enamel derived apatite.
Electrically Controllable Biomimetic Actuators Made with Multiwalled Carbon Nanotube(MWNT) Loaded Ionomeric Nanocomposites
Authors: Lee Deuk Yong , Heo Seok , Kim Kwang Jin , Kim D. , Lee Myung Hyun , Lee Se Jong
Published: March 2009

Biomimetic actuators that can produce soft-actuation but large force generation capability are of interest. Nafion, an effective ionomeric material from DuPont, has been shown to produce large deformation under low electric fields (<10V/mm). This response is caused by a direct electro-osmotic effect due to the existence and mobility of cations and subsequent swelling and deswelling of the material. In this effort, multiwalled carbon nanotube (MWNT)/Nafion nanocomposites were prepared by a casting in order to investigate the effect of MWNT loading in the range of 0 to 7 wt% on electromechanical properties of the MWNT/Nafion nanocomposites. The measured elastic modulus and actuation force of the MWNT/Nafion nanocomposites are drastically different, showing larger elastic modulus and improved electromechanical coupling, from the one without MWNT, implying that the effective MWNT loading is crucial to develop high-performance biomimetic actuators.
Mechanical Property Aspects of a Biomineral Based Dental Restorative System
Authors: Lööf Jesper , Engqvist Hakan , Gómez-Ortega Gunilla , Spengler Håkan , Ahnfelt Nils Otto , Hermansson Leif
Published: March 2009

A two component, capsule mixed dental restorative system based on a biomineral has been developed. After mixing the two components the material is to be regarded as a chemically bonded ceramic (CBC). In this work some basic mechanical properties has been evaluated and compared to high strength glass ionomer cement (GIC) and an amalgam. In addition the microstructure and fractured surfaces of the material has been investigated. The strength measurements show that the CBC material have comparable initial strength to an amalgam as measured by DTS. The flexural and the compressive strength of the fully hardened CBC material are comparable with a high strength GIC. The setting time showed to be easily
adjustable and a final setting under 6 minutes can be reached. The microstructure of the CBC material shows that all components have been fully dispersed resulting in a homogenous microstructure. When looking at the fracture surface of tested DTS samples of the CBC material a “pull-out” effect was revealed originating from the fibres added to the composition to increase the strength.
Biocompatibility of Diamond-Like Carbon Coated NiTi Orthodontic Wire and Acrylic Resin Teeth
Authors: Kobayashi S. , Ozeki K. , Ohgoe Y. , Gei Li , Hirakuri K.K. , Aoki Hideyuki
Published: March 2009

A variety of dental devices such as orthodontics, artificial teeth are implanted in oral
cavity for long term. The implant coated with protective films, which can reduce corrosion and wear, may prevent the problems described above and extend the lifetime of implants to the benefit of the patients. Diamond-like carbon films have extreme hardness, low friction coefficients, chemical inertness, and high-corrosion resistance. Moreover, these properties make the good candidates as biocompatible coatings for dental devices. In this study, DLC films using the plasma CVD method
deposited on acrylic resin and orthodontic archwires have investigated to detect the Ni release from the wires and to estimate cell growth in E-MEM immersed acrylic plates. After 6 months, the concentration of the nickel release from DLC-coated wire and Non-coated wire was 150 [ppb] and 933 [ppb], respectively. Results indicated DLC films inhibit the release of these materials, and prevent degradation of these materials in the solution.
Preparation and Properties of Lanthanide Phosphates
Authors: Kijkowska Regina , LeGeros Racquel Z.
Published: March 2009

Lanthanide phosphates are known as slightly soluble salts with their solubility products ranging from 10-25 to 10-27. These phosphates can be obtained a) by precipitation from aqueous solutions of their salts using, for example, sodium or ammonium phosphates or b) by crystallization from boiling phosphoric acid solution. Application of crystallization in highly acidic solution instead of precipitation method yields highly crystalline solids of the composition of LnPO4.H2O
(Ln: La, Ce, Pr, Nd, Sm, Eu, Gd, Dy, Ho, Er, Tm, Yb, Lu and Y). This paper presents the effect of the acidity of the solution used for the crystallization process on crystallinity and morphology of EuPO4.H2O obtained: the higher the acidity of the solution the larger the crystals obtained. The morphology of the crystals changed from sphere-like particles crystallized in 2M H3PO4 to large hexagonal rods formed 2M H3PO4 with additional 0.4 M of HCl or HNO3.
Bioactivity of the Two Kinds of Biodegradable Composite Membrane Containing Oriented Needle-Like Apatite
Authors: Itoh Toshiki , Ban Seiji , Watanabe T. , Tsuruta Shozo , Kawai Takahiro , Nakamura Hiroshi
Published: March 2009

It is well known that bone morphogenetic protein (BMP) induces bone formation and requires for carriers. Poly-lactic acid / poly-glycolic acid (PLGA) is frequently used as the carriers of BMP. We developed a biodegradable composite PLGA membrane, which was containing oriented needle-like apatite with BMP. The composite membranes were implanted into the thigh muscle pouch of 3-week-old-mice. At 3 weeks after implantation, the implanted area was observed by optical
microscopy. The composite membrane containing oriented needle-like apatite with BMP induced new bone formation. It seems that this composite membrane might be a scaffold of BMP and promoting the healing of bone defects.
In Vitro Cytotoxicity of Alginate-Encapsulating Ferrite Particles Using WST-1
Authors: Lee Sang Bae , Lee Se Ho , Kim D.H. , Lee Doug Youn , Lee Yong Keun , Kim Kyoung Nam , Kim Kwang Mahn
Published: March 2009

The purpose of this study was to evaluate the cytotoxicity of alginate-encapsulting ferrite particles in vitro. Various ferrite particles such as Ba-ferrite, Sr-ferrite, Co-ferrite, Co/Ni-ferrite were prepared by sol-gel process. Ferrite particles were encapsulated via calcium alginate process with different alginate contents ranged from 10 to 100 wt%. Mouse-fibroblastic NCTC L-929 cells were cultured in RPMI-1640 medium with 10% fetal bovine serum. The alginate-encapsulating ferrites
were extracted in 5 ml of distilled water under pH 6.5 at 121°C for 1 h in accordance with ISO 10993-12. In vitro cytotoxicity was evaluated by WST-1. The results of this study indicated that the alginate-encapsulting ferrite particles affected cell viability by increasing alginate contents. Especially, alginate-encapsulating process were enhanced cell viability of ferrites such as Sr-ferrite, Co/Ni-ferrite, and Ba-Ferrite when alginate content was 10 wt%.
Growth of Normal Human Osteoblast Cells on Hydroxyapatite/Titanium Alloy Composites Formed by Implantation of Hydroxyapatite Granules into Titanium Alloy
Authors: Watazu Akira , Oguchi H. , Yamada T. , Sonoda Tsutomu , Katou Kiyotaka , Nonami Toru , Saito Naobumi
Published: March 2009

On the hydroxyapatite/titanium alloy composite disks, the normal human osteoblast cells were cultured. As a result, the samples were covered with normal human osteoblast cells after 2 hours. Moreover, we did not observe cracks in any of the HA granules, and the normal human osteoblast cells extended between the HA granules and the titanium alloy. From these results, we have concluded that this material has good biocompatibility.
The Effect of Calcium Aluminate Bone Cement Incorporating LiF-Maleic Acid on the Bone Regeneration of 1-Wall Intrabony Defects in Beagle Dogs
Authors: Lee H.W. , Im S.U. , Song S.E. , Kim C.S. , Choi Se Young , Lee Yong Keun , Kim Kyoung Nam , Kim Chong Kwan , Choi Seong Ho
Published: March 2009

This study evaluated periodontal repair and biomaterial reaction following implantation of a newly fabricated calcium aluminate bony cement incorporating LiF-maleic acid on the regeneration of 1-wall intrabony defects in the beagle dogs. The surgical control group received a flap operation only, while the experimental group was treated with calcium aluminate bony cement incorporating LiF-maleic acid. The subjects were sacrificed 12 weeks after surgery and a comparative histologic
analysis was done. In the experimental group, the grafted calcium aluminate cement was not absorbed and fibrous connective tissue was epithelized around the particles of the grafted bony cement. Because of certain favorable properties, such as its easy manipulation and its ability to maintain the morphology of the defect site by acting as a scaffold, the newly developed cement is suitable for us as a graft material, and could be used very effectively in alveolar augmentation. However, further study needs to be conducted before it can be used as a bone graft material for periodontal tissue regeneration.
Erosion of Dental Glass Infiltrated Aluminum Ceramics
Authors: Yu Y.H. , Xiong F. , Zhu Z.M. , Liao Yun Mao , Zhou Zhong Rong
Published: March 2009

The erosion of dental glass infiltrated aluminum ceramics by sandblasting was evaluated. The variations of wear depth, surface roughness and bending strength after blasting were of particular interest. The sandblasting parameters of working pressures, times and erodent size came from routine manufacturing procedures. The results showed the erodent size affects the bending strength and pressure affects mainly the wear depth. The surface roughness increased significantly
after sandblasting, but the differentiations with various blasting parameters were not apparent. Fatigue cracking characterized the mechanisms of erosion of dental glass infiltrated ceramics.
Biomechanical, Radiomorphometric Evaluation of CaO-SiO2-B2O3 Glass-Ceramics in a Rabbit Lumbar Fusion Model
Authors: Lee Jae Hyup , Ryu Hyun Seung , Seo Jun Hyuk , Kim Hwan , Hong Kug Sun , Chang Bong-Soon , Lee Choon Ki
Published: March 2009

The purpose of our study is to compare the biodegradation and osteoconduction between CaO-SiO2-B2O3 glass-ceramics(CS10B) and hydroxyapatite(HA), tricalcium phosphate(TCP). Porous CS10B implants were prepared by polymer sponge method. Single-level posterolateral spinal fusions were performed on thirty rabbits. The animals were divided into three groups by implant material: HA, TCP and CS10B. Radiographs checked every two weeks. All animals were sacrificed
12 weeks after surgery. The proportion of the area occupied by ceramics in final radiography on the initial radiography was calculated. Uniaxial tensile strength was measured on 7 cases in each group. The proportion of the area of HA(88.7%±16.1) was significantly higher than those of the others(p<0.05), and the proportion of the area of CS10B(28.2%±9.3) was significantly lower than
those of HA and TCP(37%±9.6)(p<0.05). The mean values of tensile strength of the HA(191.4±33.5 N) and CS10B(182.7±19.9 N) were significantly higher(p<0.05) than those of the TCP(141.1±28.2 N). CS10B showed the tensile strength of fusion masses similar to those of the HA, however, more rapid biodegradation than HA and TCP. These findings suggest that CS10B grafts have the possibility as a bone graft substitute.
MoSi2 Ceramic Foam Prepared by Polymer Pyrolysis
Authors: Paek J.W. , Kim Beom Seob , Kim Deug Joong
Published: March 2009

Ceramic foams containing MoSi2 were prepared by a self-blowing process of poly-silsesquioxane with MoSi2 as filler. Ceramic foams prepared by polymer pyrolysis were composed of MoSi2 and silicon oxycarbide glass matrix. Densities, pore sizes and mechanical properties of ceramic foams were depended on the filler content and heating rate for curing of polymer. Depending on the foaming condition, ceramic foams with a density of 1.2∼0.4 and a compressive strength of 3∼30 MPa were obtained.
The Drug Delivery Application of Sponge Phased Silica Ceramic Structure
Authors: Chang Jeong Ho , Shim Chang Han , Kim Kyung Ja
Published: March 2009

This work describes an innovative approach to preparation of the highly controlled drug delivery materials that involves a self-assembly process at the molecular level based upon the silicified L3 phase silicates and thermoresponsive PNIPAm integrated L3 phase silicates. The materials designed by the integration of thermosensitive polymer have been prepared and demonstrated for the highly controlled drug releasing system over a longer period of time due to their high degree of continuity and contigunity in 3-D interconnected porous structure. This approach is suitable for long term drug delivery systems with constant release in hard tissue engineering due to nanodiffusion mechanism. The structural characterization was achieved by TEM, SEM, SAXD, solid-state 29Si NMR, and BET.
Effect of Grain Boundary Phase on Contact Damage Resistance of Silicon Nitride Ceramics
Authors: Lee Chul Seung , Lee Kee Sung , Lee Shi Woo , Kim Do Kyung
Published: March 2009

Contact damage resistances of silicon nitride ceramics with various grain boundary phases are investigated in this study. The grain boundary phases are controlled by the addition of different types of sintering additives, or the crystallization of intergranular phase in a silicon nitride. We control the microstructures of materials to have similar grain sizes and the same phases to each other. Contact testing with spherical indenters is used to characterize the damage response. The implication is that the grain boundary phase can be another controllable factor against contact damage and strength degradation even though it is not critical relative to the effect of grain morphology.