bluuebunny/crossref_metadata_2025 huggingface dataset:
Preliminary Results of In Vitro Study of Cell Growth in a 45S5 Bioactive Glass as Bone Substitute Using Scanning Electron and Confocal Microscopies
Authors: Maksoud Rami , Lefebvre Leila , Heinrich Laurence , Gremillard Laurent , Chevalier Jérôme , Hartmann D.J.
Published: March 2009

The aim of this study was to evaluate the cytocompatibility, cell ingrowth and extracellular matrix deposition of a newly developed porous bioactive glass as a bone substitute. Two types of bioactive glass, different in their pore size (75 and 20 ppi, resp. ~350 and ~1200 $m), were used in this study. The materials were seeded with human osteoblastic (MG63) and fibroblastic (M-228 F01 and M-191 F01) cell lines. The cells were visualized by two techniques, scanning electron microscopy and confocal microscopy. For confocal microscopy cell nuclei were labeled with propidium iodide (IP) and the extracellular matrix components (type I collagen and osteocalcin) by specific antibodies. Cells and matrix were visualized by fluorescence. The bioactive glass used in this study was shown to be non cytotoxic. Cell growth and colonization at the surface and in the depth of the material were observed. Extracellular matrix deposition was also demonstrated which proved the proper biofunctionality of the biomaterial. Scanning electron microscope allowed us to visualize cells at a high magnification at the surface of the bioglass and evidenced that the biomaterials were covered by a sheet of cells with their matrix; on the other hand, confocal microscopy permitted us to observe cell ingrowth and matrix deposition within the depth of the substitute. We showed that extracellular matrix was synthesized mainly in the upper levels where the cell population was the most confluent. In summary, this porous bioglass appears promising for bone substitution.
Antibacterial Activity of Silver-Doped Glasses and Glass-Ceramics
Authors: Verné Enrica , Miola Marta , Ferraris Sara
Published: March 2009

A glass (G) and a glass-ceramic (GC) of different composition were selected and studied
to realize a biocompatible e/o bioactive material with antibacterial properties through the
introduction of silver ions. The glass was produced in bulk form, instead glass-ceramic powders
were sintered to abtain massive samples, which are characterized in terms of biocompatibility and
subjected to ion- exchange technique [1] to allow the silver ions introduction and modify only the
external surface layer of the materials, thus maintaining unchanged the bulk characteristics. The
obtained samples were completely characterized to verify if the silver introduction leads to
structural, morphological or in vitro behaviour change; silver release test was also carried out as
well as antibacterial test with Staphylococcus Aureus and cytotoxicity test on human cells.
Macroporous Biphasic Calcium Phosphate Bioceramics Wedges in High Tibial Osteotomy
Authors: Rouvillain Jean Louis , Lavallé F. , Pascal-Mousselard Hugues , Catonné Yves , Delattre Olivier , Daculsi G.
Published: March 2009

In this study, we report human clinical and histological data on the use of micromacroporous biphasic calcium phosphate wedges in combination with osteosynthesis with adjustable screws for open tibial osteotomy. 42 patients were operated for open tibial osteotomy for valgisation due to incipient medial gonarthrosis. The population was composed of 43 knees (25 right knees and 18 left knees) in 13 women and 29 men, with a mean age of 46 years. Radiological follow-up at D+1, D+90 and D+360, and 12 biopsies for histology were processed after the removal of the osteosynthesis. Consolidation was obtained in 100 % of cases (except one, because of failure of the osteosynthesis). Regular bone ingrowth was observed on X-ray, with maintain of the corrections at one year in 98.5 % of cases. Only 8 % of cases showed a radiolucent interface after D+360. Histological examinations demonstrated resorption of the MBCP and large bone ingrowth. Polarised microscopy confirmed the lamellar bone, and the X-rays and microscanner revealed well mineralised and organised newly-formed bone.
A Retrospective Study on the Clinical Sucess Rate of OSSTEM Implant
Authors: Baik S.M. , Kim S.G.
Published: March 2009

This study analyzed the examination records and radiographs of 247 patients (144 male,
103 female) who received an OSSTEM Implant (Seoul, Republic of Korea) at the dental clinic at
Chosun University, Korea, between January 2002 and December 2005. The overall success rate in
patients who received an OSSTEM Implant from surgeons of the Department of Oral Surgery at our
hospital was 93.1%, making the overall failure rate relatively low (6.9%). The failure rate for the
maxillary molar tooth was slightly higher, at 9.95%, probably as a result of its relatively lower bone
quality and reduced osteoid volume caused by pneumatization of the maxillary sinus. Thus, to
determine appropriate treatment, it is necessary to accurately determine bone quality and volume.
This can be achieved with implant placement analysis of computed tomography, precise
preoperative planning, and sufficient technical experience.
Evaluation of Biocompatibility of Porous Hydroxyapatite Developed from Edible Cuttlefish Bone
Authors: Kim Jung Jae , Kim Hae Jung , Lee Kang Sik
Published: March 2009

A edible cuttlefish(Zoological name : Sepia esculenta) bone has a porous structure with
all pores interconnected The purpose of this research is to develop porous hydroxyapatite prepared
by hydrothermal treatment from cuttlefish bone and evaluate the biocompatibility using
undecalcified materials through the in-vivo test of rabbits. In this study, the phase and substructure
of a porous hydroxyapatite, prepared by hydrothermal treatment using edible cuttlefish bone as a
calcium source, has been confirmed by X-ray diffractometer and scanning electronic microscope.
After preparing the specimens with 5mm diameter and 7mm length, the specimens were implanted
into the femoral condyles of rabbits. Each rabbits were sacrificed at each time period of 1, 2, 3, 4
weeks after operation, respectively and the stained section was examined by a transmission light
microscope. The X-ray diffraction patterns of the edible cuttlefish bone was confirm for aragonite
phase and of the sample after hydrothermal treatment showed mostly into hydroxyapatite phase.
There was more bone density increase in porous HA rod around implant site than natural edible
cuttlefish bone. Because the edible cuttlefish bone is a very pure and good calcium source, porous
hydroxyapatite developed from this study is expected to be a biomaterial having a good
biocompatibility to be used as a suitable bone substitute.
The Effect of Particle Morphologies on Mechanical Properties of Porous Hydroxyapatite Scaffold
Authors: Zhao J. , Xiao S.G. , Wang Jian Xin , Weng Jie
Published: March 2009

Porous hydroxyapatite (HA) ceramic scaffolds are extensively used to induct the tissue growth for bone repair and replacement, and serve functions to support the adhesion, transfer, proliferation and differentiation of cells. Highly porous structure is always expected for its positive effect on the bone regeneration in vivo, nevertheless high porosity always accompanies a decrease in strength of the HA ceramic scaffolds. Therefore, it is significant to improve the strength of the HA ceramic scaffolds with highly interconnected porosity so that they are more suitable in clinic applications. The aim of this study is to investigate the effect of starting materials on mechanical property of final scaffold in order to optimize the preparation process. In this work, three starting HA particles with different morphologies are used to prepare highly porous HA ceramic scaffolds by the polymer impregnation approach in the same preparation process. The phase composition, microstructure and mechanical properties of the sintered porous HA scaffolds are investigated by x-ray diffraction (XRD), scanning electron microscopy (SEM) and compressive test. The experimental results show that the particle morphologies have influence on the slurry viscosity and further affect the coating amount on the sponge. The porous HA ceramics fabricated by spherical HA particle hold the highest compressive strength than the other two HA scaffolds for better sintering property. It is an effectively method to improve the mechanical property of porous HA ceramic scaffolds by optimizing the starting particle morphology.
Glass-Ceramic Scaffolds and Shock Waves Effect on Cells Migration
Authors: Vitale-Brovarone Chiara , Baino Francesco , Martinasso Germana , Canuto Rosangela , Bassi Francesco , Verné Enrica
Published: March 2009

Glass-ceramic scaffolds for bone grafting have been prepared using the sponge
replication method and a highly bioactive silica based glass belonging to the system SiO2-P2O5-
CaO-MgO-Na2O-K2O (CEL2). The parameters for the sponge impregnation were optimized in
order to obtain a continuous coating of the polymeric skeleton which will lead, after the polymeric
phase removal, to a resistant macroporous glass-ceramic template. A complete characterization was
carried out on the obtained scaffold in order to assess its morphology and specifically its porosity
and the degree of pores interconnection. A human osteoblasts cells line (MG-63) was cultured onto
the scaffold and the effect of stimulation with shock waves on the cell ability of colonizing the
scaffold was investigated.
Potential Applications of Glass and Glass-Ceramics Based on Lithium Disilicate as Biomaterials
Authors: Palou Martin , Bakoš Dušan , Kuzielová Eva , Labuda Ján
Published: March 2009

Lithium disilicate glass and glass with addition of P2O5, CaO and CaF2 (in relative ratios corresponding to 10 wt. % of „apparent fluoroapatite”) were prepared by quenching their melts obtained at 1400 °C. Then, the parent glasses were thermally treated at 550°C and 750°C to obtain glass ceramics. The bioactivity test in vitro and the Wicker hardness in relation to „apparent fluoroapatite“ presence and heat treatment were investigated. The presence of fluoroapatite in samples promotes mineralization of new phase apatite-like on the surface of glass and glass ceramics after 6-week immersion in SBF as proved by SEM and EPMA. The bioactivity decreases with thermal treatment of parent glass. However, whole surface of glass-ceramics was covered with apatite phase after long-term immersion in SBF. The Vickers hardness of samples increases with increasing temperature treatment and with the presence of fluoroapatite.
Comparative Study of In Situ Interactions between Maleic Anhydride Based Copolymers with Hydroxyl Apatite
Authors: Piticescu Roxana M. , Chitanu Gabrielle Charlotte , Meghea Aurelia , Giurginca Maria , Negroiu Gabriela , Popescu Laura Madalina
Published: March 2009

A comparative study of the in situ interactions between different maleic anhydride based
copolymers and calcium phosphates is presented in this paper. The ability of functional groups of
the organic polymers to form under high pressure and low temperatures chemical bonds with the
inorganic phase leading to improved properties of hybrid nanostructured material is discussed. The
open challenges of new hybrid nanocomposites in the field of biomedical materials are evaluated.
The challenge to use these nanostructured materials in medical field was evaluated by mapping the
interface reactions between hybrid active layers and cells.
Elastic Ceramic-Polymer Scaffold with Interconnected Pore Structure: Preparation and In Vitro Reactivity
Authors: Malin Minna , Korventausta Joni , Meretoja Ville , Seppälä Jukka
Published: March 2009

A series of ceramic-polymer scaffolds were studied for bone tissue engineering
applications. These applications require bone reactivity as well as suitable scaffold properties and
structure. Bioactive glass (BAG) and sol-gel derived silicas were chosen for ceramic components of
the scaffolds, and crosslinked poly(ε-caprolactone/D,L-lactide) copolymers with monomer ratios
90/10 and 70/30 were used as polymer matrices. Scaffolds were prepared by photo-curing
crosslinkable oligomers in the presence of the ceramic component and porosity producing salt.
Scaffolds with 60-80 vol-% continuous phase macroporosity were obtained by using calcium
chloride hexahydrate (CaCl2⋅6H2O), and were further tested in simulated body fluid (SBF). The
ceramics remained highly reactive during scaffold preparation resulting in in vitro calcium
phosphate formation.
Modified Poly-ε-Caprolactone (PCL) with Phosphorous Containing Compounds for Biomineralization
Authors: Puska Mervi , Korventausta Joni , Aho Allan , Seppälä Jukka
Published: March 2009

Biodegradable polymers (e.g. poly-ε-caprolactone, PCL) have been studied largely for tissue
engineering applications. The aim of this study was to evaluate the composite fabrication technique on
PCL modified with the phosphate salts (i.e. NaH2PO4, Na2HPO4, KH2PO4, or K2HPO4) as well as to
determine the compression strengths thereof. The chemical structure and morphology of composites were
analyzed using FTIR and SEM/EDX. The influence of a plain phosphate salt in different quantities on the
hydrophilic properties of PCL was evaluated by measuring the water contact angle. The results of this
study indicated that the addition of phosphate salts led to an improvement in compression strength of PCL
composites. According to the results of preliminary biomimetic mineralization, Na2HPO4 seems to
increase the bioactivity of PCL.
Formation of Titanium Oxide/Titanium/Plastic Composites
Authors: Watazu Akira , Teraoka Kay , Kido Hirofumi , Morinaga Kenzo , Okamatsu Kae , Nagashima Yoshiyuki , Matsuura Masaro , Saito Naobumi
Published: March 2009

Titanium oxide/ titanium/ plastic composite implants were formed by coating commercially pure titanium thin films on the surfaces of plastic cylinders by DC magnetron sputtering method. The composite is uniformly formed and the surface of the composite implant is smooth. The implants in rat tibias were not broken and the films on the surfaces of the samples did not decompose. The samples with bone were able to cut by diamond knife and observations between bone and titanium oxide on titanium by TEM succeeded. Therefore, the composite is useful for implants or observations the interactions between titanium oxide and bone in detail.
Determination Methods of Dialdehyde Celluloses from Bacterial Cellulose
Authors: Feng Yu Hong , Li Jia Cheng , Lin Qiang , Pang Su Juan , Zhang Meng Ying , Wang Xi Bin , Wu Zhou Xin , Sun Zhong Liang
Published: March 2009

This paper addresses the determination of aldehyde group (% of dialdehyde units) in dialdehyde cellulose (DACs) oxidized from bacterial cellulose (BC). With 4 determination methods, the oxidation degrees of DACs were studied: Automatic potential titration method through Schiff base reaction, Acid-base titration in Cannizzaro reaction, Metaperiodate consumption determination, and Measurement of amino nitrogen content in DAC derivatives. By comparing determination results of these methods, we found out the proper way suitable for this metaperiodate oxidation system of BC to measure the dialdehyde unit content of the DACs.
Surface Modification of Titanium by Hydrothermal Treatment
Authors: Obata Akiko , Kasuga Toshihiro
Published: March 2009

Titanium is well known as an implant material having excellent biocompatibility and
mechanical properties for use in bone substitute. In the present study, to enhance the
biocompatibility of titanium, its surface was modified by hydrothermal treatment using dilute
alkaline solution. After hydrothermal treatment, anatase predominantly formed on a titanium
surface. The anatase phase showed high crystallinity and c-axis orientation. The anatase layers
with leaf-like and pyramid-like forms were observed on titanium autoclaved at 120 °C and 240 °C,
respectively. The anatase formation and its morphology were significantly related to the
autoclaving temperature. To estimate the cellular compatibility of the autoclaved titanium, mouse
osteoblast-like cells (MC3T3-E1 cells) were cultured on the autoclaved titanium surface. After 7-
days culturing, the number of the cells harvested from the autoclaved titanium was higher than that
from untreated titanium. The surface modification of titanium by hydrothermal treatment involved
the proliferation of the cells on its surface.
Influence of Calcium Zirconium Phosphate Containing Coatings on Mineralization of Bone
Authors: Bernstein Anke , Nöbel Doreen , Mayr Hermann O. , Gildenhaar Renate , Berger Georg , Ploska Ute , Brandt Joerg
Published: March 2009

Bioactive ceramics such as hydroxypatite (HA) promote and enhance biological fixation.
There is still a discussion on the desired longevity of the coating. Stable coatings require an
optimum between resorption rate, flexural strength and adhesive strength of the coating.
Ceramic coatings containing fluorapatite (FA, Ca5(PO4)3F) and calcium zirconium phosphate
(CZP, CaZr4(PO4)6) promise lower resorption rates than conventional HA coatings in the biological
milieu. It is hoped that they can improve the long-term stability of implants by eliminating the
detrimental resorption of coating material. For the in vivo studies plasma sprayed coatings were
generated. The materials were implanted into the distal femur epiphysis of rabbits and investigated
after 2, 4, 6, 12, and 24 weeks postoperatively. Histological analysis was preformed on the areas
surrounding the implant. The amount of osseointegration was determined by using the
automatically image analysis. The bonding strengths were compared with HA coating and uncoated
titanium alloy. According to available data, there is inhibition of mineralization of bone at the
interface of calcium zirconium phosphate ceramics of the described composition.
Characterization and In Vivo Studies of Nanothickness Ca- and P-Based Coatings
Authors: Coelho Paulo Guilherme , Suzuki Marcelo , Fernandes C.A.O. , Cardaropoli G.
Published: March 2009

Objective: This series of laboratorial and in-vivo studies describe the characterization,
evolution, and in-vivo performance of various Ca- and P-based nanothicknesses and microstructures
ion beam assisted depositions (IBAD) onto Ti-6Al-4V implants. Materials and Methods:
Characterization- The 4 mm in diameter and 10 mm in length implant rods (Ti-6Al-4V) with IBAD
I, IBAD II, and control (alumina-blasted/acid-etched, AB/AE) surfaces were provided by an
implant manufacturer. The in-vitro characterization comprised the following techniques: (1)
SEM/EDS, (2) XPS/Depth Profiling (3) Thin-film XRD (4) AFM + ToF-SIMS for coating
thickness determination (5) AFM- Ra determination. In-vivo- Three animal experiments were
carried out for evaluation of the nanothickness bioceramic coatings. All experiments comprised a
proximal tibia model with 4-6 implants placed along the bones. Times in-vivo ranged from 2-5
weeks. Static (bioactivity, bone to implant contact) and dynamic (mineral apposition rates- MAR)
histomorphometric measurements were recorded. Biomechanical testing was performed by pullout
and torque to interfacial failure testing. Results: Combination of the characterization techniques
showed that all bioceramic coatings were Ca- and P-based bioceramics of amorphous
microstructure. AFM +ToF-SIMS showed that IBAD II coatings were thicker (300-500 nm)
compared to IBAD I coatings (30-50 nm). Surface roughness did not change significantly for the
IBAD implant groups compared to control. The in-vivo results showed higher degrees of
osseoactivity, torque to failure, and MAR for the coated implants at different times in-vivo. IBAD II
had higher biomechanical fixation at early implantation times compared to other groups.
Conclusions: The results obtained in the in-vitro part this study support that both IBAD I and IBAD
II coatings are Ca- and P- based amorphous bioceramics in the nanothickness range with theoretical
high dissolution rates. The increased osseoactivity observed for IBAD coated and the high MAR
values observed for IBAD coated compared to AB/AE implants support the effect of the bioceramic
coating presence in the overall bone healing. A thickness effect was reveled through biomechanical
testing where IBAD II (300-500nm thickness) presented higher performance.
Characterization of Titanium Oxide Thin Films Produced by Plasma Immersion Ion Implantation for Biomedical Implants
Authors: Uzumaki E.T. , Lambert C.S.
Published: March 2009

Plasma immersion ion implantation (PIII) is a very attractive method for the surface
treatment of titanium hard tissue replacements such as hip joints and enhancement of the
mechanical, chemical and biological properties of titanium. It has been considered as an alternative
to form protective and hard oxide films on titanium and titanium-based implants. In this study,
titanium oxide (TiO2) thin films were formed on titanium using PIII, which produces films with
adhesion superior to those prepared with conventional techniques. The films were analysed by
atomic force microscopy (AFM), X-ray diffraction (XRD) and pull test.
Improvement of Apatite-Forming Ability of Tantalum Metal by CaCl2 Treatment
Authors: Pattanayak Deepak K. , Matsushita Tomiharu , Takadama Hiroaki , Kokubo Tadashi , Nakamura Takashi
Published: March 2009

Tantalum metal was soaked in NaOH and CaCl2 solutions, and then subjected to heat
treatment at 500°C. EDX analysis showed that about 6.5 at. % of Na was incorporated into the
surface of the tantalum metal by the first NaOH treatment. These Na+ ions were replaced by Ca2+
ions by the subsequent CaCl2 treatment. According to TF-XRD patterns, an amorphous sodium
tantalate was seemed to be formed on the tantalum metal by the NaOH treatment and transformed into
amorphous calcium tantalate by the CaCl2 treatment. This phase was crystallized into Ca2Ta2O7 by heat
treatment. Critical detaching load of the surface of the CaCl2-treated tantalum metal was as low as
5mN, while as high as 42mN after the heat treatment. Apatite-forming ability of the NaOH-treated
tantalum metal in a simulated body fluid (SBF) was appreciably increased by the CaCl2 treatment
and maintained even after the heat treatment.
Sol-Gel Derived Methylsiloxane-Ca-Nb-Ta Coating on Titanium Surface by Double Layered Structure
Authors: Hoshikawa Yasuto , Yasuda Eiichi , Onoki Takamasa , Akao Masaru , Tanabe Yasuhiro
Published: March 2009

Titanium (Ti) and its alloy have sufficient mechanical properties to be utilized as artificial hip joints and article teeth. However, they have no bioactivity. In this work, we prepared bioactive coatings on Ti by sol-gel techniques. The coatings had a double layered structure. Underlying layer was methylsiloxane (MS) consisted of methyltriethoxysilane (MTES). Top layer was MS-Ca-Nb-Ta hybrid composed of MTES, calcium nitrate tetrahydrate, pentaethoxy-niobium and pentaethoxy-tantalum. The coating exhibited formation of bone-like apatite in SBF immersion test. Adhesive strength of the coating was found to be 1.8 MPa.
Relationship between Surface Residual Stress Fields and Hydrothermal Environment on Low Temperature Aging of 3Y-TZP
Authors: Ikeda Junji , Miyaji Fumiaki , Ueno Masaru , Pezzotti Giuseppe
Published: March 2009

Phase stability of 3 mol% yttria stabilized polycrystalline zirconia ceramics (3Y-TZP)
was evaluated by aging test in water vapor environment and Raman spectroscopic technique. In our
previous study, it has been confirmed that phase stability was improved by controlling sintering
temperature. In this study, we pointed our attention and evaluated the influence of surface
conditions related to machining and to heat treatment, thus monitoring the changes in phase
transformation fraction and residual stress on the material surface. From the results of aging test, an
increase in monoclinic fraction was observed for grinded surfaces as compared with polished
surfaces. Samples subjected to heat treatment after machining showed improved phase stability. A
Vickers indentation print was also introduced on a 3Y-TZP surface, and the relationship between
surface condition and low temperature aging was evaluated in the neighborhood of the print. We
found that the residual stress fields induced in phase-transformed areas were enhanced during low
temperature aging, and that phase stability was improved by heat treatment.
Preparation of Spherical Porous Granules Composed of Rod-Shaped Hydroxyapatite and Evaluation of their Protein Adsorption Properties
Authors: Takahashi Toshiharu , Kamitakahara Masanobu , Kawachi Giichiro , Ioku Koji
Published: March 2009

The present study examined the possibility of using spherical porous granules of hydroxyapatite
(HA, Ca10(PO4)6(OH)2) composed of rod-shaped particles as the drug delivery system. The granules
composed of rod-shaped HA were successfully prepared by an emulsion method and a hydrothermal
treatment. When the rod-shaped granules were soaked in phosphate buffer salines containing lysozyme
chloride or albumin, the granules of rod-shaped HA adsorbed more albumin than lysozyme. On the other
hand, the HA granules prepared by a normal sintering method adsorbed little lysozyme chloride or albumin.
The HA granules composed of rod-shaped particles are expected to be useful as carriers of negatively
charged substances.
Mechanical Properties of Newly Developed Root Canal Sealers Containing Titanium Oxide
Authors: Nakamura Ayami , Wanibe Harumasa , Iwama Akihiro , Kitamura Naritaka , Shibata Naoki , Nakata Kazuhiko , Tsuruta Shozo , Kawai Tatsushi , Nakamura Hiroshi
Published: March 2009

Titanium oxide (TiO2) has lately attracted considerable attention as a new material in
dentistry because of its catalytic activity and biocompatibility. In the present study, we developed a
novel root canal sealer consisting of TiO2 and evaluated its mechanical properties in vitro. The
newly developed root canal sealer containing TiO2 has satisfied the requirement of ISO formulation
6876. Our results suggest that the newly developed root canal sealer has excellent physical
characteristics, which may make it suitable for clinical use as a root canal sealer material.
The Effect of Etching Time to Durability of Dentin Adhesives
Authors: Kim J.R. , Jung M.R. , Park Sang Jin , Choi K.K.
Published: March 2009

The purpose of this study was to evaluate the effect of different etching times on microtensile bond strength(μTBS) to dentin both initial and after thermocycling with 3 different types of total-etching adhesives. Fifty four teeth were divided into 18 groups according to 3 etching times(5, 15, 25sec), 3 types of adhesives(Scotchbond Multipurpose(SM), Single Bond(SB), One-Step(OS)), and thermocycling(0, 2,000cycles). Following the bonding procedure, the specimens were bonded using Z250 composite. Half of them were not thermocycled (control group) and the others were subjected to 2,000 thermocycle (experimental group) and processed for microtensile bond strength testing. The microtensile bond strength(MPa) by different etching time(5, 15, 25s) was 37.7±9.1, 34.3±10.9 and 30.5±7.5 using Scotchbond Multipurpose(SM), 34.6±10.1, 33.8±7.6, 35.3±9.9 using single bond(SB) and 34.3±7.6, 31.3±8.5, 35.8±11.0 using one step(OS). After 2000 thermocycling the specimens, the microtensile bond strength(MPa) was decreased for all dentin bonding systems tested. But when specimens were bonded with OS, there is no significant difference between microtensile bond strength of the groups with the different etching times(5, 15, 25s) (28.2±7.8a , 29.1±8.6a and 28.2±9.4a). And the microtensile bond strength of the groups using SM, SB was decreased significantly when the etchant was applied for 25 sec(p<0.05). After all, the adhesive durability for dentin could be affected by type of solvents in adhesive and etching time. Especially, extended etching time may deteriorate dentin bond strength when ethanol-based adhesive was used
Towards Hierarchically Organized Scaffolds for Bone Substitutes from Wood Structures
Authors: Ruffini Andrea , Sprio Simone , Tampieri Anna
Published: March 2009

The development of innovative ceramic scaffolds for bone substitution with superior biomechanical features and smart anisotropic performances was performed through chemical and physical transformations of natural hierarchic structures, as trees, shrubs, palms, etc. These final structures will be highly organized from the molecular to nano, micro and macro-scales, with extremely functional architectures able to constantly adapt to ever changing mechanical and biofunctional needs. This study reports the preliminary results of the ceramisation process: starting from suitable vegetal raw materials pyrolysed to produce carbon templates characterized by complex pore structure, then infiltrated by vapour phase calcium to produce calcium carbide and finally transformed into porous ceramic of calcium carbonate by multi-step thermic and hydrothermal treatment in controlled environment.
Experimental Study on the Detection of Surface-Breaking Defects on Metal with the Scanning Laser Line Source Technique
Authors: Yan Gang , Ni Chen Yin , Shi Yi Fei , Shen Zhong Hua , Lu Jian , Ni Xiao Wu
Published: March 2009

The scanning laser line source (SLLS) technique is a novel laser-based inspection method for the ultrasonic detection of small surface-breaking defects. The SLLS approach is based on monitoring the change in laser generated ultrasound as a laser line source is scanning over a defect. It has provided enhanced signal-to-noise performance compared to the traditional pitch-catch or pulse-echo ultrasonic methods. In this paper, an experimental method is presented to detect surface acoustic waves (SAW) with polyvinylindene fluoride(PVDF) transducer. The ultrasonic signal is converted into electric signal by piezoelectricity of the PVDF, which is attached to a micro-knife edge clamped on a metal device. The SAW are excited by employing a pulsed Nd:YAG laser on aluminum plate with artificial surface-breaking defects. The laser line source is accurately shifted by the motorized translation stage, while the PVDF is located at a fixed position on the specimen. When the laser line source is scanning over the defect, the ultrasonic signals are monitored, meanwhile the characteristic changes in the amplitude and frequency content are observed. Consequently, the position of the defect can be determined by analyzing the obtained signals. The experimental system with high sensitivity provides a detection method of small surface-breaking defects on metal and gives convincing experimental evidence for the interaction mechanism between the SAW and the surface-breaking defects.
Correlation Study between a New Interferometric Asphere Metrology System and Fizeau Interferometer
Authors: Kuechel Michael F. , Sykora Daniel M.
Published: March 2009

Recent developments in next generation disc technology, cameras in mobile phones, zoom-lenses for small digital cameras and camcorders, digital SLRs, and television cameras have amplified the demand for affordable optical systems with outstanding image quality, a combination that can only be achieved using aspheric surfaces. The metrology of aspheric surfaces is a classical problem, but solutions so far have not fulfilled all demands for system cost, TACT (Total Average Cycle Time), minimized tooling, measurement uncertainty, spatial resolution, robustness in a production environment and many more. Zygo Corp. presents here a new method [1,2] for measurement of rotationally symmetrical aspheric surfaces using a new commercial system, which has the potential to fulfill these industry requirements. During measurement, the surface is scanned along its symmetry axis in a Fizeau cavity with a spherical reference surface. The coordinates x,y,z at the (moving) zone of normal incidence are derived from simultaneous phase-measurements at the apex and zone. Phase-shifting Fizeau interferometry and displacement interferometry are combined in the new commercial system to realize this new method. Aspheric departure from a best-fitsphere approaching 800 microns can be measured, and absolute measurement is possible with an absolutely calibrated transmission sphere. A custom parabolic artifact is measured with conventional null Fizeau interferometry and by the new commercial system. Data is reported for each technique along with a difference map achieved by fiducialized data subtract where 32.0 nm peak-to-valley (PV) and 3.6 nm R.M.S. are achieved.
Optical Design of Very Large Four-Mirror Systems
Authors: Zhu Li Rong , Shen Wei Min
Published: March 2009

Four-mirror systems with a very large aperture and a long focal length were investigated
and designed. Their design idea is given. Through the derivation of primary aberration formula, the
aberration properties were analyzed and discussed, and the method to determine its initial structure
is reported. As examples, two four-mirror systems with spherical and parabolic primary mirror,
100m focal length, and 10m entrance pupil were optimally designed. Their imaging quality
approaches diffraction limit within field of view of 0.4 and 0.5 degrees respectively.
A Study on Glass Molding Press and Pitch Error Analysis of a V-Grooved Quartz Fiber Array Block
Authors: Cho Un Chung
Published: March 2009

V-grooved quartz substrates are manufactured by glass molding press and the pitch errors
of the molded quartz fiber array blocks are statistically investigated. The V-grooved carbon molds
of 8 and 16 channels and 250 μm in pitch are machined and then quartz substrates are molded on
the V-grooved carbon molds by glass molding press. The pitch errors of X, Y and diagonal axis are
measured and then statically analyzed. It is demonstrated that the V-grooved quartz fiber array
blocks of 8 and 16 channels and 250 μm in pitch can be manufactured by glass molding technology
without significant pitch errors.
A Study of the Microstructure and Properties of Electroformed Ni-P Model Insert
Authors: Ke Shih Tsung , Lee Jeou Long , Yeh Yih Min , Lee Shuo Jen , Ger Ming Der
Published: March 2009

In this study, a Ni-P alloy electroforming nanostructure material with low surface
roughness and low internal stress was developed by using a pulse current. Square-wave cathodic
current modulation was employed to electrodeposit ultrafine-grained Ni-P films from an additivefree
Sulfamate nickel bath. The effect of various factors, such as peak current density, duty cycle
and pulse frequency on the roughness and internal stress were investigated. Pulse current
significantly influences the microstructure of Ni-P alloys. The internal stress and roughness of Ni-P
alloys increased as peak current density increased, but the internal stress of Ni-P alloys decreased as
duty cycle decreased.
An Investigation of Surface Grinding Characteristics for Titanium Alloy with CBN Wheel
Authors: Lin Shen Yung , Liu Y.C. , Huang C.W.
Published: March 2009

This study performs an experiment to investigate the effect of process variables such as
rotational cutting speeds of the wheel, feed rate of the work-table and grinding depth of cut on
surface roughness and the fluctuations of grinding forces for Ti-6Al-4V titanium alloy. STP-1623
ADC surface grinding machine, grinding wheel with CBN material sintering and Ti-6Al-4V
titanium alloy workpiece are used in the experiment. The roughness of the grinding surface was
measured by the roughness measuring instruments and the fluctuations of grinding forces were
measured through dynamometer after each surface layer ground from the workpiece in the
experiment. The grinding performance can be ascertained from the signal fluctuations phenomena
of the grinding forces both along normal and tangential directions, which may also be utilized as an
index for the quality of surface finish judgment. The results show that excellent surface quality
being always consistent with the stable grinding force fluctuations and can be obtained under the
conditions of slow feed rate of the work-table, high revolutions of the wheel and shallow depth of
cut.
Numerical Control Interpolation Algorithm of Aspheric Surface Based on the Genetic Algorithms and Neural Network
Authors: Zhang Fei Hu , Chen D.J. , Li L.J.
Published: March 2009

When the Neural Network model is used to interpolate the non-circular curves, there are shortcomings of converging slowly and getting into the local optimum easily. A novel numerical control interpolation algorithm based on the GA (Genetic Algorithms) and NN (Neural Network) was introduced for the ultra-precision machining of aspheric surfaces. The algorithm integrated the global searching of GA with the parallel processing of NN, enhanceed the convergence speed and found the global optimum. At the end, the quintic non-circular curve was taken as an example to do the emulation and experiment. The results prove that this algorithm can fit the non-circular curve accurately, improve the precision of numerical control interpolation and reduce the number of calculating and interpolation cycles.
Production of Micro-Optical Lenses Using Micro-Jet Drop-On-Demand
Authors: Nagao Mituo , Okabe Hiroshi , Oyoshi Kazuya , Sakano Susumu
Published: March 2009

MEM (Micro-Electro-Mechanical System) is the integration system of mechanical
elements, sensors, actuators, and electronics on a silicon substrate using the micro fabrication
technology, in general. A new MEMS formation technology is proposed in this paper. The
improved drop-on-demand ink jet was used and the MEMS was formed on the plastics and silicon
substrate. The plastics resins were injected from the drop-on-demand head on the substrate and the
dropped resins were cured using ultraviolet rays. Thus micro lenses were formed.
3D Micro-Scale Profile Measuring System
Authors: Young Hong Tsu , Lin Wei Yen
Published: March 2009

An optical non-contact measurement system for micro-scale 3D profiles is developed and
analyzed in this research. The core concept of the system is based on Shape-from-Focus method.
The methodology and the process of the measurement will be explained in this paper. Briefly,
corresponding digital images were taken at different heights with predefined step intervals. The
properties of images were enhanced by image processing techniques including discrete Gaussian
filtering, histogram equalization and high-boost filtering. Finally, the degree of the focused image
was quantified by using Sum-Modified-Laplacian algorithm. The height of each pixel was
determined with Gaussian Interpolation. 3D geometry model of the specimens can be reconstructed.
This system was verified that it can work on the specimen manufactured by laser beam. Analysis of
precision will be revealed and the comparison with other measurement methods will be discussed
later.
Analysis of Correcting Ability of Ion Beam Figuring
Authors: Zhou Lin , Dai Yi Fan , Xie Xu Hui , Jiao Chang Jun , Li Sheng Yi
Published: March 2009

In ion beam figuring process, typically, the smaller ion beam diameter has a good ability
to “correct” the optical surface error, i.e. the smaller ion beam diameter indicates the higher material
removal efficiency ε. The material removal efficiency is defined as the ratio of the volume of
desired material removal to that of the real material removal. However the smaller ion beam
diameter always results in more processing time, which usually decreases the process reliability. In
this paper, the relationship between the material removal efficiency and the ion beam diameter is
analyzed. The theoretical result shows that the material removal efficiency is a negative exponential
function of the ratio of ion beam diameter to the spatial error wavelength, (i.e. d/λ). And when d/λ=
0.5, the material removal efficiency is 87%, which is acceptable in ion beam figuring process.
When d/λ = 1, it rapidly decreases to 58%, which is unacceptable. According to theoretical analysis
and simulation results, we recommend that d/λ should be less than 0.5 in order to obtain acceptable
material removal efficiency in ion beam figuring process.
An Experimental Study on Flow Characteristics of PBK-40 for Glass Molding Press Simulation
Authors: Chang Sung Ho , Heo Young Moo , Shin G.H. , Lee Young Min , Kang Jeong Jin , Jung T.S.
Published: March 2009

Remarkable progress had been made in both technology and production of optical
elements including aspheric lens. Especially, requirements for machining glass materials have been
increasing in terms of limitation on using environment, flexibility of material selection and surface
accuracy. In the past, precision optical glass lenses were produced through multiple processes such
as grinding and polishing, but mass production of aspheric lenses requiring high accuracy and
having complex profile was rather difficult. Against such a background, the high-precision optical
GMP process was developed with an eye on mass production of precision optical glass pasts by
molding press. This GMP process can produce with precision and good repeatability special form
lenses such as for cameras, video cameras, aspheric lenses for laser pickup, f-θ lens for laser printer
and prism, and fine glass parts including diffraction grating and V-grooved base. Generally, GMP
process can be classified into batch and progressive type. In these types, because progressive type
has many merits in that productivity is higher and repair/retouch of mold is easier than batch type,
progressive GMP process is mainly used to produce aspheric glass lenses these days. In this paper,
as a fundamental study to develop the multi-cavity mold for higher productivity of progressive
GMP process used in fabrication of aspheric glass lens, compression tests for K-PBK40, which is
the material of aspheric glass lens, were conducted at high temperature. As a result, flow
characteristics of K-PBK40 were obtained for aspheric glass lens press simulation.
Analysis and Optical Design of 1:1 Projection Lithography System
Authors: Lin Qing Hua , Zhou Jin Yun , Li Wen Jing
Published: March 2009

For the 1:1 laser projection lithography system used to achieve large-area patterning with
higher resolutions as well as higher throughput, the key parameters such as the laser beam
geometry, the numerical aperture of projection lens, the laser source power and the pulse repetition
rate are theoretically analyzed. It is expounded the process of uniform exposure in hexagonal beam
shape, the advantages and limitations of 1:1 projection owing to numerical apertures deciding the
resolution, as well as the cause of choosing larger laser power and pulse repetition rate. Meanwhile,
the projection lens for a unit-magnification, refractive imaging system is tentatively simulationdesigned
using ZEMAX optical design software. The optimized three-dimensional layout is plotted.
For the designed results, the maximum optical path difference is smaller thanλ /4 within entire
visual field. The resolution for feature sizes 10μm can be achieved within depth of focus 400μm by
evaluating MTF. The maximum field curvature is within 10μm and the maximum distortion is small
than 0.000007%. This fulfills the demands in technical specifications.
Novel Error Separation Method for Straightness Measurement
Authors: Yin Zi Qiang , To Suet , Kong Ling Bao
Published: March 2009

novel time-domain error separation method which can reconstruct straightness profile
of workpiece exactly for on-machine measurement has successfully been developed. The proposed
method is based on difference measurement and can use two or three displacement probes. It
possesses following characteristics: (i) adapting to long or short workpiece, (ii) assuming no prior
knowledge, (iii) employing large shears, (iv) needing no accurate zero-adjustment of probes, and (v)
reconstructing various surfaces including smooth, non-smooth, periodic and non-periodic profiles
with no theoretical error. The shortest length which can be reconstructed exactly has been
calculated in time-domain method. The theoretical analysis justifies the effectiveness of this
method.
A Study on Tool Deflection Trend Using Real Captured Images in Micro Endmilling Process
Authors: Kim Gun Hee , Yoon Gil Sang , Heo Young Moo , Jang Sung Ho , Seo Tae Il , Cho Myeong Woo
Published: March 2009

Recently, ultra-precision micro patterns and shapes have been widely used in optical field.
Various methods which are based on semi-conductor fabrication methods are nowadays used in
fabrication of micro shapes and patterns, but micro endmilling technology has lately attracted
considerable attention because of various available materials, flexibility of process and
high-productivity. For the precision micro endmilling process, analysis of micro cutting error is
mandatory. In general, tool deflection is a major factor which causes cutting error and limits
realization of the high-precision cutting process. Specially, in micro endmilling process, micro tool
deflection generates very serious problems compared to macro tool deflection. In this paper, it is
performed to observe the real tool deflection shapes in micro endmilling process, so the trend of
micro tool deflection was analyzed using real captured images in this study. To get the real images of
micro tool deflection, micro slot cutting processes were executed under various cutting conditions
using micro endmill and the real images of tool deflection were obtained during cutting process by
high-speed camera. Finally, the extent of tool deflection was calculated by the deflection angle
according to cutting conditions and two trends (the point of first tool contact and the cutting stage) of
micro tool deflection were analyzed.
Ultraprecision Ductile-Regime Cutting of Optical Glass
Authors: Zhou Ming , Liang Ying Chun , Huang Shao Nan
Published: March 2009

Nano-indentation of glass SF11 was performed for understanding the material
deformation behavior in practical cutting process. Diamond cutting tests under different process
conditions, i.e. conventional turning and ultrasonic vibration assisted cutting, were also carried out.
Cleavage and microchipping appear to be the dominant tool wear mechanism based on the
analytical results of wear zone microstructure and machined surface topography. The change in the
tribology of the cutting process as well as the alteration of the deformation mechanism of the work
material in the cutting zone might be responsible for the reduction in tool wear in vibration cutting.
Current Situation and Trend of Ultra-Precision Abrasive Machining
Authors: Yuan Ju Long , Hu D.X. , Wang Zhi Wei , Wen Dong Hui
Published: March 2009

With increasing trend toward automatic manufacture and demands for improved quality, position of ultra-precision machining processes is considered as more and more important. As the main processes of ultra-precision machining, abrasive machining processes can be chiefly divided into free abrasive processes and fixed abrasive processes. Typical techniques such as chemicalmechanical polishing, ELID, Flat Honing and so on have been reviewed and compared with each other in preliminary aspects such as surface quality, finish accuracy and finish efficiency. The development trend of ultra-precision abrasive machining will have great efforts on realizing the integration with high accuracy, high efficiency and low cost.
Parameters Optimization of the Ultrasonic External Cylindrical Lapping Process for Nano ZTA Engineering Ceramics Using Response Surface Methodology
Authors: Jiao Feng , Zhao Bo , Liu Chuan Shao , Zhu Xun Sheng
Published: March 2009

Aimed at the precision machining characteristics of nano ZTA engineering ceramics
external cylindrical components, ultrasonic aided lapping experiments were carried out adopting inhouse
developed ultrasonic external cylindrical lapping device with solid abrasive material. To
obtain minimum surface roughness with constraint of the material removal rate, response surface
methodology (RSM) was adopted to analyze the experimental data, and suitable experiment design
was chosen to fit the response surface in this research. Second-order surface response models of
surface roughness and material removal rate were developed respectively, and the influence laws of
lapping parameters on surface roughness and material removal rate were clarified according to the
built models. Finally, parameters optimization of the ultrasonic external cylindrical lapping process
for nano ZTA engineering ceramics was realized using surface response methodology.