• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2003.10a
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• pp.11-11
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• 2003

Electroplated hexavalent chromium coatings have been used in many technical applications since it was invented by G.J. Sargent in 1920. Because of the environmental problems and health risks associated with the use of hexavalent chromium, there has been an extensive search for alternative coatings with properties such as corrosion resistance and wear resistance, at a reasonable cost. However there is no single substitute that meets all the desirable performance characteristics of chromium. Advanced techniques, such as alloy plating, electroless plating, trivalent chromium plating, plasma and thermal spray coating, PVD and ion implantation, have been applied for replacing hexavalent chromium plating.

• Journal of Periodontal and Implant Science
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• v.35 no.2
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• pp.383-399
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• 2005

The successful implantation necessitate tissue regeneration m site of future implant placement, there being severe bone defect. Therapeutic approaches to tissue regeneration in the site have used bone grafts, root surface treatments, barrier membranes, and growth factors, the same way being applied to periodontal tissue regeneration. Great interest in periodontal tissue regeneration has lead to research in bone graft, guided-tissue regeneration, and the administration of growth factors as possible means of regenerating lost periodontal tissue. The blood component separated by centrifuging the blood is the platelet-rich plasma. There are growth factors, PDGF, $TGF{beta}1$, $TGF{beta}2$ and IGF in the platelet-rich plasma. The purpose of this study was to study the histopathological correlation between the use of platelet-rich plasma and the healing of bone defect around implant fixture site. Implant fixtures were inserted and graft materials were placed into the left femur of in the experimental group, while the control group received only implant fixtures. In the first experimental group, platelet-rich plasma and BBP xenograft were placed at the implant fixture site, and the second experimental group had platelet-rich plasma, BBP xenograft, and the e-PTFE membrane placed at the fixture site. The degree of bone regeneration adjacent to the implant fixture was observed and compared histopathologically at 2, 4, and 8 weeks after implant fixture insertion. The results of the experiment were as follows: 1. Bone remodeling in acid etched surface near the implant fixture of all experimental groups was found to be greater than new bone formation. 2. Bone remodeling in acid etched surface distant to the implant fixture of all experimental groups was decreased and new bone formation was not changed. 3. Significant new bone formation in machined surface near the implant fixture of bothl experimental groups was observed in 2 weeks. 4. New bone formation in machined surface distant to the implant fixture of both experimental groups was observed. Bone remodeling was significant in near the implant fixture and not in distant to the implant fixture. The results of the experiment suggested that the change of bone formation around implant. Remodeling in machined surface distant to the implant fixture of both experimental groups, and new bone formation and remodeling near the implant fixture were significant.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.35 no.6
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• pp.396-401
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• 2013

Chronic osteomyelitis is an infection and inflammation of the bone or bone marrow, causing ischemia in bone marrow due to lack of blood, nutrients, and oxygen supply to the bone marrow, eventually leading to necrosis of bone marrow. A current method for treatment of chronic osteomyelitis is administration of systemic antibiotics followed by removal of the infected bone and tissues. Because infected tissue of chronic osteomyelitis is surrounded by avascular necrotic bone, supply of blood and antibiotics to the infected area is diminished. For effective treatment, high plasma concentrations of antibiotics should be provided for a prolonged period. However, long term high serum level of antibiotics may result in undesirable adverse effects. For delivery of a sufficient concentration of antibiotic to the infected area while avoiding the adverse effect, implantation of a local antibiotic delivery system is suggested. One of the implantation systems that has been utilized is antibiotic impregnated polymethyl methacrylate.

• The Journal of Advanced Prosthodontics
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• v.6 no.3
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• pp.157-164
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• 2014

PURPOSE. This study focused on in vitro cell differentiation and surface characteristics in a magnesium coated titanium surface implanted on using a plasma ion source. MATERIALS AND METHODS. 40 commercially made pure titanium discs were prepared to produce Ti oxide machined surface (M) and Mg-incorporated Ti oxide machined surface (MM). Surface properties were analyzed using a scanning electron microscopy (SEM). On each surface, alkaline phosphatase (ALP) activity, alizarin red S staining for mineralization of MC3T3-E1 cells, and quantitative analysis of osteoblastic gene expression, were evaluated. Actin ring formation assay and gene expression analysis of TRAP and GAPDH performing RT-PCR were performed to characterize osteoclast differentiation on mouse bone marrow-derived macrophages (BMMs). RESULTS. MM showed similar surface morphology and surface roughness with M, but was slightly smoother after ion implantation at the micron scale. M was more hydrophobic than MM. No significant difference between surfaces on ALP activity at 7 and 14 days were observed. Real-time PCR analyses showed similar levels of mRNA expression of the osteoblast phenotype genes; osteopontin (OPN), osteocalcin (OCN), bone sialoprotein (BSP), and collagen 1 (Col 1) in cell grown on MM at 7, 14 and 21 days. Alizarin red S staining at 21 days showed no significant difference. BMMs differentiation increased in M and MM. Actin ring formation assay and gene expression analysis of TRAP showed osteoclast differentiation to be more active on MM. CONCLUSION. Both M and MM have a good effect on osteoblastic cell differentiation, but MM may speed the bone remodeling process by activating on osteoclast differentiation.

• Proceedings of the Korean Vacuum Society Conference
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• 2000.02a
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• pp.170-170
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• 2000

Synthetic polymers such as polyimide, polycarbonate, and poly(methyl methacrylate) are long chain molecules which consist of carbon, hydrogen, and heteroatom linked together chemically. Recently, polymer surface can be modified by using a high energy ion beam process. High energy ions are introduced into polymer structure with high velocity and provide a high degree of chemical bonding between molecular chains. In high energy beam process the modified polymers have the highly crosslinked three-dimensionally connected rigid network structure and they showed significant improvements in electrical conductivity, in hardness and in resistance to wear and chemicals. Polyimide films (Kapton, types HN) with thickness of 50~100${\mu}{\textrm}{m}$ were used for investigations. They were treated with two different surface modification techniques: Plasma Source Ion Implantation (PSII) and conventional Ion Implantation. Polyimide films were implanted with different ion species such as Ar+, N+, C+, He+, and O+ with dose from 1 x 1015 to 1 x 1017 ions/cm2. Ion energy was varied from 10keV to 60keV for PSII experiment. Polyimide samples were also implanted with 1 MeV hydrogen, oxygen, nitrogen ions with a dose of 1x1015ions/cm2. This work provides the possibility for inducing conductivity in polyimide films by ion beam bombardment in the keloelectronvolt to megaelectronvolt energy range. The electrical properties of implanted polyimide were determined by four-point probe measurement. Depending on ion energy, doses, and ion type, the surface resistivity of the film is reduced by several orders of magnitude. Ion bombarded layers were characterized by Time-of-Flight Secondary Ion Mass Spectrometry (TOF-SIMS), XPS, and SEM.

• Journal of the Korean institute of surface engineering
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• v.34 no.5
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• pp.414-420
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• 2001

A 30-kV plasma immersion ion implantation setup (P $I^3$) has been equipped with a self-developed 6'-magnetron to perform hard coatings with enhanced adhesion by P $I^3$D(P $I^3$ assisted deposition) process. Using ICP source with immersed Ti antenna and reactive magnetron sputtering of Ti target in $N_2$/Ar ambient gas mixture, the TiN films were prepared on Si substrates at different pulse bias and ion-to-atom arrival ratio ( $J_{i}$ $J_{Me}$ ). Prior to TiN film formation the nitrogen implantation was performed followed by deposition of Ti buffer layer under A $r^{+}$ irradiation. Films grown at $J_{i}$ $J_{Me}$ =0.003 and $V_{pulse}$=-20kV showed columnar grain morphology and (200) preferred orientation while those prepared at $J_{i}$ $J_{Me}$ =0.08 and $V_{pulse}$=-5 kV had dense and eqiaxed structure with (111) and (220) main peaks. X-ray diffraction patterns revealed some amount of $Ti_{x}$ $N_{y}$ in the films. The maximum microhardness of $H_{v}$ =35 GN/ $M^2$ was at the pulse bias of -5 kV. The P $I^3$D technique was applied to enhance wear properties of commercial tools of HSS (SKH51) and WC-Co alloy (P30). The specimens were 25-kV PII nitrogen implanted to the dose 4.10$^{17}$ c $m^{-2}$ and then coated with 4-$\mu\textrm{m}$ TiN film on $Ti_{x}$ $N_{y}$ buffer layer. Wear resistance was compared by measuring weight loss under sliding test (6-mm $Al_2$ $O_3$ counter ball, 500-gf applied load). After 30000 cycles at 500 rpm the untreated P30 specimen lost 3.10$^{-4}$ g, and HSS specimens lost 9.10$^{-4}$ g after 40000 cycles while quite zero losses were demonstrated by TiN coated specimens.s.

• Journal of Embryo Transfer
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• v.2 no.1
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• pp.36-46
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• 1987

The present work was designed to understand the mechanism of superovuiation and the cause of early embryo loss and Implantation failure in the superovulating immature female rats which were elaborated by a pituitary gland transplantation. A pituitary gland obtained from the orchidectomized rats was transplanted under the right kidney capsule of 28 day old female rats (PGT group) on the starting day of experiment which was designated as Day 2. The grafted pituitary glands were removed at 6h (RPGT 6h group), 12h (RPGT 12hgroup) and 24h (RPGT 24h group) after the transplantation. Control rats were treated with 41U PMSG on Day 2 (PMSG group). The estrous cycle and the levels of plasma progesterone and estradiol-17$\beta$ were observed on Day 0, Day 5, respectively. The implantation sites, the weights of ovary and uterus, and the number of corpora lutea were examined in all group on Day 8. The resuft obtained were summarized as follows: 1. The percentages of the number of the rats in proestrus and estrus were 93.0%, 82.6%, 0%, 90.7% and 89.5% in PMSG, PGT, RPGT6h, RPGT12h and RPGT24h group, respectively. The synchronization of estrus cycle was dchieved in all groups. 2. The mating rates of each group were 80.2, 75.0, 0, 56.4, 57.8% in PMSG, PGT, RPGT6h, RPGT12h, RPGT24h group, respectively. 3. The numbers of copora lutea on Day 8 were 47.1 i 4.9, 18.1 $\pm$0.5, 14.1 i 0.3 and 8.9 $\pm$ 0.3 in PGT, RPGT24h, RPGTl2h and PMSG group, respectively. There were signIficantly difference between all groups (P<0.05). 4. The numbers of implantation sites (18.1 +- 4.0) in PGT group on Day 8 were higher than those of PMSG (8.5 $\pm$ 2.5), RPGT 12h (9.8 i 0.2) and RPGT 24h group (10.8 i 0.2) (P<0.05). 5. The ovarlan weights in PGT (95.2 $\pm$ 14.3mgIlOOg BW), RPGT 12h (51.7 $\pm$ 0.6mgIlOOg BW), and RPGT24h (57.9 $\pm$ 0.9mg/l00g 8W) groups were significantly higher than those of PMSG group (30.4 $\pm$7.4mg/l00g BW) (P<0.05). 6. The uterine weights in PMSG (672.4 $\pm$ 4.7mg/l00g 8W), and PGT (660.7 $\pm$7.8mg/l00g BW) groupswere greater than those of RPGT 12h (403.0 $\pm$ 1.lmg/lOOg BW) and RPGT 24h (490.1 $\pm$ 0.9mg/l00g BW) group (P<0.05). 7. The plasma progesterone levels in PGT groups (15 lng/ml) on Day 5 were higher than those of PMSG (83ng/ml), RPGT 12h (S7ng/ml), RPGT24h (8lng/ml) group (P<0.05). 8. The plasma estradiol-17$\beta$ levels in PMSG group (lBSpg/ml) on Day S were higher than those of RPGT 24h (l3pg/ml) group (P<0.05). But estradiol-17$\beta$ levels in PGT and RPGT 12h group were too low to discuss.

• Journal of the Korean Vacuum Society
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• v.18 no.3
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• pp.236-243
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• 2009

Proton Engineering Frontier Project (PEFP) has supplied the metal ions to users by using an installed metal ion implanter of 120 keV. At present a feasibility study is being performed for a cobalt ion implantation. For a cobalt ion extraction we studied to sustain the high temperature($648^{\circ}C$) for metal ions vaporization from a cobalt chloride powder by using an alumina crucible in the ion source. The temperature condition of the crucible was satisfied with the plasma generation at the arc current of 120V and EHC power of 250W. The extracted beam current of $Co^+$ ions was dependent on the arc current in the plasma. The maximum beam current was $100{\mu}A$ at 0.18A of the arc current. The 3 peak currents of the extracted ions such as $Co^+$, $CoCl^+$ and $Cl^+$ were obtained by adjusting a mass analyzing magnet and the $Co^+$ ion beam peak current fraction as around 70% in the sum of the peak currents. The fluence of the implanted cobalt ions at the $10{\mu}A$ of the beam current and 90 minutes of the implantation time into an aluminum sample as measured around $1.74{\times}10^{17}#/cm^2$ by a quantitative analysis method of RBS (Rutherford Backscattering Spectrometry).

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.36 no.2
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• pp.71-77
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• 2010

Introduction: The purpose of this study is to evaluate the effect of platelet rich plasma in bone formation and osseointegration of implant installed in the bone marrow space. Materials and Methods: Five beagle dogs were used as experimental animals. Two implants were installed on each tibia in the dogs. Implants of the control group were installed with no additional graft. Those of the experimental group 1 were installed with autogenous bone graft from the ilium autogenous bone. Platelet rich plasma (PRP) alone was used in experimental group 2 and the mixture of PRP and autogenous bone was used in experimental group 3. The animals were sacrificed at 8 weeks after implantation. The parts of tibia containing implant were harvested and radiographs were taken for radiographic examination. The specimens were prepared for histological examination and histomorphometric analysis of implant-bone contact ratios. Results: 1. All implants showed sufficient osseointegration in the cortical bone radiographically and histologically, but osseointergration in the marrow space was not satisfactory. 2. Histomorphometrically, the implant-bone contact ratios in the bone marrow was sequentially high in the experimental group 3 (autogenous bone + PRP group), group 1 (autogenous bone group), group 2 (PRP group), and control group (non-additive). 3. It was verified that there was statistical significance between two experimental groups (group 1 and 3) and the other groups (group 2 and control group). (P<0.005) 4. However, there was no statistical significance between group 3 and group 1, also group 2 and control group respectively. Conclusion: These results suggest that platelet rich plasma is effective to osseointegration in the implant installation but there is no statistical significance.

• Korean Journal of Materials Research
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• v.22 no.2
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• pp.66-70
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• 2012

Ti-Ni alloys are widely used in numerous biomedical applications (e.g., orthodontics, cardiovascular science, orthopaedics) due to their distinctive thermomechanical and mechanical properties, such as the shape memory effect, superelasticity and low elastic modulus. In order to increase the biocompatibility of Ti-Ni alloys, many surface modification techniques, such as the sol-gel technique, plasma immersion ion implantation (PIII), laser surface melting, plasma spraying, and chemical vapor deposition, have been employed. In this study, a Ti-49.5Ni (at%) alloy was electrochemically etched in 1M $H_2SO_4$+ X (1.5, 2.0, 2.5) wt% HF electrolytes to modify the surface morphology. The morphology, element distribution, crystal structure, roughness and energy of the surface were investigated by scanning electron microscopy (SEM), energy-dispersive Xray spectrometry (EDS), X-ray diffractometry (XRD), atomic force microscopy (AFM) and contact angle analysis. Micro-sized pores were formed on the Ti-49.5Ni (at%) alloy surface by electrochemical etching with 1M $H_2SO_4$+ X (1.5, 2.0, 2.5) wt% HF. The volume fractions of the pores were increased by increasing the concentration of the HF electrolytes. Depending on the HF concentration, different pore sizes, heights, surface roughness levels, and surface energy levels were obtained. To investigate the osteoblast adhesion of the electrochemically etched Ti-49.5Ni (at%) alloy, a MTT test was performed. The degree of osteoblast adhesion was increased at a high concentration of HF-treated surface structures.