• Journal of Dental Rehabilitation and Applied Science
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• v.38 no.3
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• pp.171-177
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• 2022

Peri-implantitis is an inflammatory lesion of the periodontium surrounding an endosseous implant, with progressive loss of the supporting peri-implant bone. The main purposes of treatment for peri-implantitis due to biological factors include addressing the inflammation and restoring a healthy but reduced periodontium around the implant, similar to the treatment of periodontitis in natural teeth. The proposed treatment protocol includes surgical treatment, mainly resective surgery, after non-surgical treatment such as oral hygiene instructions, mechanical cleansing of the fixture, and general or topical antiseptic or antibiotic application according to the extent of inflammation. In this article, we present a 6-year follow-up case showing unusual marginal bone regeneration after resective surgery and decontamination of an implant surface for the treatment of peri-implantitis and discuss the possible reasons.

• Nuclear Engineering and Technology
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• v.55 no.6
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• pp.2256-2262
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• 2023

The electrochemical corrosion behaviors of SA106 Grade B (SA106B) carbon steel in H₂SO₄4-N₂H₄ and H₂SO₄-N₂H₄-CuSO₄ solutions at 95 ℃ have been investigated with the addition of commercial corrosion inhibitors (CI#30 and No. 570S), to determine the stability of SA106B in the hydrazine-based reductive metal ion decontamination (HyBRID) process. The potentiodynamic polarization experiment revealed that the corrosion inhibitors were capable of lowering the corrosion rate of SA106B in H₂SO₄-N₂H₄ solution. It was found that the corrosion inhibitors induced formation of fixed surface layer on the carbon steel upon the corrosion. This corrosion inhibition performance was reduced in the presence of CuSO₄ in the solution owing to the chemical reactions between organic compounds in the corrosion inhibitors and CuSO₄. CI#30 showed a better corrosion inhibition effect in the H₂SO₄-N₂H₄-CuSO₄ solution. Although the corrosion inhibitors can provide better stability to SA106B in the HyBRID solution, their application should be carefully considered because it may result in reduced decontamination performance and increased secondary waste generation.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2004.06a
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• pp.133-134
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• 2004

DUPIC (Direct Use of spent PWR fuel In CANDU) fuel cycle technology is being developed at Korea Atomic Energy Research Institute (KAERI). All the DUPIC fuel fabrication processes are remotely conducted in the completely shielded M6 hot-cell located in the Irradiated Material Examination Facility (IMEF) at KAERI. Undesirable products such as spent nuclear fuel powder debris and contaminated wastes are inevitably created during the DUPIC nuclear fuel fabrication processes.(omitted)

• The Journal of the Korean dental association
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• v.51 no.12
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• pp.650-657
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• 2013

The aim of this study was to achieve healing of Peri-implantitis defects and hard tissue augmentation using a bovine-derived bone mineral on the defect site. Two patients were treated with the surgical approach. With a full muco-periosteal flap elevation, the implant surfaces were exposed and granulation tissue removed around the implant and between the threads. Each surface of the contaminated implant was prepared with the air-abrasive device(PerioFlow$^{(R)}$) for decontamination. Bovine-derived bone mineral(Bio-Oss collagen$^{(R)}$) was then used to fill the defects and muco-periosteal flaps sutured to achieve transmucosal healing. Radiographs and clinical photographs were taken before and after 6 months of healing and an estimate of bone fill was assessed. Within the limits of the present case report, a surgical approach in treatment of peri-implantitis defects using a collagen form of bovine bone mineral was visited. Although limited, the two cases showed the stability and biocompatibility of a bovine-derived bone mineral and effectiveness of air-abrasive device(PerioFlow$^{(R)}$) as a decontamination method.

• The Journal of the Korean dental association
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• v.53 no.12
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• pp.906-909
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• 2015

Peri-implantitis is the inflammatory process, such as edema, bleeding, pus, of the mucosa surrounding dental implants. As the symptoms become severe, the surrounding bone is absorbed causing the implant surface to be exposed. Clinicians treat periimplantitis in various ways since a gold standard for the treatment of peri-implantitis has not been established. Various treatment methods include mechanical, chemical surface treatment and surgical excision, and recently decontamination of the implant surface using various types of lasers has been proposed. Thus, this study reviews the types of lasers and its effects that can be used for the treatment of peri-implantitis.

• Journal of Dental Rehabilitation and Applied Science
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• v.31 no.4
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• pp.340-348
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• 2015

Peri-implantitis is the most common reason for a late failure and can occur even after years of successful osseointegration. The role of microbial plaque accumulation in the development of peri-implantitis has been well documented. On the other hand, the ideal method of implant surface decontamination to re-establish the health of peri-implant tissue remains to be determined. Removal of bacterial deposits is essential in the treatment of peri-implant infections, and various therapeutic approaches have been described in the literature, including mechanical debridement, disinfection with chemotherapeutic agents, and laser therapy. Recently, there has been a plenitude of scientific data regarding the use of laser irradiation to achieve titanium surface decontamination. Thus, research is focusing on lasers' potential use in the treatment of peri-implantitis. The aim of this literature review is to analyze and evaluate the efficacy of laser therapy for the treatment of peri-implantitis.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.3 no.2
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• pp.149-157
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• 2005

PFC(Perfluorocarbon) decontamination process is one of best methods to remove hot particulate adhered at inside surface of hot cell and surface of equipment in hot cell. It was necessary to develop a particulate filtration equipment to reuse PFC solution used on PFC decontamination due to its high cost and to minimize the volume of second wastewater. Contamination characteristics of hot particulate were investigated and then a filtration process was presented to remove hot particulate in PFC solution generated through PFC decontamination process. The removal efficiency of PVDF(Poly vinylidene fluoride), PP(Polypropylene), Ceramic(Al$_{2}$O$_{3}$ filter showed more than 95$\%$. The removal efficiency of PVDF filter was a little lower than those of other kiters at same pressure(3psi). A ceramic filter showed a higher removal efficiency with other filters, while a little lower flux rate than other filters. Due to inorganic composition, a ceramic filter was highly stable against radio nuclides in comparison with PVDF and PP membrane, which generate H$_{2}$ gas in e-radioactivity atmosphere. Therefore, the adoption of ceramic filter is estimated to be suitable for the real nitration process.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.4 no.2
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• pp.161-170
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• 2006

PFC(Perfluorocarbon) decontamination process is one of best methods to remove hot particulate adhered on the inner surface of hot cell and surface of equipment in hot cell. It was necessary to develop a filtration equipment to reuse the PFC waste solution generated on PFC decontamination due to the high cost of PFC solution and for minimization of the volume of second waste solution. The filtration equipment was developed to remove hot particulate in PFC waste solution. It was made suitable size and weight in consideration of hot cell gate and crane. And it has wheels for easy movement. Flux of the filtration equipment decreased with particulate concentration increase. It consists of pre-filter($1.4{\mu}m$) and final-filter($0.2{\mu}m$) for protection of the flux decrease along filtration time. It treatment capacity of waste solution is 0.2 L/min.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.16 no.4
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• pp.421-429
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• 2018

Hydrazine based reductive dissolution applied on magnetite oxide was investigated. Dissolution of Fe(II) and Fe(III) from magnetite takes place either by protonation, surface complexation, or reduction. Solution containing hydrazine and sulfuric acid provides hydrogen to break bonds between Fe and oxygen by protonation and electrons for the reduction of insoluble Fe(III) to soluble Fe(II) in acidic solution of pH 3. In terms of dissolution rate, numerous transition metal ions were examined and Cu(II) ion was found to be the most effective to speed up the dissolution. During the cycle of Cu(I) ions to Cu(II) ions, the released electron promoted the reduction of Fe(III) and Cu(II) ions returned to Cu(I) ion due to the oxidation of hydrazine. In the experimental results, the addition of a very low amount of cupric ion (about 0.5 mM) to the solution increased the dissolution rate about 40% on average and up to 70% for certain specific conditions. It is confirmed that even though the coordination structure of copper ions with hydrazine is not clear, the $Cu(II)/H^+/N_2H_4$ system is acceptable regarding the dissolution performance as a decontamination reagent.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2009.06a
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• pp.84-85
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• 2009

New approaches for detecting, preventing and remedying environmental damage are important for protection of the environment. Procedures must be developed and implemented to reduce the amount of waste produced in chemical processes, to detect the presence and/or concentration of contaminants and decontaminate fouled environments. Contamination can be classified into three general types: airborne, surface and structural. The most dangerous type is airborne contamination, because of the opportunity for inhalation and ingestion. The second most dangerous type is surface contamination. Surface contamination can be transferred to workers by casual contact and if disturbed can easily be made airborne. The decontamination of the surface in the nuclear facilities has been widely studied with particular emphasis on small and large surfaces. The amount of wastes being produced during decommissioning of nuclear facilities is much higher than the total wastes cumulated during operation. And, the process of decommissioning has a strong possibility of personal's exposure and emission to environment of the radioactive contaminants, requiring through monitoring and estimation of radiation and radioactivity. So, it is important to monitor the radioactive contamination level of the nuclear facilities for the determination of the decontamination method, the establishment of the decommissioning planning, and the worker's safety. But it is very difficult to measure the surface contamination of the floor and wall in the highly contaminated facilities. In this study, the poly(styrene-ethyl acrylate) [poly(St-EA)] core-shell composite polymer for measurement of the radioactive contamination was synthesized by the method of emulsion polymerization. The morphology of the poly(St-EA) composite emulsion particle was core-shell structure, with polystyrene (PS)as the core and poly(ethyl acrylate) (PEA) as the shell. Core-shell polymers of styrene (St)/ethyl acrylate (EA) pair were prepared by sequential emulsion polymerization in the presence of sodium dodecyl sulfate (SOS) as an emulsifier using ammonium persulfate (APS) as an initiator. The polymer was made by impregnating organic scintillators, 2,5-diphenyloxazole (PPO) and 1,4-bis[5-phenyl-2-oxazol]benzene (POPOP). Related tests and analysis confirmed the success in synthesis of composite polymer. The products are characterized by IT-IR spectroscopy, TGA that were used, respectively, to show the structure, the thermal stability of the prepared polymer. Two-phase particles with a core-shell structure were obtained in experiments where the estimated glass transition temperature and the morphologies of emulsion particles. Radiation pollution level the detection about under using examined the beta rays. The morphology of the poly(St-EA) composite polymer synthesized by the method of emulsion polymerization was a core-shell structure, as shown in Fig. 1. Core-shell materials consist of a core structural domain covered by a shell domain. Clearly, the entire surface of PS core was covered by PEA. The inner region was a PS core and the outer region was a PEA shell. The particle size distribution showed similar in the range 350-360 nm.