• The Journal of Korean Academy of Prosthodontics
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• v.60 no.3
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• pp.254-262
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• 2022

When treating partial edentulous patients, it is important to use an appropriate restorative materials. Inappropriate restorative materials can adversely affect the outcome of prosthetic restorations. Zirconia and dental metal, which are currently and widely used materials, have a higher elastic modulus than cortical bone, so when an external force is generated, a harmful force can be applied to the implant and the bone around the implant. Polyetherketoneketone (PEKK), a recently introduced material, has a elastic modulus similar to that of cortical bone, and has many advantages in terms of physical properties and biocompatibility. This case report describes that implant-supported fixed prosthetic treatment using PEKK was performed, and functional and esthetic satisfactory results were obtained.

• The Journal of Korean Academy of Prosthodontics
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• v.60 no.4
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• pp.431-441
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• 2022

The digital facebow device records the trajectory of the mandibular movement where it is then reflected on the computer-aided design software, leading to an improvement on treatment outcomes of prosthetic restorations. In this clinical case, using a digital technology, an implant placement and prosthetic restoration were done in a patient who has lost maxillary and mandibular molars. Following an intraoral scan, a surgical stent for implant surgery was fabricated based on digital diagnostic wax-up, and implants were installed. After six months of sufficient osseointegration, customized abutments and the first temporary prostheses were delivered. Then two months later, at an abutment level, an intraoral scan and digital facebow transfer device were used to mount the intraoral scan data on a virtual articulator, and record the mandibular movements. Once the second temporary prostheses were fabricated and delivered on a basis of the mandibular movement, the definitive zirconia prostheses were designed and delivered based on a stabilized occlusion that was duplicated via double scan technique.

• Journal of Dental Rehabilitation and Applied Science
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• v.34 no.1
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• pp.46-55
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• 2018

Oral rehabilitation of a patient having severe periodontitis with alveolar bone resorption and periodontal inflammation presents a challenge to clinicians. However, if appropriate implant placement according to the bone shape is selected, unnecessary bone grafting or soft tissue surgery can be minimized. In recent years, using cone beam CT and software, it has become possible to operate the planned position with the surgical guide made with 3D printing technology. This case was a 70 years old female patient who required total extraction of teeth due to severe periodontitis and performed a full-mouth rehabilitation with an implant - supported fixed prosthesis. During the surgery, the implant was placed in a flapless manner through a surgical guide. Immediate loading of the temporary prosthesis made by CAD/CAM method before surgery was done. Since then, we have produced customized abutments and zirconia prostheses, and have reported satisfactory aesthetic and functional recovery.

• Proceedings of the Korean Society of Disaster Information Conference
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• 2022.10a
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• pp.139-140
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• 2022

본 연구는 재난발생 시 현장 상황 판단 및 대응 능력이 현저히 떨어지는 안전취약계층 중 장애인과 노인이 재난정보를 받고 안전하게 대피·대응할 수 있도록 지원하는 시스템의 시범적용에 대한 것이다. 재난정보 전달 및 대피지원 시스템은 재난에 취약한 장애인과 노인이 재난상황에서 각각의 취약 특성을 고려하여 재난 위기상황에 대응하도록 설계 하였으며, 실내 위치측정에 관한 공간정보 표준 및 데이터 구축과 개발한 시스템을 설치하고 구현할 수 있는 실내 공간을 선정하여 시범적으로 적용하였다. 재난정보 및 대피지원 시스템의 시범적용을 위해 선정된 시설의 실내 공간정보 구축 및 현행화를 통해 실내 대피경로를 구축하고, 실제 시범적용을 통해 보완하는 과정을 수행하였다. 장애인·노인 대상 재난정보 전달 및 대피지원 서비스 구축을 위해 실내에서 재난발생 시 재난정보 데이터를 실시간으로 수집하고 스마트폰과 연계할 수 있는 연계 모듈을 개발하였다. 또한 재난정보를 스마트폰에 알릴 수 있는 알람 푸시 모듈, 재난정보 및 대피 안내 모듈과 시각 장애인의 실내 공간 인지를 위한 음성안내 모듈을 개발하였다. 본 연구의 목적은 IoT 기반의 통합관제 기술을 활용하는 서비스 제공을 통해서 정보전달의 사각지대를 해소하고 장애인·노인의 효율적 재난 대응을 위해 맞춤형 재난정보 전달 및 대피지원 서비스를 구축하고 시범적용의 과정을 통해 문제점을 보완하여 최종적으로 재난으로부터 안전취약계층의 안전성을 향상시키는데 목적이 있다.

• Journal of the Korean association of regional geographers
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• v.21 no.4
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• pp.631-638
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• 2015

The aim of this article is to analyze problems of the government-led region-based business-university-research institute collaborations(BURIC) in Korea and to present main issues for solving and improving the current 'cul-de-sac' of these collaborations. The main problem of such collaborations is the wider divergence of opinions by actors who implement projects of the BURIC funded by the central and local government. Due to this problem, each region, mainly the non-Seoul metropolitan region, in Korea has problems of the system and people for BURIC. Within this context, main issues of the government-led and region-based BURIC is focused upon BURIC for the start-up of self-employment and the expansion of companies' lifespan. Since 2000, experts and policy-makers have emphasized business- (or company-) centered BURIC rather than University-focused one. This point of view should be improved or corrected. That is to say, policies of BURIC are in need of focusing upon the start-up for self-employment and the expansion of companies' lifespan.

• The Journal of Korean Academy of Prosthodontics
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• v.56 no.3
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• pp.206-211
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• 2018

Purpose: Recently, a method of forming a slot in the prosthesis lingual has been introduced to solve the occlusal and aesthetic disadvantages of screw-retained prosthesis in the manufacture of implant-fixed prosthesis and to ensure retrievability in cement retained prostheses. The purpose of this study is to investigate the effect of the internal gap on the removal of the prosthesis in the preparation of cement-retained implant prostheses with lingual slots. Materials and methods: Titanium abutment and internal gap of the zirconia prosthesis to be attached to the upper part were set to 30, 35, and $50{\mu}m$, respectively. Three for each type total 15 were produced for each type. The zirconia prosthesis formed a retrievable cement-type slot with a space of 1 mm at the location where the titanium abutment meets the shelf area. Autocatalytic resin cement was used for bonding of abutment and zirconia prosthesis, and the maximum removal stress value was measured in units of Ncm by using the customized equipment of the cemented specimen. The Kruskal-Wallis test was used to compare the three groups by statistical analysis (${\alpha}=.05$), modified by post hoc test the Mann-Whitney U-test and the Bonferroni correction method were used to compare the two methods (${\alpha}=.017$). Results: There was no statistically significant difference in removal stress between the $30{\mu}m$ group and the $35{\mu}m$ group in the internal gap (P = .032), and there was a significant difference between the $30{\mu}m$ group and the $50{\mu}m$ group, between the $35{\mu}m$ group and the $50{\mu}m$ group (P < .017). Conclusion: Thus, the internal gap of computer-aided design affected the retention between the zirconia prosthesis and the titanium abutment.

• The Journal of Korean Academy of Prosthodontics
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• v.56 no.3
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• pp.188-198
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• 2018

Purpose: Recently, according to the development of digital technology, computer aided design/computer aided manufacture (CAD/CAM) system is widely used for fabrication of various dental prostheses in the field of dentistry. This study aims to survey the present state and awareness of CAD/CAM system on domestic dental field, and to supply the advice for the application of the new system. Materials and methods: In this questionnaire survey was conducted for a total of 298 dentists, dental hygienist and dental technicians of the whole country including the dental hospital of Seoul National University for two months from November to December, 2016 through mail. Results: The most important purpose to consider when purchasing a dental CAD/CAM milling machine were the performance of the milling machine (64.43%) and the use of milling machine was the highest with 49.33% of manufacturing for dental prosthesis and customized implant abutment. In addition, more than 60% of respondents answered positively about the purchase of new milling machine if the CAD/CAM milling machine was improved to satisfactory performance. Conclusion: This survey results show that the improved CAD/CAM milling machine would be play an important role in the dental industry in preparation for digitization and the 4th industrial revolution.

• Journal of Korea Port Economic Association
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• v.27 no.1
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• pp.13-30
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• 2011

It's vital to establish the competitive comparative advantage as the competitions among global logistics companies have become fierce. The global companies, hence, must innovate their Port Hinterland to hub and spoke in a view of SCM. The Port Hinterland significantly affects its local economy and value added. The task of the Port Hinterland nowadays is to improve its efficiencies by utilizing logistics operations and services. The Korean government has planned to reduce the scale of the Port. The CCR and BCC matrices show that there are nine efficient companies: two companies in Gwangyang Hinterland and five companies in Busan Hinterland, though Masan FTZ was only ranked on the 24th, on the rank of world FTZ. This paper aims at finding the cargo volume necessary for achieving the maximum efficiency. This research proposes an appropriate strategy to keep a certain amount of cargo volume stable and presents the Port Hinterland differentiation strategies of Gwangyang and Busan.

• The Journal of Korean Academy of Prosthodontics
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• v.59 no.1
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• pp.97-106
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• 2021

Dental implants should be placed at ideal sites for implant-supported restorations. For a patient with insufficient residual ridge, mouth preparation including surgical intervention can be indicated to establish a soft and hard tissue environment favorable for a definitive prosthesis. Prosthodontic design based on computer-guided surgery and computer-aided design-computer-aided manufacturing (CAD-CAM) provides a visual blueprint allowing a clinician to assess the necessity of such a surgical intervention beforehand. In this case, a definitive restoration was planned and made via a CAD-CAM system according to the patient's oral status before treatment, simulated surgical interventions and serial provisional restorations. Based on the planning, a guided template was made and the implants were installed with bone augmentation using the template. Customized abutments, the first and the second provisional restorations were designed and fabricated by CAD-CAM. The definitive restorations were digitally made following the shape of the second provisional prostheses, which were confirmed in the patient's mouth. The patient was satisfied with the masticatory, phonetic and aesthetic functions of these definitive prostheses.

• The Journal of Korean Academy of Prosthodontics
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• v.60 no.2
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• pp.168-174
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• 2022

In case of gingival recession or bone defect in maxillary anterior implant treatment, it is not easy to obtain satisfactory clinical results. In this case, loss of the labial alveolar plate was diagnosed in the maxillary right central incisor, so after tooth extraction, soft tissue was secured and implant placement with bone graft was planned. In addition, digital guide surgery was performed for the ideal implant position, and GBR (Guided Bone Regeneration) was accompanied with the xenogeneic bone and the autologous bone collected from the mandibular ramus since alveolar bone defects were extensive. After a sufficient period of osseointegration of the implant, a temporary prosthesis was fabricated through secondary stage surgery and impression taking, and through periodic external adjustment, the shape of soft tissue was improved. In the final prosthesis fabrication, a color tone of natural teeth was induced by an gold anodized customized abutment, and an aesthetic and functional zirconia prosthesis with reproducing the shape of the temporary prosthesis through intraoral scan was delivered.