• Journal of Periodontal and Implant Science
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• v.33 no.3
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• pp.499-518
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• 2003

The surface characteristics of titanium have been shown to have an important role in contact ossseointegration around the implant. Anodizing at high voltage produces microporous structure and increases thickness of surface titanium dioxide layer. The aim of present study was to analyse the response of rat calvarial osteoblast cell to commercially pure titanium and Ti-6A1-4V anodized in 0.06 mol/l ${\beta}$-glycerophosphate and 0.03 mol/l sodium acetate. In this study, rat calvarial osteoblasts were used to assay for cell viability and cell proliferation on the implant surface at 1,2,4,7 days. 1. Surface roughness was 1.256${\mu}m$ at 200V, and 1.745${\mu}m$ at 300V. 2. The thickness of titanium oxide layer was increased 1 ${\mu}m$ with the increase of 50V. 3. The proliferation rate of osteoblastic cells was increased with the increase of the surface roughness and the thickness of titanium oxide layer. 4. There was no difference in cell viability and cell proliferation between commercially pure titanium and Ti-6A1-4V anodized at the same condition. In conclusion, the titanium surface modified by anodizing was biocompatible, produced enhanced osteoblastic response. The reasons of enhanced osteoblast response might be due to reduced metal ion release by thickened and stabilized titanium dioxide layer and microporous rough structures.

• Journal of Technologic Dentistry
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• v.42 no.2
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• pp.149-162
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• 2020

Purpose: The purpose of this study was to conduct a cost accounting of implant prosthesis according to the fabrication activities. Methods: In this study, the cost price of implant prosthesis fabrication activities was calculated by the bottom-up costing approach for material and labor cost and the top-down costing approach for expenses and other. Results: The total cost price was estimated to 220,000 ~ 310,000 won per one implant prosthesis. By product, the screw type was estimated to 220,000 ~ 230,000 won, and when the stent and tray were included, it was 260,000 ~ 270,000 won, which increased about 40,000 won. And, the cement type with more material and labor time was estimated to 250,000 ~ 260,000 won, and when the stent and tray were included, it was about 300,000 won. Conclusion: In terms of the fabrication cost ratio by items, it was shown that material cost and labor cost accounted for about 40% and 30% of the total cost structure for resin case, respectively, which was the opposite for porcelain. It was shown that expenses and general administrative expenses accounted for about 15%, and profits were about 11% ~ 14% in both cases.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.3
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• pp.188-193
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• 2011

The osseointegration of dental implant is influenced by many factors such as surface geometry, loading and the amount of bone. Thus, stability of the dental implant should be checked periodically. In order to test the stability of dental implant by using resonance frequency analysis, we designed a structure of transducers and fabricated a piezoelectric devices. Using finite element analysis, the thickness and length of piezoelectric device and transducers were tailorized and the optimized frequency of 10 kHz was obtained. The resonance frequency from simulation analysis and evaluation was estimated to be similar as 10 kHz. The osseointegration was further enhanced with increasing frequency from the evaluation result of the finite element analysis.

• The Journal of Korean Academy of Prosthodontics
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• v.51 no.4
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• pp.252-260
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• 2013

Purpose: After the introduction of concept of osteointegration, dental implantology have been successful procedure in the dental field. Recently, it has shown successful results when used to restore single tooth missing. Considering the difference in bone quality of the mandible and maxilla, and the increased occlusal force in the posterior region, the success rates in each region may be different. In this study, success rates of single implants placed in the mandibular first and second molar areas were analyzed. Materials and methods: The subjects were patients (284 patients, 308 implants) who had been operated with single implant installation from 2002 to 2009 in seven dental clinics in Daegu city. One hundred sixty eight implants were placed in the mandibular 1st molar and 140 implants were placed in the mandibular 2nd molar. They were analyzed according to implant site, age, sex, length and diameter. Results: The survival rates of single implant of this study were 97.6% in the mandibular 1st molar and 92.9% in the mandibular 2nd molar. In the mandibular 1st molar, 4 implants were failed. In the mandibular, 2nd molar, 10 implants were failed. Conclusion: The restoration of the mandibular 1st molar using single implant was found to be clinically acceptable treatment and showed higher survival rate than mandibular 2nd molar single implant. Single implant in mandibular 2nd molar needs careful consideration of poor bone quality, risk of overloading and anatomical structure of the mandible.

• The Korean Society of Law and Medicine
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• v.17 no.1
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• pp.281-297
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• 2016

In order to make a treatment plan and outcome prediction, it is important to evaluate accurately and objectively osseous tissues of the implant area. The evaluation of osseous tissues is the most objective method for the decision of production time of upper structure of alveolar bone. However, the evaluation of osseous tissues contains contradiction because it is made by subjective opinions of dental surgeons. Many dentists also point out the problem of subjective evaluation of osseous tissues. Therefore, it is necessary to create accurate and objective standards. Previously, the evaluation of bone density depends on dentist's subjective sensation during drilling procedure of implant. However, the HU(Hounsfield unit) figure of CT(computed tomography) scan allows of objective and precise categorization of bone density now. Misch and Kircos divided the bone density levels from D1 to D5 with subjective separation of bone density. Their method also depended on not objective and quantification data but subjective separation by sensation. Thus, we need the evaluation of implant area through comparative analysis of more objective and quantification data. Implant treatment comprises the highest frequency of medical disputes of dental clinic. If we bring objective checkup and reasonable treatment method in the implant treatment, we can deduce more reasonable results, and the failure late of implant treatment also can decrease. The ultimate objective of this study is the minimization of dental disputes between dental patients and dentists by creating new legal standards on the basis of objective and quantification data.

• Journal of Satellite, Information and Communications
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• v.10 no.4
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• pp.6-11
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• 2015

The ESD(electrostatic discharge) protection performance of PPS(PMOS pass structure) embedded N-type silicon controlled rectifier(NSCR_PPS) device with different GPNS(Gate to Primary $N^+$ Diffusion Space) structure was discussed for high voltage I/O applications. A conventional NSCR_PPS standard device with FPW(Full P-Well) structure and non-CPS(Counter Pocket Source) implant shows typical SCR-like characteristics with low on-resistance(Ron), low snapback holding voltage(Vh) and low thermal breakdown voltage(Vtb), which may cause latch-up problem during normal operation. However, our proposed NSCR_PPS devices with modified PPW(Partial P-Well) structure and optimal CPS implant demonstrate the improved ESD protection performance as a function of GPNS variation. GPNS was a important parameter, which is satisfied design window of ESD protection device.

• Proceedings of the IEEK Conference
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• 1998.10a
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• pp.557-560
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• 1998

We previously developed and presented the 3D ion implantation simulation code, TRICSI. In this paper, we performed the multiple implants into (100) silicon substrate with our recently enhanced version. Our results for the multiple implants were compared with the previously published SIMS data and obtained the good agreements. In this paper the channeling behaviour of implanted impurity and the damage accumulation are analyzed and discussed in the simple 3D structure, named the Hole structure which has a rectangular implant window.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.10a
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• pp.755-756
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• 2012

• Journal of Periodontal and Implant Science
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• v.20 no.2
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• pp.169.2-169.2
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• 1990

• Journal of the Korean Ceramic Society
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• v.48 no.5
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• pp.390-395
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• 2011

The objective of our study was to produce an imitation bone material consisting of hydroxyapatite with a compact and spongy structure. This study shows the ideal content of $SiO_2$ and the sintering temperature to produce imitation bone that has the mechanical properties of natural bone. On the basis of our determination of the ideal conditions, a compact part was produced and its mechanical properties were tested. A compact part made of 0.5 wt% $SiO_2$ and sintered at $1350^{\circ}C$ showed excellent mechanical properties. The bioactivity of the compact part under this condition was tested, and it was found to be bioactive. The porous part was produced by controlling the powder size, and the dual structure was manufactured by combining the compact and porous parts. A water permeability test confirmed that the dual structure had an interconnected pore structure. Therefore, this dual-body structure is feasible for use in the creation of implants.