• Journal of the Korean Institute of Telematics and Electronics D
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• v.36D no.3
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• pp.27-33
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• 1999

We have investigated the ultra-low energy B, P, and As ion implantation using upgraded MDRANGE code to study formation of nanometer junction depths. Even at the ultra-low energies simulated in this paper, it was revealed that ion channeling should be carefully considered. It was estimated that ion channelings have much effect on dopant profiles when B ion implant energies were more than 500 eV, P more than 2 keV and As approximately more than 4 keV. When we compared 2-dimensional dopant profiles of 1 keV B with that of tilted one, 2 keV P with tilt, and 5 keV As with tilt, we could find that most channeling cases occurred not lateral directions but depth directions.

• The Journal of Korean Academy of Prosthodontics
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• v.51 no.2
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• pp.113-118
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• 2013

When losing many of the remaining teeth, the relation among them can be put into dynamically unfavorable situation. In the case that the patient without any incompatibilityto the denture, overdenture can be considered. Moreover, we can overcome the dynamical disadvantage, and improve the support, stability, and retention of the partial denture by using implant at the edentulous area. In this case, patient with crossed occlusion between few remaining teeth was treated with maxillary and mandibular partial denture. Single implant fixture was placed at the edentulous space, opposing to the maxillary teeth occluded, and $Locator^{(R)}$ attachment was connected. The patient's esthetic satisfaction was improved by ideally adjusting the tilted occlusal plane. Since the patient was satisfied both esthetically and functionally, and maintained stable during the clinical observation for 6 months after the treatment, we would like to report about it.

• The Journal of Korean Academy of Prosthodontics
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• v.54 no.2
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• pp.110-119
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• 2016

Purpose: This study is aimed to assess changes of stress distribution dependent on different connection lengths and placement of the fixture top relative to the ridge crest. Materials and methods: The internal-conical connection implant which has a hexagonal anti-rotation index was used for FEM analysis on stress distribution in accordance with connection length of fixture-abutment. Different connection lengths of 2.5 mm, 3.5 mm, and 4.5 mm were designed respectively with the top of the fixture flush with residual ridge crest level, or 2 mm above. Therefore, a total of 6 models were made for the FEM analysis. The load was 170 N and 30-degree tilted. Results: In all cases, the maximum von Mises stress was located adjacent to the top portion of the fixture and ridge crest in the bone. The longer the connection length was, the lower the maximum von Mises stress was in the fixture, abutment, screw and bone. The reduction rate of the maximum von Mises stress depending on increased connection length was greater in the case of the fixture top at 2 mm above the ridge crest versus flush with the ridge crest. Conclusion: It was found that the longer the connection length, the lower the maximum von Mises stress appears. Furthermore, it will help prevent mechanical or biological complications of implants.