• Journal of Periodontal and Implant Science
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• v.53 no.3
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• pp.218-232
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• 2023

Purpose: This study evaluated the efficacy of a tube-shaped poly(ε) caprolactone - β tricalcium phosphate (PCL-TCP) scaffold with the incorporation of human umbilical cord-derived mesenchymal stem cells (hUCMSCs) and platelet-rich plasma (PRP) for bone regeneration in the procedure of single-stage sinus augmentation and dental implantation in minipigs. Methods: Implants were placed in the bilateral sides of the maxillary sinuses of 5 minipigs and allocated to a PCL-TCP+hUCMSCs+PRP group (n=5), a PCL-TCP+PRP group (n=5), and a PCL-TCP-only group (n=6). After 12 weeks, bone regeneration was evaluated with soft X-rays, micro-computed tomography, fluorescence microscopy, and histomorphometric analysis. Results: Four implants failed (2 each in the PCL-TCP+hUCMSCs+PRP and PCLTCP+hUCMSC groups). An analysis of the grayscale levels and bone-implant contact ratio showed significantly higher mean values in the PCL-TCP+hUCMSCs+PRP than in the PCL-TCP group (P=0.045 and P=0.016, respectively). In fluoromicroscopic images, new bone formation around the outer surfaces of the scaffolds was observed in the PCLTCP+hUCMSCs+PRP group, suggesting a tenting effect of the specially designed scaffolds. Bone regeneration at the scaffold-implant interfaces was observed in all 3 groups. Conclusions: Using a tube-shaped, honeycombed PCL-TCP scaffold with hUCMSCs and PRP may serve to enhance bone formation and dental implants' osseointegration in the procedure of simultaneous sinus lifting and dental implantation.

• Applied Chemistry for Engineering
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• v.16 no.1
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• pp.117-122
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• 2005

The aim of this study was to evaluate the effect of tertiary amine photo-accelerator on the dental properties of visible light-activated, polymeric, dental restorative composites (PDRC) through the measurement of mechanical and esthetic properties. The surface of barium silicate was hydrophobically treated to improve the interfacial behavior with the acrylic resin matrix. Camphorquinone was adopted as a photo-initiator with 0.5 wt% based on the resin matrix. It was discovered that the dental properties of PDRC were primarily dependent on the chemical structure rather than the added content of photo-accelerator.

• Journal of Technologic Dentistry
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• v.33 no.3
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• pp.211-218
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• 2011

Purpose: The purpose of the study was a quantitative evaluation of common errors in digital impression procedure using CEREC$^{(R)}$ AC system. Methods: Two-hundreds digital impression data comprising 174 inlays, 26 onlays by CEREC$^{(R)}$ AC in-office CAD/CAM system were obtained from a dental clinic. One evaluator assessed errors of the digital impression data and divided into five categories of errors: inappropriate scanner positioning (ISP), improper handling with a scanner (IHS), irregular powder arrangement (IPA), improper cavity preparation (ICP), and insufficient scanned data (ISD). Results: The most common errors were IPA(21%), and ISP and ISD were followed by 17% respectively. IHS was found in 14.5% of all digital impression data. ICP comprising only 6.5% was the rarest. Conclusion: Most errors were due to inaccurate manipulation with an intraoral scanner or improper cavity preparation for scanning. A deliberate manipulation to prevent common errors mentioned may deliver an optimal result in the digital impression procedure.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2013.05a
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• pp.219-220
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• 2013

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2007.06a
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• pp.7-8
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• 2007

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2015.05a
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• pp.64-64
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• 2015

• Journal of dental hygiene science
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• v.11 no.2
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• pp.63-67
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• 2011

This study aimed to propose appropriate methods of statistical analysis and interpretation of survey results in dental hygiene. By using examples of published articles in the Journal of Dental Hygiene Science from 2003 to 2008, we made some suggestions to improve scientific and clear writing of the contents; purpose of the study, subjects and methods, statistical analysis, tables, and interpretations.

• Journal of Technologic Dentistry
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• v.40 no.2
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• pp.73-82
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• 2018

Purpose: The purpose of this study was to investigate the production environment of crown prosthesis for National Health Insurance(NHI) benefit. Methods: This study carried out self-administered questionnaire survey from September 1, 2016 to October 31 by having research subjects as 261 dental technician. Except 100 copies with incomplete response, 161 copies were used as the materials of final analysis. Results: Unlike gold crowns, the material cost of metal crowns was paid at the dental laboratory(86.3%). Total material consumption for making metal crown was more than gold crown(63.4%), especially for the finishing and polishing processes(78.3%). The subjects responded that a routine dental laboratory fee of crown prosthesis is unreasonable, and it is necessary to adjust and improve it(metal crown 96.2%, gold crown 96.9%). NHI coverage dental prosthesis was not marked on the order form(46.0%), and the dental laboratory fee of that was nor received(64.0%). Conclusion : It is necessary to estimate the NHI cost level of the crown prosthesis by reflecting the production environment and engineering process in dental laboratories. In addition, institutional arrangement should be backed up so that dental laboratories can receive appropriate dental laboratory fee.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.25 no.5
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• pp.421-432
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• 2012

This paper is the first paper among two papers which constitute the paper about the structural design of a dental implant. This paper surveyed types and characteristics of dental implants. Merits and shortcomings of clinically used dental implants were analysed through this survey. A new structural model of dental implant was proposed on the basis of survey results. Especially, a comparative structural analysis of the new dental implant and the well known dental implants has been performed using the finite element analysis method. The analysis results confirm that the newly proposed dental implant has a good structural performance. The well known dental implants used for the comparative structural analysis are 3i implant and Sargon implant. These implants are imported dental implants and we could know that most implants clinically used are endosteal implants and these two implants(3i implant and Sargon implant) are also endosteal implants.

• Journal of Technologic Dentistry
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• v.39 no.1
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• pp.1-7
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• 2017

Purpose: The purpose of this in vitro study compared to evaluation of repeatability of scanning abutment tooth stone model and impression applied CAD/CAM ISO standard in dentistry. Methods: To evaluate repeatability of scanning abutment tooth stone model, were repeatedly scanned to obtain 11 data via 3D stereolithography (STL) files. 10 data (STL files) were compared with the first 3D data (STL file), and the error sizes were measured by using 3D superimposing software(n=10). Also, the repeatability of scanning abutment tooth impression was evaluated with the same procedure. Independent t test was performed to evaluate the repeatability of scanning abutment tooth stone model versus impression through root mean square(RMS) and standard deviation(SD)(${\alpha}=0.05$). Results: $RMS{\pm}SD$ with regard to repeatability were $14.7{\pm}2.5{\mu}m$, $17.1{\pm}4.0{\mu}m$, respectively, with scanning abutment tooth stone model and impression(p=0.129). Conclusion: This study results showed a little different repeatability of scanning abutment tooth stone model and impression applied CAD/CAM ISO standard in dentistry, will suggest futures good studies and clinical advantages.