• The Journal of Korean Academy of Prosthodontics
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• v.55 no.3
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• pp.305-310
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• 2017

Nowadays, the development of dental scanner and CAD/CAM technology can facilitate the fabrication of hybrid prosthesis. Double scanning technique, scanning a trial prosthesis and master model, made it possible to realize virtual design and simplify the laboratory work. Instead of using the metal or zirconia framework with composite, ceramic or denture tooth, the new high performance polymer Polyetherketoneketone (Pekkton, Cendres+$M{\acute{e}}taux$, Biel, Switzerland) as a framework with Polymethyl methacrylate (PMMA) veneering teeth (Visio-lign, Bredent, Senden, Germany) was used in this case. This case report showed an acceptable treatment outcome and satisfaction of patient using Pekkton and Visio-lign. However, long term clinical evaluation is needed.

• Journal of Periodontal and Implant Science
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• v.29 no.1
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• pp.81-93
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• 1999

Non-surgical therapy is still an important technique in periodontal treatment. In this study, scaling and root planing(SRP) with or without concomitant subgingival curettage were compared clinically and microbiologically. 14 moderate adult periodontitis patients were included in this study. After 2 weeks from screening visit, with split mouth design, one quadrant was treated by SRP, and the opposite side was treated by SRP with subgingival curettage. Clinical measurement and microbiological analysis was taken at baseline, 1 month, 3 month post-treatment. Clinical parameters used in this study was probing depth, gingival recession, gingival index, bleeding on probing, plaque index, tooth mobility(Periotest Value). Microbiological analysis consisted of determination of the percentages of 4 bacterial groups according to morphologic type with phase-contrast microscope and measuring Black-pigmented Bacteroides after anaerobic culture. 1. There were significant changes in probing depth and gingival recession at 1 month(P<0.05), and these changes remained through 3 month. However, no significant differences were observed between two groups(P<0.05). 2. There were also significant reductions in gingival index and bleeding on probing at 1 month(P<0.05),and these reduced levels were maintained through 3 month with no significant differences between two groups(P<0.05). 3. In both groups, motile bacteria decreased significantly at 1 months(P<0.05), but increased nearly to baseline level at 3 month. 4. The percentages of Black-pigmented Bacteroides, in both groups, decreased significantly at 1 month(P<0.05), and in the subgingival curettage group, significant more reductions were observed than in the root planing group(P<0.05). At 3 month, significant reduction was found in subgingival curettage group only(P<0.05). According to these results, we surmised that concomitant subgingival curettage and root planing give some advantageous effect on bacterial recolonization.

• The korean journal of orthodontics
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• v.46 no.2
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• pp.111-126
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• 2016

Objective: To systematically review previous studies and to assess, via a subgroup meta-analysis, the combined odds ratio (OR) of prognostic factors affecting the success of miniscrew implants (MIs) inserted into the buccal posterior region. Methods: Three electronic searches that were limited to articles on clinical human studies using MIs that were published in English prior to March 2015 were conducted. The outcome measure was the success of MIs. Patient factors included age, sex, and jaw of insertion (maxilla vs. mandible), while the MI factors included length and diameter. A meta-analysis was performed on 17 individual studies. The quality of each study was assessed for non-randomized studies and quantified using the Newcastle-Ottawa Scale. The meta-analysis outcome was a combined OR. Subgroup and sensitivity analyses based on the study design, study quality, and sample size of miniscrews implanted were performed. Results: Significantly higher success rates were revealed for MIs inserted in the maxilla, for patients ${\geq}20$ years of age, and for long MIs (${\geq}8mm$) and MIs with a large diameter (> 1.4 mm). All subgroups acquired homogeneity, and the combined OR of the prospective studies (OR, 3.67; 95% confidence interval [CI], 2.10-6.44) was significantly higher in the maxilla than that in the retrospective studies (OR, 2.10; 95% CI, 1.60-2.74). Conclusions: When a treatment plan is made, these risk factors, i.e. jaw of insertion, age, MI length, and MI diameter, should be taken into account, while sex is not critical to the success of MIs.

• Journal of Periodontal and Implant Science
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• v.24 no.2
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• pp.421-432
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• 1994

The local route of antibiotic administration can accomplish higher therapeutic doses in subgingival sites than those possible by systemic therapy. This investigation assessed on the clinical and microbiological effect of 30% Minocycline loaded polycaprolactone film (Mino-strip) on rapidly progressive periodontitis. Mino-strip was applied in the periodontal pockets of 15 patients with clinically diagnosed as a rapidly progressive periodontitis. 8sites for each patient with a 5mm probing pocket depth were selected in split mouth design and were assigned into group. i.e., placebo(group 1), supragingival scaling and R/P(group 2), Mino-strip applied only(group 3), R/P and Mino-strip applied(group 4). Supragingival scaling and oral hygiene instruction were performed 1 wk before experiment. Mino-strip was applied weekly on day 0 and 7. Clinical and microbiological test were performed on day 0, 7, 14, 28, 56. In R/P and Mino-strip applied group, Gingival index, GCF volume, probing depth and loss of attachment level were significantly reduced after the first weeks following treatment. In R/P and Mino-strip applied group, the relative proportions of spirochetes and motile rods were significantly reduced and the proportions of cocci and non motile rod were correspondingly increased for eight weeks following treatment. In R/P and Mino-strip treated group, total anaerobic and aerobic bacterial count were significantly decreased for the first two weeks following treatment and streptococcus count was decreased for eight weeks following treatment. In R/P and Mino-strip applied group, P. gingivalis, P. intermedius, B. forsythus, A. actinomycetemcomitans, F. nucleatum, E. corrodens, C. rectus counts were significantly reduced after the first week following treatment. According to this study, it is appeared that 30% Minocycline-loaded polycaprolacton film was effective in the treatment on rapidly progressive periodontitis.

• The Journal of the Korea Contents Association
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• v.13 no.3
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• pp.22-31
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• 2013

For the case of test equipments requiring data accuracy, real-time is highly required in acceptance test for performance evaluation of developed weapons. For convenience' sake, test equipments are usually developed using Windows. However Windows does not support real-time in itself. Thus, in this paper, so as to reduce development time and expenses, we design and implement an integrated middleware for real-time device drivers using RTiK-MP. Using DLL, we also support user API's for the sake of development convenience without details of the complex RTiK-MP structure. We evaluate the performance of the proposed integrated middleware using the RDTSC command which returns the number of CPU clock ticks. The evaluation results show that it operates correctly within error ranges in the periods of 1ms and 4ms for the cases of TCP/IP and RS-232, respectively.

• Proceedings of the KOSOMBE Conference
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• v.1994 no.12
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• pp.71-74
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• 1994

In cementless total hip arthroplasty(THA), an initial stability of the femoral component is mandatory to achieve bony ingrowth and secondary long term fixation. Bone ingrowth depends strongly on relative micromotion and stress distributions at the interface. Primary stability of the femoral component can be obtained by minimizing the magnitude of relative micromotions at bone-prosthesis interface, Hence an accurate evaluation of interface behavior and stress/strain fields in the bone implant system may be relevant for better understanding of clinical situations and improving THA design. However, complete evaluation of load transfer in the bone remains difficult to assess experimentally, Hence, recently finite element method (FEM) was introduced in orthopaedic research field to fill the gap due to its unique capacity to evaluate stress in structure of complex shape, loading and material behavior. The authors developed the 3-dimensional numerical finite element model which is composed of totally 1179 elements off and 8 node blick. We also analyzed the micromotions at the bone-stem interface and mechanical behavior of existing bone prosthesis for a loading condition simulating the single leg stance. The result indicates that the values of relative motion for this well fit Multilock stem were $150{\mu}m$ in maximum, $82{\mu}m$ in minimum, and the largest relative motion developed in medial region of proximal femur with anterior-posterior direction. The proximal region of the bone was much larger in motion than the distal region and the stress pattern shows high stress concentration on the cortex near the tip of the stem. These findings indicates that the loading in the proximal femoral bone in the early postoperative situation can produce micromotions on the interface and clinically cementless TEA patient should not be allowed weight bearing strictly early in the postoperative period.

• Journal of Periodontal and Implant Science
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• v.39 no.sup2
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• pp.261-268
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• 2009

Purpose: To estimate the prevalence of periodontitis in Korean adults and to examine the associations between periodontitis and known risk factors. Methods: Using Korean National Oral Health Survey 2006 data, a total of 4,263 people who had taken oral examination, interviewed by questionnaire, and aged 18 or older were sampled. The prevalence of periodontitis measured by Community Periodontal Index (CPI) was calculated and the differences in prevalence according to known risk factors (age, sex, monthly income, education, residential area, tooth-brushing frequency, regular dental visit, smoking, and diabetes) were examined with chi-square test. Logistic regression analysis was performed to see the effects of each risk factor on the risk of having periodontitis. All statistical approaches were reflected national sampling design using Survey procedures in SAS 9.1. Results: The overall prevalence of periodontitis in Korean adults was 10.3%. There existed statistically significant differences in crude prevalence for periodontitis according to the all risk factors. In logistic regression, older age groups (O.R.:2.94-3.71), people living in rural area (O.R.:1.87), and current smokers (O.R.:1.77) were significantly prone to have periodontitis. People who earned monthly income of more than 2 million Korean won (O.R.:0.64) and brushed their teeth two or more times per day (O.R.:0.60-0.62) had significantly lower risk of having periodontitis. Conclusions: About 10% of Korean adults had periodontitis in 2006. People who were older, living in rural region, in lower income status, smoking, less tooth brushing were more likely to have periodontitis.

• The Journal of Advanced Prosthodontics
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• v.9 no.5
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• pp.381-386
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• 2017

PURPOSE. To integrate extra-oral facial scanning information with CAD/CAM complete dentures to immediately rehabilitate terminal dentition. MATERIALS AND METHODS. Ten patients with terminal dentition scheduled for total extraction and immediate denture placement were recruited for this study. The patients were submitted to a facial scanning procedure using the in-office PritiMirror scanner with bite registration records in-situ. Definitive stone cast models and bite records were subsequently submitted to a lab scanning procedure using the lab scanner (iSeries DWOS; Dental Wings). The scanned models were used to create a virtual teeth setup of a complete denture. Using the intra-oral bite records as a reference, the virtual setup was incorporated in the facial scan thereby facilitating a virtual clinical evaluation (teeth try-in) phase. After applying necessary adjustments, the virtual setup was submitted to a CAM procedure where a 5-axis industrial milling machine (M7 CNC; Darton AG General) was used to fabricate a full-milled PMMA immediate provisional prosthesis. RESULTS. Total extractions were performed, the dentures were immediately inserted, and subjective clinical fit was evaluated. The immediate provisional prostheses were inserted and clinical fit, occlusion/articulation, and esthetics were subjectively assessed; the results were deemed satisfactory. All provisional prostheses remained three months in function with no notable technical complications. CONCLUSION. Ten patients with terminal dentition were treated using a complete digital approach to fabricate complete dentures using CAD/CAM technology. The proposed technique has the potential to accelerate the rehabilitation procedure starting from immediate denture to final implant-supported prosthesis leading to more predictable functional and aesthetics outcomes.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.368-368
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• 2008

Ion implantation has been widely developed during the past decades to become a standard industrial tool. To comply with the growing needs in ion implantation, innovative technology for the control of ion beam parameters is required. Beam current, beam profile, ion fractions are of great interest when uniformity of the implant is an issue. Especially, it is important to measure the spatial distribution of beam power and also the energy distribution of accelerated ions. This energy distribution is influenced by the proportion of mass for ion in the plasma generator(ion source) and by charge exchange and dissociation within the accelerator structure and also by possible collective effects in the neutralizer which may affect the energy and divergence of ions. Hydrogen atom has been the object of a good study to investigate the energy distribution. Hydrogen ion sources typically produce multi-momentum beams consisting of atomic ion ($H^+$) and molecular ion ($H_2^+$ and $H_3^+$). In the beam injector, the molecular ions pass through a charge-exchanges gas cell and break up into atomic with one-half (from $H_2^+$) or one-third (from $H_3^+$) according to their accelerated energy. Burrell et al. have observed the Doppler shifted lines from incident $H^+$, $H_2^+$, and $H_3^+$ using a Doppler shift spectroscopy. Several authors have measured the proportion of mass for hydrogen ion and deuterium using an ion source equipped with a magnetic dipole filter. We developed an ion implanter with 50-KeV and 20-mA ion source and 100-keV accelerator tube, aiming at commercial uses. In order to measure the proportion of mass for ions, we designed a filter system which can be used to measure the ion fraction in any type of ion source. The hydrogen and helium ion species compositions are used a filter system with the two magnets configurations.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.48 no.5
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• pp.74-80
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• 2011

Medical implant devices are one of the targets of the US's Food & Drug Administration (FDA) for tracking in case of a serious adverse event since they are directly connected to the lives of patients. The US law stipulates that the public health agency shall order implantable device makers to track their product down to the patient level if a serious adverse event has occurred or defects have been discovered; in reality, however, the agency can pass on the responsibility for tracking or recalling faulty devices to the manufacturers or use mass media. This article proposes an efficient tracking and recall management system and examines four main virtual scenarios based on such. This research seeks to suggest a system that enables FDA to perform accurate and prompt tracking and recall management for patients' enhanced safety.