• The Journal of Korean Academy of Prosthodontics
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• v.58 no.1
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• pp.42-49
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• 2020

In patients with fully edentulous jaw, treatment of complete dentures should be carried out in many stages when following the conventional methods. Therefore there were disadvantages such as multiple visits to dental clinic is inevitable. In addition, errors caused by polymerization shrinkage, which happens during the fabrication of denture, and difficulties in reproduction of damaged or lost denture were considered as disadvantages. But nowadays, computer-aided design and computer-aided manufacturing (CAD/CAM) system is widely used in dentistry and it has begun to expand its spectrum in manufacturing complete dentures. Using CAD/CAM system to fabricate complete dentures can reduce the number of patient's visit and clinical chair time, since taking impression, recording jaw relation, and selection of artificial teeth are performed at the same time during the first visit, and delivering of dentures during the second visit is possible. In addition, because 3D-Printing technology is used, errors by polymerization shrinkage can be reduced. Among the companies that fabricate complete dentures using CAD/CAM system, DENTCA CAD/CAM denture (DENTCA Inc., Los Angeles, CA, USA) is the most commercialized company. In this case, we treated patients of complete dentures using conventional complete denture method and DENTCA CAD/CAM denture system in the same patient. We would like to report this case because we have achieved good results not only in functional aspects of pronunciation, chewing, and swallowing but also in aesthetic aspects.

• Journal of Life Science
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• v.27 no.3
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• pp.351-354
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• 2017

Cowpea (Vigna unguiculata (L.) Walp.) is recognized as a potential source of protein and other nutrients. The genus Vigna includes 100 wild species of plants. Especially, Vigna unguiculata includes annual cowpeas (ssp. unguiculata) and ten wild perennial subspecies. DNA sequence of internal transcribed spacer (ITS) region was determined for Vigna sinensis, one of native plant, which was found in recent but thought to have gone extinct in Korea. The seeds of Vigna sinensis used in this study were donated from Dong-Young Jo. The DNA sequence of ITS-5.8S-ITS2 for Vigna sinensis obtained from this study was deposited as Vigna sinensis AY195581 on GenBank of NCBI (National Center for Biotechnology Information). We investigated the sequence-based phylogenetic relationships of plants related and clarified its taxonomical position. DNA similarities among subspecies including Vigna unguiculata showed the range 98 to 100% in sequence-based phylogenetic analysis using total 507 base pairs of ITS1, 5.8S and ITS2. Vigna unguiculata and subspecies were grouped independently as one cluster from other Vigna species used in the phylogenetic analysis. In this study, based on the phylogenetic analysis using the ITS1-5.8S-ITS2 sequence of Vigna sinensis, it may be concluded to be classified to one of Vigna unguiculata substrains.

• Journal of Marine Bioscience and Biotechnology
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• v.7 no.2
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• pp.58-70
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• 2015

Injectable RGD-bioconjugated Mussel Adhesive Proteins (RGD-MAPs) composite hydroxypropyl methylcellulose (HPMC) hydrogels provide local periodontal tissue for bone filling in periodontal surgery. Previously we developed a novel type of injectable self-supported hydrogel (2 mg/ml of RGD-MAPs/HPMC) based porcine nano hydroxyapatite (MPH) for dental graft, which could good handling property, biodegradation or biocompatibility with the hydrogel disassembly and provided efficient cell adhesion activity and no inflammatory responses. Herein, the aim of this work was to evaluate bone formation following implantation of MPH and collagen membrane in rabbit calvarial defects. Eight male New Zealand rabbits were used and four circular calvarial defects were created on each animal. Defects were filled with different graft materials: 1) collagen membrane, 2) collagen membrane with MPH, 3) collagen membrane with bovine bone hydroxyapatite (BBH), and 4) control. The animals were sacrificed after 2 and 8 weeks of healing periods for histologic analysis. Both sites receiving MPH and BBH showed statistically increased augmented volume and new bone formation (p < 0.05). However, there was no statistical difference in new bone formation between the MPH, BBH and collagen membrane group at all healing periods. Within the limits of this study, collagen membrane with MPH was an effective material for bone formation and space maintaining in rabbit calvarial defects.

• Journal of the Korean Society of Radiology
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• v.12 no.1
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• pp.53-64
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• 2018

Using the AUDIT-K (Korean versions of alcohol use disorders identification test), it was able to select a large number of potential danger drinkers who routinely live. There were no statistically significant differences in age, religion, marital status, occupation, family history of alcohol drinking, age at onset of alcohol use, smoking, and BMI (body mass index). However, only education and drinking periods were statistically significant. These results are consistent with the previous study, which suggests that alcohol consumption is higher among men who are educated. The level of education also suggests that there is a need to look at the differences depending on what you learned and how. Alcohol consumption by education also shows different results. Also, drinking at a young age will lead to a longer drinking period, which is consistent with previous studies on the age at onset of drinking. In this study, drinking period was the most important factor of alcohol use disorder and it is considered that measures and education of national government system which can delay drinking age as much as possible is needed as a method to shorten drinking period.

• Journal of Technologic Dentistry
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• v.33 no.4
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• pp.349-357
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• 2011

Purpose: In this study, for the reasons of observing the changes when using bonding agent with Ni-Cr alloy and Co-Cr alloy and using VM13 and Vintage MP ceramic which have the disparity in coefficient of thermal expansion, it is carried out to evaluate the characteristics of the bonding agent through the analysis of the interface between metal and ceramic and the analysis of bond strength by variable. Methods: The surface treatment was performed on the two kinds of alloy(Ni-Cr alloy and Co-Cr alloy) specimens, which were sandblasted and were treated with bonder application. The metal-ceramic interfaces were analyzed with EPMA in order to ionic diffusion, and the shear test was performed. Results: As a result of observation of metal-ceramic interfacial properties, it was observed that Cr atoms were spread from the alloy body to the ceramic floor in the specimen of Group B. It was also seen that Cr, W atoms were spread from the alloy body to the ceramic floor in the specimen of Group S. In consequence of observing Shear bond strength, it was calculated that the specimen of BSV was 27.75(${\pm}11.21$)MPa, BSM was 27.02(${\pm}5.23$)MPa, BCV was 30.20(${\pm}5.99$)MPa, BCM was 27.94(${\pm}10.76$)MPa, SSV was 20.83(${\pm}2.58$)MPa, SSM was 23.98(${\pm}3.94$)MPa, SCV was 32.32(${\pm}4.68$)MPa, and SCM was 34.54(${\pm}10.63$)MPa. Conclusion: In the metal-ceramic interface of Bellabond plus sample group, diffusion of Cr atoms was incurred and diffusion of C Cr atoms and W atoms in the sample group of $Starloy{(R)}\;C$ was observed. Using bonding agent showed the higher bond strength than using the sand blasting treatment. In the Bellabond plus alloys, the specimen group with the use of binding materials showed higher shear bond strength, but didn't show statistically significant differences (p>0.05). In the $Starloy{(R)}\;C$ alloys, the specimen group with the use of binding materials showed higher shear bond strength and statistically significant differences(p<0.05). In terms of VM13 ceramic, it was in the Bellabond plus alloys that the high shear bond strength was showed, but there's no statistically significant differences(p>0.05). In terms of Vintage MP ceramic, it was in the $Starloy{(R)}\;C$ alloys that the high shear bond strength was showed and statistically significant differences(p<0.05). Metal-ceramic to fracture of the shear strength measurements and an analysis of all aspects of military usage fracture of the composite, respectively.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.6
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• pp.493-499
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• 2018

This study was conducted to investigate the mediating effects of walking days on body mass index (BMI) according to the public transportation satisfaction of middle aged Koreans aged 40-59 in Korea using the 2015 community health survey data. The purpose of this study was to provide basic data for provision of the neighborhood environment and support programs for the walking activity and promotion of daily walking activities among middle aged people. Among 228,558 individuals, 85,344 middle aged people aged 40-59 years were selected as final subjects for analysis. The data were analyzed with the open source statistics program R 3.4.1 to determine whether the number of walking days had a mediating effect on body mass index (BMI) as an independent variable. The Sobel test revealed that the number of walking days increased by B=0.010(p=.010), and that when the satisfaction with public transportation increased, B=-0.052 (p=.021), the number of walking days decreased by B=-0.038 (p=.001). To increase the number of walking days and decrease the body mass index by increasing public transportation satisfaction by increasing the use of public transportation, public transportation fare adequacy and access convenience among the public transportation satisfaction mentioned above should be improved more than the current level. It is not easy for individuals that live in small cities to reach their destination by public transportation after leaving the metropolitan area; therefore, improvement of public transportation systems is necessary to improve health.

• Journal of Oral Medicine and Pain
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• v.36 no.1
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• pp.25-37
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• 2011

The purpose of this study is to investigate the relationship between personality type and symptoms and contributing factors of temporomandibular disorders. 199 college students completed the MBTI(Myers-Briggs Type Indicator) and a questionnaire and collected data were analyzed by SAS 9.2 program. The obtained results were as follows : 1. The prevalence of symptoms of temporomandibular disorders and mean scales of positive answers of contributing factors appeared to be higher in I type, S type, T type, P type than in E type, N type, F type, J type. 2. ISTP and ISFP among 16 types of personality seemed to have higher prevalence of symptoms and contributing factors of temporomandibular disorders than other types of personality. 3. Symptom of TMJ pain during mouth opening seemed to occur more frequently in I type, S type, F type, J type than in E type, N type, T type, P type. 4. Contributing factors including clenching and stressful state occurred significantly more frequently in I type than E type. Gum chewing habit occurred significantly more frequently in E type than in I type. 5. Unilateral chewing habit occurred significantly more frequently in J type than in P type. 6. Nervous or sensitive persons had significantly higher mean scales of positive answers of subjective symptoms than relaxed or general persons. 7. General persons had significantly lower mean scales of positive answers of contributing factors than nervous, sensitive and relaxed persons. In conclusion, these results show that there is the relationship between personality and temporomandibular disorders and patient education and counselling considering personality type may contribute to treating patients with temporomandibular disorders.

• Journal of radiological science and technology
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• v.39 no.4
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• pp.543-547
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• 2016

Acute stroke is a one of common disease that require fast diagnosis and treatment to save patients life. however, the acute stroke may cause lifelong disability due to brain damage with no prompt surgical procedure. In order to diagnose the Stroke, brain perfusion CT examination and possible rapid implementation of 3D angiography has been widely used. However, a low-dose technique should be applied for the examination since a lot of radiation exposure to the patient may cause secondary damage for the patients. Therefore, the degradation of the measured CT images may interferes with a clinical check in that blood vessel shapes on the CT image are significantly affected by gaussian noise. In this study, we employed the spatio-temporal technique to analyze dynamic (brain perfusion) CT data to improve an image quality for successful clinical diagnosis. As a results, proposed technique could remove gaussian noise successfully, demonstrated a possibility of new image segmentation technique for CT angiography. Qualitative evaluation was conducted by skilled radiological technologists, indicated significant quality improvement of dynamic CT images. the proposed technique will be useful tools as a clinical application for brain perfusion CT examination.

• Journal of Life Science
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• v.22 no.8
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• pp.1071-1076
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• 2012

To investigate the antimicrobial and anti-halitosis effects of Alnus firma extracts and gallic acid (GA) isolated from A. firma, we measured their antimicrobial activities against oral pathogens and their inhibitory effects on the cell adhesiveness and acid production of oral pathogens. In addition, the levels of volatile sulfur compounds were determined by using oral chroma. The dichloromethane (DCM) fraction has broad antimicrobial activity, and the ethylacetate (EA) fraction showed a relatively high level of antimicrobial activity against Streptococcus mutans and Porphyromons gingivalis. Especially, the GA and DCM fractions had significant inhibitory effects on the attachment and acid production of S. mutans and Streptococcus salivarius, respectively. The 2% MeOH extract of A. firma showed a significant inhibitory effect on the production of volatile oral compounds, such as hydrogen sulfide, methyl mercaptan, and dimethyl sulfide, which can cause bad breath and halitosis. Two percent GA also had a significant inhibitory effect on the production of hydrogen sulfide. Our study showed that the active fractions and GA of A. firma could be suitable resources for development as a natural antibiotic agent for the treatment of infectious oral diseases.

• Korean Journal of Materials Research
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• v.14 no.12
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• pp.893-899
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• 2004

Even though Ti-6Al-4V has gained popularity as an implant material, the possible dissolution of Al and V ions in body fluids remains a matter of concern. Though commercially pure Ti (Cp-Ti) overcomes this problem, the mechanical strength of pure titanium remains very low. Thus, in this experiment Cp-Ti was processed by Equal channel angular processing (ECAP), in order to increase the mechanical strength. The biocompatibility of ECAP-Ti, Cp-Ti and Ti-6Al-4V was examined by the apatite formation on each sample surface, after treating the surface with 5M NaOH and soaking in Simulated body fluids (SBF). Initially, the samples were mechanically polished on silicone carbide paper (#2000). The polished samples were treated with 5M NaOH solution at $60^{\circ}C$ for 24 hours. The NaOH treated samples were washed gently with distill water and dried at $40^{\circ}C$ for 1 day. The dried samples were heat treated in air at $600^{\circ}C$ for 1 hour. The surface morphology of these samples were studied using SEM and XRD. The SEM studies showed network of pores in all samples. The XRD showed oxide layer formation on Cp-Ti and Ti-6Al-4V. samples. However the oxide layer in ECAP-Ti was not substantial. These samples were immersed in SBF, kept at $36.5^{\circ}C$ for seven days period. At the end of 7 days, the apatite formation was confirmed only on Cp-Ti and was not observed in Ti-6Al-4V and ECAP-Ti. These observations of apatite formation relate to the fact that Cp-Ti showed greater oxide layer than other samples. The apatite examined was confirmed as tricalcium phosphate (TCP) using EDS and XRD.