• The korean journal of orthodontics
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• v.40 no.4
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• pp.267-275
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• 2010

Objective: The aim of this study was to evaluate and compare the shear bond strength (SBS) and failure-mode of orthodontic buttons bonded to erupted and unerupted teeth with conventional and self-etching adhesive systems. Methods: Eighty-four erupted and 84 unerupted, human third-molar teeth were used. For both groups, the buccal surfaces of each tooth were assigned one of the following type of adhesive systems (n = 12). A, Conventional systems: 1, Transbond XT (3M Unitek, Monrovia, CA, USA); 2, Prime & Bond NT (Dentsply/Caulk, Milford, USA); 3, Single Bond (3M ESPE, Minnesota, USA); and B, Self-etching adhesives; 4, Clearfil SE Bond (Kuraray, Okayama, Japan); 5, Transbond Plus (3M Unitek, Monrovia, CA, USA); 6, Clearfil S3 (Kuraray, Tokyo, Japan); 7, G Bond (GC, Tokyo, Japan). The SBSs of the attachments and the adhesive remnant index (ARI) scores were recorded. Data were analyzed with analysis of variance (ANOVA), independent-sample t-test and chi-square tests. Results: When the SBSs of erupted and unerupted teeth were compared, only the Clearfil-SE Bond and G-Bond were significantly different. Bond strengths of all adhesive systems were higher in unerupted teeth than erupted teeth, except the Single-Bond system. Conclusions: When using conventional adhesives, bonding to erupted and unerupted teeth may not be significantly different. However, clinicians need to take into consideration the types of self-etching systems before usage.

• The Journal of the Korea Contents Association
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• v.17 no.7
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• pp.303-319
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• 2017

This study was to explore ex-offender's social readjustment based on the perceptions of correctional professionals and correctional counselors. For the study, 10 correctional professionals were interviewed including university professors majoring in criminology, judges of family court, various correctional workers and 8 correctional counselors responsible for counseling of ex-offender's in the Korea Rehabilitation Agency. The interviews were analyzed using content analysis procedures proposed by Krippendorff(2003). The results were composed of 5 spheres, 15 dimensions, 36 categories, and 77 meaning contents. With regard to social readjustment experiences of ex-offender's, domains such as 'education', 'psychotherapy', 'employment and job search', 'service, culture and leisure', and 'social and national support' were drawn from the analyses. Based on the results of this study, significance and implications were presented.

• Journal of Plant Biotechnology
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• v.46 no.3
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• pp.137-142
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• 2019

Gene edited crops can be classified as SDN-1, SDN-2 and SDN-3 group depending on their mutation's range and the usage of donor DNA. The SDN-1 and SDN-2 crops, in particular, could be developed as 100% transgene-free, which do not contain any DNA fragment of the vector or guide RNA used for gene editing such as CRISPR Cas9 system. Therefore, there are no scientific methods available for the detection of these crops and differentiation with the one produced by conventional cross breeding techniques. Additionally, it would be impossible to properly implement the existing GMO regulation law, in particular, the national legislation for "GMO labelling". In this regard, Australia has announced that SDN-1 crops will not be subjected to the existing GMO regulation. Furthermore, Argentina and Brazil have established a new policy that GE crops with no transgene (100% transgene-free crops) should be exempted from the scope of the GMO. In addition, Japan has also announced that "an organism that has no remnants of inserted nucleic acid processed extracellularly is not subjected to the Cartagena Act". It means that SDN-2 crops can also be exempted from the scope of GMO. In this trend, in South Korea, I suggested that gene edited crops with no remnants of inserted foreign DNA fragments should be excluded from the existing GMO regulation. Thus, I expect that diverse elite crop lines should be developed by using advanced gene editing technologies

• Proceedings of the Materials Research Society of Korea Conference
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• 2009.11a
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• pp.6.1-6.1
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• 2009

신경외과는 뇌수술과 척추수술로 나눈다. 이중뇌수술 분야에서는 두개강내압 항진시 감압술이라고 '머리의 뚜껑을 연다'라는 표현과 마찬가지로 두개골의 일부분(손바닥크기)을 절제하는 수술이 있다. 이때 과거에는 떼어낸 뼈를 복부의 피하지방밑에 심어서 보관을 하다가 3-6개월 후 환자의 뇌상태가 안정이 되면 다시 꺼내어 제자리에 놓았는데, 골편이 피하지방에서 녹는 경우가 다소 있고, 복부에 이식한 장소가염증이 생기는 경우도 있어서 요즘은 냉동고에서 -70도를 유지하여 보관 후 나중이 복원 수술을 할 때녹여서 사용한다. 이를 '자가골 두개성형술' 이라 한다. 하지만골편의 오염이나 소실 혹은 1차 두개성형술 후 감염 등 어쩔 수 없이 자가골을 사용 못하는 경우에는인공으로 두개골편 모형을 제작하여 '뚜껑'으로 사용해야 한다. 현재PMMA를 이용하여 수술 시 모형을 제작하는 방법이 많이 사용되며 최근 단단한 스펀지 형태의 인공제품이 사용되고 있으나 가격이 매우비싸지만 스펀지 기공내로 자가골이 자란다는 장점이 있다. 척추수술 분야에서는 뼈 대치품을 비교적 많이필요로 한다. 즉 척추 후방고정을 하는 경우 원래 수술의 목적인 감압술이나 교정술 등을 한 후 척추분절간 쇠(티타늄사용)고정을 한 뒤에 뼈조직(자가골이나 동종이식골, DBM, HA stick) 등을 충분히 사용하여덮어줌으로써 분절간 골유합을 유도할 때 많은 양이 필요하며, 척추 전방으로 수술을 하는 경우에도 디스크공간이 빈 상태에서 Cage(추체와 추체를 지지하는 작은 상자모양) 내에뼈조직을 넣어서 척추분절간 골유합이 일어나도록 한다. 최근 HA를 cage 대용품으로 사용한 경우에서 HA가 부서지는 경우가 기사화된바 있다. 또한 경추의 추체 내에 작은 구멍만 뚫고 디스크 수술을 한 후에 그 구멍에 HA+B-TCP 소재를 넣어 천연뼈의 성장 유도를 위해 사용되는 등 신경외과의 다양한 분야에서 생체소재들이 사용되고 있다.

• Journal of the korean academy of Pediatric Dentistry
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• v.26 no.2
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• pp.296-309
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• 1999

Autopolymerized resin facilitates a more rapid and easier means for the construction of removable orthodontic appliances than heat cured resin. But many reports reveal that more unreacted monomer is found in autopolymerized resin. It is very important to achieve maximum degree of polymerization because if polymerization is inadequate, high level of unreacted monomer has been shown to adversely affect mechanical and physical properties, and also the question of allergy or toxicity to methylmethacrylate must be considered. The purpose of this study was to compare the degree of polymerization according to curing method and curing time. Five groups were desinged ; Group 1 was polymerizied at room temperature($28^{\circ}C$) ; Group 2 in $28^{\circ}C$ water ; Group 3 in $28^{\circ}C$ water under 30psi pressure ; Group 4 in $43^{\circ}C$ water ; Group 5 in $43^{\circ}C$ water under 30psi pressure for 10 minutes, 1 hour 12 hours, 1 day and 3 days. The degree of polymerization was measured by means of Fourier Transform Infrared spectroscopy. The results were as follows: 1. The degree of polymerization increased constantly in accordance with curing time in all groups and after curing for 10 minutes, Group 1 showed significantly higher degree of polymerization after 12 hours and Group 2, Group 3, Group 4, Group 5 after 1 hour(p<0.05). 2. The degree of polymerization decreased in the order of Group 5, Group 4, Group 3, Group 2, Group 1 except when the curing time was 1 hour and 12 hours(p<0.05). 3. The degree of polymerization of Group 4, Group 5 cured at $43^{\circ}C$ showed significantly higher degree of polymerization than Group 2, Group 3 at $28^{\circ}C$ except when the curing time was 1 day(p<0.05). 4. Among Group 2, Group 3 and Group 4, Group 5, the pressure had no effect on polymerization except when the curing time was 12 hours(p<0.05). 5. Between Group 1 and Group 2, the method of storage had no effect on polymerization except when the curing time was 1 hour(p<0.05).

• The korean journal of orthodontics
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• v.39 no.1
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• pp.36-42
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• 2009

Objective: The purposes of this study were to provide an epidemiologic data base related to the orthodontic treatment need and to know the changing trends about treatment modality of private orthodontic clinics. Methods: Distribution, trends and orthodontic treatment plan of malocclusion patients were investigated in 1,620 consecutive patients who had been visited and examined in 4 private orthodontic clinics located in Seoul from 2003-2006. Results: Percentage of male and female patients was 26.9% and 73.1% respectively Age distribution had shown that percentage of the patients above 13 years was 78.9%, and above 19 years was 59.0%. Average age of whole patients was 20.5 years. With regard to Angle classification, each percentage of Class I, Class II division 1, Class II division 2 and Class III malocclusion was 38.9%, 34.8%, 2.3% and 24.0%. The percentage of extraction cases(00.9%) outnumbered nonextraction cases(39.1%) and 46% of extraction cases were upper and lower 1st premolar extraction cases. Patients who had chose treatment with fixed appliance and orthognathic surgery was 10.2%. Conclusions: Because the high percentage of adult, Class II malocclusion and orthognathic surgery cases in patients of private orthodontic clinics were shown in this study, orthodontic education program and national health policy in Korea need reformation.

• Journal of the korean academy of Pediatric Dentistry
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• v.28 no.2
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• pp.281-286
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• 2001

The treatment method of impacted tooth is various from simple observation to surgical exposure and orthodontic methods, autotransplantation is concerned to severe malposed impacted tooth. Autotransplantation is the transplantation of embedded, impacted, of unerupted tooth, into extraction socket of surgically prepared in the same individual. Autotransplantation of tooth with $\frac{1}{2}{\sim}\frac{3}{4}$ root development provides a good chance of easily extracted, a little complication, pulp survival, and complete root formation. Transplantation of uncompleted root apex tooth is aim to pulpal healing, not endodontic treatment. The case which were treated with autotransplantation is reported, and induced normal physiologic eruption and good dental alignment.

• The korean journal of orthodontics
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• v.35 no.4 s.111
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• pp.312-319
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• 2005

Streptococcus mutans and Streptococcus sobrinus are major etiological agents in enamel demineralization around orthodontic appliances. This study was designed to examine the prevalence of these streptococci on orthodontic brackets in vivo using polymerase chain reaction. Four incisor brackets in the upper and lower arches were removed and collected from 80 patients at the time of debonding. The genomic DMA of adhered bacteria was extracted and each dextranase gene of S. mutans and S. sobrinus was amplified using the specific oligonucleotide primers. The results showed that the maxillary incisor brackets were colonized by both cariogenic streptococci to a somewhat higher degree than that taken from the mandible. The prevalence of S. mutans was $50.0\%$ on the maxillary incisor brackets and $33.8\%$ on the mandibular incisor brackets, and that of S. sobrinus was $17.5\%$ and $15.0\%$, respectively. Both species were detected on the maxillary incisor brackets of 7 patients $(8.8\%)$ and the mandibular incisor brackets of 5 patients $(6.3\%)$. These results suggest that cariogenic streptococci can adhere to the incisor brackets and may be resident species on the incisor brackets.

• Proceedings of the Korea Inteligent Information System Society Conference
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• 2000.04a
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• pp.435-442
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• 2000

만성질병, 식습관, 영양등 스트레스에 시달리는 현대인의 건강 상태를 파악하는 일은 매우 중요하며 또한 필요하다. 그러나 식이 섭취 평가는 많은 분야의 자료와 지식을 필요로 하기 때문에 손쉽게 일반인이 신뢰성 있는 평가는 얻기는 쉽지 않다. 본 연구는 식품, 영양, 조리, 만성질병, 식습관 등의 여러 전문 분야의 자료와 지식을 기반으로 한 웹 상에서의 영양 평가 시스템으로 '건강 관리를 위한 사이버 식생활 자가 진단 시스템(Cyber Food Self Diagnosis Program, 이하 Cyber-FSDP)'의 설계 및 구축에 관한 것이다. 바탕으로 한다. 초고속 통신망을 이용하여 사람들의 건강문제와 관련된 식생활 정보를 수집하고, 개인별 식생활을 사용자와 상호작용하게 온라인으로 평가·진단하여 이를 개선하고 궁극적으로는 만성질병 위험도를 감소시키고 건강을 증진시킬 수 있는 영양 및 만성 질병 평가 전문가 시스템을 구축한 사례에 대한 Web 응용 프로그램 개발을 소개하며, 개발환경으로는 서버를 엔터프라이즈 3000 Solaris 2.5.1을 사용했으며, DBMS는 IUS (Illustra Universal Server)를 사용하였고, APB(App Page Builder), JabaScript, HTML 등의 언어로 구현되었다.

• Journal of dental hygiene science
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• v.15 no.3
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• pp.259-264
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• 2015

For this experiment, specimen was manufactured by injecting polymer and monomer into silicon mold with volume ratio of 2.5:1 based on ISO 20795-2 so that average thickness, width and length of specimen would be maintained as 3.3 mm, 10.0 mm and 65.0 mm, respectively depending on spray on technique. Specimen was divided into 3 groups ($25^{\circ}C$, $40^{\circ}C$, $70^{\circ}C$) depending on polymerization temperature and 10 specimen was manufactured for each group and it was polymerized in water tank of ${\pm}1^{\circ}C$ under the setting condition of polymerization time of 15 minutes and pressure of 3 bar. After keeping specimen in distilled water of $37^{\circ}C$ for over 48 hours before experiment, flexural strength (FS) and elasticity modulus (EM) of specimen being tested by using Intron (3344; Instron; Instron). SPSS ver. 16.0 was used for analysis and post-hoc test of Scheffe was performed after using one-way ANOVA. When comparing mean value of FS of resin for orthodontics, it was represented in the range of 71.500 MPa for $25^{\circ}C$ group, 74.920 MPa for $40^{\circ}C$ group and 76.880 MPa for $70^{\circ}C$ group and difference was shown in the order of $25^{\circ}C$ group <$40^{\circ}C$ group <$70^{\circ}C$ group but such difference was not significant statistically (p=0.052). Result of EM mean value of resin for orthodontics was more polymerization temperature was high, the more was significant difference represented in the order of $25^{\circ}C$ group <$40^{\circ}C$ group <$70^{\circ}C$ group (p<0.039).