• 한국재료학회:학술대회논문집
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• 한국재료학회 2010년도 춘계학술발표대회
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• pp.40.2-40.2
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• 2010

In this study, oxidized alginate/gelatin/biphase calcium phosphate (BCP)- based hydrogel composites were fabricated. Alginate sodium was oxidized by periodate. The oxidized product was confirmed by using $^1H$ and $^{13}C$ NMR spectra. The number average molecular weight ($M_n$), the average molecular weight ($M_w$) of the oxidized alginate were determined by Gel Permeation Chromatography (GPC). The hydrogel was formed from the oxidized alginate and gelatin solution via Schift-base reaction. The hydrogel showed a highly porosity by a Scanning Electron Microscope (SEM) and Mercury Intrusion Porosimetry (MIP). Crosslinked density of the gel matrix were assessd by trinitrobenzene sulfonic acid (TNBS) assay that shows a high effect on swelling ratio. Increment of the crosslinked desity resulted in enhancing compressive strength of the hydrogel composite. The cytotoxity of hydrogel was assessed with osteoblast MG-63. The hydrogel composites show a high compatibility. The obtained results showed a potential application for bone regeneration in future.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제26권1호
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• pp.73-79
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• 2000

A material of 48 patients with 60 avulsed and replanted permanent teeth were followed retrospectively in the period of 1996. 1 to 1998. 12 (mean observation period=1year 7months). The age of the patients at the time of replantation ranged from 9 to 63 years (mean=24 years). Clinical records of patients were reviewed to obtain valid data concerning the extent of injury and treatment provided. Pulpal and periodontal healing states were examined with periapical x-rays and clinical examination procedures (i.e. percussion test and mobility test) at their recall visit. Root ankylosis was found in fifty-two teeth(87%) and root resorption in twenty-four(40%). Only two of the replanted teeth(3%) showed partial regeneration of the periodontal ligament. Six teeth(10%) resulted in tooth loss, but the remaining fifty-four were clinically well functioning. Most of teeth have mild marginal bone loss accompanied by gingival retraction without pathological periodontal pockets. The incidence of root resorption was much higher in younger age group. However, it was not affected by the interval between avulsion and replantation, the condition of supporting tissues, the degree of root formation and the type of splinting, indicating that multiple factors involved in determining the prognosis of replanted teeth. Based on these findings, avulsed teeth in unfavorable conditions (i.e. long extra-alveolar periods, etc.) should be preserved if possible.

• 대한구순구개열학회지
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• 제15권2호
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• pp.89-96
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• 2012

Le Fort 1 osteotomy or maxillary advancement with distraction osteogenesis (DO) is main treatment strategy for cleft palate patients with maxillary hypoplasia. Maxillary DO allows greater maxillary advancement within physiological limit than Le Fort 1 osteotomy. Moreover, it is better for velopharyngeal function. However, there is a greater tendency for an increase in nasal sound when maxilla is advanced excessively. Therefore, the advancement of anterior maxillary segment using DO has been utilized. It offers advantages such as an increase in the length of the palate, a prevention of the change in palatopharyngeal depth, and a preservation of the velopharyngeal function. Moreover, it will obliterate the necessity of bone graft, and it prevents the occurrence of oronasal or oroantral fistula. Finally, it stimulates the regeneration of the soft and hard tissue of alveolus, and subsequently makes possible to place implant.

• 대한소아치과학회지
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• 제24권4호
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• pp.727-733
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• 1997

Autotransplantation is a procedure which transplants teeth from the original position to other positions in the same individual. It is classified surgical reposition by intraalveolar autotransplantation and transalveolar autotransplantation. The prognosis for successful autotransplantation is dependent on a number of factors such as root development, surgical technique, patient's age, endodontic treatment, time and type of splinting, preservation of periodontal ligament and storage medium. The most important factor is preservation of periodontal ligament. The cause of the failure of transplantation include damage of the transplant during removal from deep palatal malposition, poor regeneration of the bone around the transplant and chronic periodontal infection. In case I, Impacted maxillary canine for which surgical exposure and orthodontic treatment was impossisle was transplanted. After 2 weeks, It showed periapical radiolucency and external root resorption. So, endodontic treatment was done. One year later, permanent filling was done with gutta percha. In case II, Transpositioned maxillary central incisor was transplanted after extraction of impacted mesiodens. Pulp vitality was maintained during 5 months without other clinical symptons.

• Journal of Periodontal and Implant Science
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• 제38권3호
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• pp.551-556
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• 2008

Purpose: Cemental tear is an uncommon form of root fracture that can lead to rapid localized attachment loss. When it is exposed in the periodontal pocket, it should be removed to prevent accumulation of dental plaque and calculus. Material and Methods: 2 patients were diagnosed as a cemental tear and they were treated with conventional flap operation and subgingival curettage. Additional treatments such as bone graft or guided tissue regeneration were not performed. Result: Symptoms subsided after the treatment. Periodontal pocket has been reduced but no gain of clinical attachment was observed. Remnant of cemental fragment remained after curettage. However, periodontal pocket was stably maintained and there was no recurrence. Conclusion: Periodontal attachment loss associated with cemental tear can be successfully treated with conventional periodontal surgical and nonsurgical procedures.

• Journal of Dental Anesthesia and Pain Medicine
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• 제17권4호
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• pp.289-295
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• 2017

Background: This study is aimed to evaluate the level of fear and to reduce the overall fear, thereby enabling patients to receive treatment via timely visits. Methods: In a survey conducted by 460 South Korean middle school students, we used 453 data that faithfully responded to the survey. Multiple regression analysis was conducted to investigate the factors influencing subjective oral health and dental fear. The significance level used for statistical significance was ${\alpha}=0.05$. Results: The level of fear was higher for upper grade, female students. The factors affecting dental fear were higher for gingival bleeding and dental pain. Regarding factors for dental fear affecting subjective oral health, lower fear of puncture needle and tooth removal tool resulted in higher subjective oral health. Conclusions: The study found that adolescents had higher fear of dental care when they had gingival bleeding and tooth pain. Gingival bleeding is a symptom of early gingival disease and dental pain is likely due to advanced dental caries. These results suggested that it is necessary to have a program to reduce dental fear and anxiety as well as a program to prevent dental diseases through regular periodic screening and education.

• International Journal of Industrial Entomology and Biomaterials
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• 제39권1호
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• pp.9-13
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• 2019

In this study, 4 different types of GBR membrane were undergone for bio-degradability test; Silk mat from silkworm cocoon (TDI), silk mat from flatwise-spun (FS), collagen membrane (OssGuide), and dPTFE membrane (Cytoplast). Each material was segmented in 10.00 mm length and 0.3 mm thickness. The samples were put into the normal saline at $37^{\circ}C$ for 2 weeks. After that, yield strength and tensile strain were measured and compared them with those of before treatment. The morphology of the membranes was observed by SEM. Tensile strain of FS was significantly increased at 2 weeks' normal saline treatment (P=0.018). When compared to OssGuide, TDI and FS showed significantly higher tensile strain at 2 weeks' normal saline treatment (P<0.05). In the SEM images, there were no significant changes in Cytoplast, TDI, and FS after 2 weeks' treatment. However, OssGuide showed damaged surface after 2 weeks' treatment. In conclusion, both TDI and FS did not have any evidence of biodegradability at 2 weeks' observation in normal saline treatment. However, OssGuide showed more than 20 % decrease in yield strength and tensile strain.

• 치위생과학회지
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• 제23권1호
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• pp.60-67
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• 2023

Background: In our study, a silver diamine fluoride (SDF) compound for the treatment of dental caries was synthesized to characterize its remineralization activity upon direct application to deciduous teeth. This study aimed to use microscopic computed tomography (microCT) and nanoindentation to evaluate whether SDF composite application could effectively arrest dental caries in five exfoliated primary molars. Methods: Carious teeth were extracted and visually examined using quantitative photofluorescence devices (Qraycam and QraypenTM). After performing microCT, the SDF composite was applied to the teeth according to the manufacturer's instructions. The researchers exchanged and precipitated the irritant saliva once daily for 1 week. The teeth were sectioned longitudinally through the centers of the mesial and distal surfaces, embedded, polished, and measured using nanoindentation. Thereafter, microCT was repeated. Statistical analyses were performed using GraphPad Prism software. Results: Following SDF composite application, a remineralized layer was observed on microCT images, and the hardness increased when measured using nanoindentation. We found that demineralized enamel presented with an increased number of irregular crystals in the deep carious lesion group compared with those in the shallow carious lesion group, resulting in a rougher surface. Conclusion: The SDF composite may be used for remineralization of early caries and cessation of advanced caries in primary molars.

• 치위생과학회지
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• 제13권2호
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• pp.158-164
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• 2013

임플란트 식립 시 가장 빈번하게 맞게 되는 문제점으로 임플란트 식립 부위에서의 불충분한 골량과 해부학적 구조에 의한 접근성의 문제를 들 수 있다. 일반적으로 성장 인자들은 치유 과정이나 조직 형성에 있어서 가장 기본적인 필수 요소로 인정되고 있다. 이러한 이유로 골 이식 재료의 효과를 증진시키기 위한 성장 인자들이 최근에 주목을 받고 있다. 혈소판 내 granules에는 높은 농도의 다양한 성장 인자들이 포함되어 있다. 특히, platelet-rich fibrin (PRF)는 2세대 혈소판 농축 인자로 항응고제가 들어있지 않은 상태로 얻을 수가 있고, 혈소판과 많은 성장 인자들이 풍부한 섬유소 막을 포함하고 있다. 이번 연구의 목적은 in vitro 상에서 골아 세포에 대한 PRF의 영향을 알아보고자 하였다. 특히 치유와 재생에 연관된 주요 기능으로써 증식과 분화에 대한 영향을 조사하고자 하였다. 이를 위해서, PRF 내에서 방출되는 성장 인자(platelet-derived growth factor subunit B와 transforming growth factor-${\beta}1$)의 농도, 세포의 생존능력, alkaline phosphatase (ALP) activity, type 1 collagen 합성, 골아 세포의 분화 지표로써 ALP와 Runx2의 발현 정도와 골 기질 단백질로써 type 1 collagen의 발현 정도에 대해서 조사하였다. 이 실험을 통하여 PRF는 치유 시 필요한 타당한 기간 동안에 충분히 자가 성장 인자의 방출을 유지하고 있음을 알 수 있었고, 골아 세포의 증식과 분화에 대해서 긍정적인 효과가 있음을 보여 주였다. 제한적인 실험이지만, 골재생을 위한 PRF의 사용은 골 치유와 골 개조에 있어서 증진 효과를 가져다줄 수 있는 촉망되는 방법 중 하나가 될 수 있을 것이다.

• 폴리머
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• 제36권6호
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• pp.789-794
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• 2012

생체적합성 및 생분해성의 장점을 지닌 PLGA는 우수한 기계적 성질과 분해속도를 조절할 수 있는 장점을 가지고 있지만 소수성으로 인해 세포의 초기부착률이 낮고, 지지체 내부에 영양액의 공급이 원활하지 않다. 본 연구에서는 이러한 단점을 보완하고자 탈미네랄화된 골분(DBP, demineralized bone particle) 젤을 PLGA 지지체에 함침시켰다. 다양한 형태의 지지체 압축강도를 측정한 결과 PLGA/DBP 지지체가 연골과 비슷한 강도를 가지고 있었으며, 이를 바탕으로 DBP젤을 함침시킨 PLGA/DBP젤 지지체를 제작하였다. 연골세포를 파종하여 in vivo 실험을 진행하였고 조직화 정도를 확인하기 위해 H&E, Safranin-O, Alcian blue, Collagen type I 및 Collagen type II 염색을 실시하였다. 그 결과 DBP를 함침시킨 PLGA 지지체에서 GAG, Collagen type I 및 Collagen type II의 높은 발현과 조직화를 보여 연골조직으로 대체할 수 있는 가능성을 확인하였다.