• The Journal of Advanced Prosthodontics
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• 제7권6호
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• pp.431-436
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• 2015

PURPOSE. The aim of this study was to evaluate occlusal contacts generated by 3 different biogeneric design modes (individual (BI), copy (BC), reference (BR)) of CEREC software and to assess the designs subjectively. MATERIALS AND METHODS. Ten pairs of maxillary and mandibular casts were obtained from full dentate individuals. Gypsum cast contacts were quantified with articulating paper and digital impressions were taken. Then, all ceramic crown preparation was performed on the left first molar teeth and digital impressions of prepared teeth were made. BI, BC, and BR crowns were designed. Occlusal images of designs including occlusal contacts were superimposed on the gypsum cast images and corresponding contacts were determined. Three designs were evaluated by the students. RESULTS. The results of the study revealed that there was significant difference among the number of contacts of gypsum cast and digital models (P<.05). The comparison of the percentage of virtual contacts of three crown designs which were identical to the contacts of original gypsum cast revealed that BI and BR designs showed significantly higher percentages of identical contacts compared with BC design (P<.05). Subjective assessment revealed that students generally found BI designs and BR designs natural regarding naturalness of fissure morphology and cusp shape and cusp tip position. For general occlusal morphology, student groups generally found BI design "too strong" or "perfect", BC design "too weak", and BR design "perfect". CONCLUSION. On a prepared tooth, three different biogeneric design modes of a CAD/CAM software reveals different crown designs regarding occlusal contacts and morphology.

• 구강회복응용과학지
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• 제28권4호
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• pp.407-421
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• 2012

악악면 부위의 교정적 문제는 크게 골격적인 문제와 치성적 문제로 나룰 수 있다. 치성적 문제로 인해서 많은 교합의 부조화가 발생하는데 이중 치아의 결손 또는 치아의 맹출 실패는 기능적 문제뿐만이 아니라 심미적 문제도 같이 유발한다. 또한 추가적으로 발생하는 심리적인 문제도 환자를 내원하게 만드는 중요한 이유이다. 상악골에 다수의 치아가 맹출 하지 못하는 경우에는 교합적, 심미적 문제 뿐만 아니라 치조골의 유지 또한 어렵게 하는 문제가 발생한다. 따라서 다수치의 맹출에 문제가 있는 경우에는 보다 단계적 접근이 필요하다. 본 증례의 환자는 #13, 12, 11, 23, 43이 맹출하지 못하는 문제를 주소로 내원하였으며, 상악 치아들을 맹출하게 하기위한 외과적 노출술 및 단계별 교정적 정출을 통하여 완벽한 교합을 이룰 수 있었다. 또한 추가적인 치주 처치를 통하여 치아맹출시 발생한 치은 퇴축을 제거하였다. 우측 매복 하악 견치는 자연스러운 악궁 확장과 leeway space를 이용하여 특별한 외과적 처치 없이 성공적으로 이루어졌다.

• 구강회복응용과학지
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• 제32권4호
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• pp.307-313
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• 2016

심한 마모를 보이는 환자에서 자연치를 이용한 피개의치는 하나의 치료 방법이 될 수 있다. 자연치를 이용한 피개의치는 치조골의 보존, 감각수용기능의 유지를 가능하게 하며 강한 지지를 제공한다. 또한 지대치와 의치 지지조직에 가해지는 응력집중을 분산시키며, 의치에 의한 이차고정으로 장기간의 안정성을 제공해줄 수 있다는 장점이 있다. 본 증례는 심한 마모와 우식으로 인해 소수 건전치를 가지는 환자에서 자연치 피개의치를 이용하여 수복한 증례로 심미적, 기능적으로 만족스러운 결과를 얻었기에 보고하는 바이다.

• 대한치과보철학회지
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• 제34권3호
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• pp.501-532
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• 1996

This study investigated the effects of cantilever length, location and load condition on stress distribution developed in the implants, prostheses and supporting tissues. The osseointegrated prostheses with two 10mm Branemark implants at 2nd premolar and 1st molar sites with cantilever extensions at 1st premolar, 2nd and 3rd molar sites were constructed. Under 100N, 200N of vertical and $45^{\circ}$ oblique loads at the cantilever pontics, stress distribution patterns and displacement were analyzed with three dimensional finite element method. The results were as follows : 1. The stress was concentrated at the joint of the cantilever pontic and implant superstructure, the neck of implant and the ridge crest near the cantilever But there was little load transfer to the lower supporting tissues of implants. 2. The implant near the cantilever was displaced inferiorly while the implant far from the cantilever was displaced superiorly. In horizontal direction the implants were displaced to the direction where the loads were applied, except the apexes of the implants. 3. In case of anterior cantilever, the stress and displacement were higher than the prosthesis connected with natural tooth. 4. The stress developed in the posterior cantilevered type was higher than in the anterior cantilevered type. The greastest stress was concentrated at the ridge crest near the posterior cantilever. 5. The longer the cantilever, the more the stress was developed and was concentrated at the joint of the cantilever pontic and implant superstructure. 6. Under oblique load, the stress was concentrated at the necks of implants and the ridge crests, but decreased at the joint of the cantilever pontic and implant superstructure than under vertical load.

• Restorative Dentistry and Endodontics
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• 제45권3호
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• pp.31.1-31.20
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• 2020

Matrix metalloproteinases (MMPs) are enzymes that can degrade collagen in hybrid layer and reduce the longevity of adhesive restorations. As scientific understanding of the MMPs has advanced, useful strategies focusing on preventing these enzymes' actions by MMP inhibitors have quickly developed in many medical fields. However, in restorative dentistry, it is still not well established. This paper is an overview of the strategies to inhibit MMPs that can achieve a long-lasting material-tooth adhesion. Literature search was performed comprehensively using the electronic databases: PubMed, ScienceDirect and Scopus including articles from May 2007 to December 2019 and the main search terms were "matrix metalloproteinases", "collagen", and "dentin" and "hybrid layer". MMPs typical structure consists of several distinct domains. MMP inhibitors can be divided into 2 main groups: synthetic (synthetic-peptides, non-peptide molecules and compounds, tetracyclines, metallic ions, and others) and natural bioactive inhibitors mainly flavonoids. Selective inhibitors of MMPs promise to be the future for specific targeting of preventing dentin proteolysis. The knowledge about MMPs functionality should be considered to synthesize drugs capable to efficiently and selectively block MMPs chemical routes targeting their inactivation in order to overcome the current limitations of the therapeutic use of MMPs inhibitors, i.e., easy clinical application and long-lasting effect.

• Restorative Dentistry and Endodontics
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• 제36권2호
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• pp.114-118
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• 2011

연구목적: 본 연구는 치근단절제술과 역충전을 시행한 환자를 대상으로 치근단미세수술의 결과에 대한 환자의 인식과 만족도를 조사하는 것을 목적으로 하였다. 연구 재료 및 방법: 연세대학교 치과보존과에서 치근단 수술 후 최소 3개월 이후 정기검진을 위해 내원한 환자를 대상으로 설문조사를 시행하였다. 응답자의 나이/성별간 응답의 차이가 있는지는 contingency table을 이용해서 분석하였다 (p=0.05). 결과: 응답자의 60% 정도가 이전에 치근단 수술에 대해서 들어본 적이 없었으며 치근단 수술을 결정한 이유는 63.3%에서 자연치를 보존하기 위해서라고 응답하였다. 이후 비슷한 상황이 생긴다면 대부분의 환자가 다시 치근단수술을 선택할 것이라고 하였으며 수술의 만족도는 전반적으로 높은 편이었다. 결론: 치근단수술은 대부분의 환자에서 만족스러운 치료로 인식되고 있다.

• 대한치과보철학회지
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• 제59권4호
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• pp.469-477
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• 2021

상악 전치부 임플란트의 성공적인 수복을 위해서는 pink esthetics와 white esthetics가 모두 충족되어야 한다. Pink esthetics 부분의 경우 적절한 임시보철물의 역할이 중요하고, white esthetics 부분의 경우에는 최종 보철물의 색상과 형태가 중요하다. 다층 지르코니아는 기존의 단일구조 지르코니아에 비해 절단 부위의 투명도가 높기 때문에 추가적인 도재 축성 없이 자연스러운 보철물 제작이 가능하다. 따라서 본 증례에서는 상악 전치를 상실한 환자에서 적절한 임시보철물을 통해 기능과 심미성을 충분히 회복한 후 다층 지르코니아를 통해 white esthetics를 달성하였다.

• Asian-Australasian Journal of Animal Sciences
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• 제32권6호
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• pp.896-903
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• 2019

Objective: Qianbei-Pockmarked goats are affected by a disorder locally referred to as 'Ruanguzheng Disorder', which is characterized by emaciation, lameness, muscular relaxation, stiffness of the extremities, and abnormal curvatures of the long bones. Our objective was to determine the relationship between the disorder and phosphorus deficiency. Methods: Tissue samples were collected from affected and healthy animals, while soil and herbage samples were collected from affected and healthy pastures. Biochemical parameters were determined using an automatic biochemical analyzer (OLYMPUS AU 640, Olympus Optical Co., Tokyo, Japan). Mineral contents in soil, forage, and tissue were determined using a Perkin-Elmer AAS5000 atomic absorption spectrophotometer (Perkin-Elmer, Norwalk, CT, USA). Results: The results showed that phosphorus contents in herbages from affected pastures were markedly lower than those from healthy areas (p<0.01), and the ratio of calcium to phosphorus in the affected herbages was 12.93:1. The phosphorus contents of wool, blood, tooth, and bone from affected animals were also markedly lower than those from healthy animals (p<0.01). Serum phosphorus values in affected animals were much lower than those in healthy animals, while serum alkaline phosphatase values from affected animals were markedly higher than those from healthy animals (p<0.01). Inorganic phosphorus values from affected animals were approximately half of that in the control group. Supplementation of disodium hydrogen phosphate prevented and cured the disorder. Conclusion: This study demonstrates that Ruanguzheng disorder in Qianbei-Pockmarked goats is primarily caused by phosphorus deficiencies in herbage due to fenced pastures and natural habitat fragmentation.

• 한국콘텐츠학회논문지
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• 제20권12호
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• pp.454-459
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• 2020

구강질환의 주된 원인은 치면세균막 형성이며, 억제하는 방법의 하나로 화학제재로 된 구강세정제를 사용한다. 하지만 화학제재는 부작용이 발생할 염려가 있어 본 연구에서 천연물질인 대나무 추출물의 구강미생물에 대한 항균효과를 검증하고자 하였다. 대상자는 대구에 소재한 대학교 학생으로 대조군, 실험군 각 15명씩을 선정 후 대조군은 증류수 양치액, 실험군은 대나무 추출물의 사용 전, 후의 구강병원성 미생물의 변화를 비교하였다. 수집된 자료는 SPSS Windows ver. 20.0을 이용하여 분석하고, 통계적 유의수준은 p<0.05로 하였다. 그룹간의 양치액 사용 후 병원성 미생물의 변화차이를 알아보기 위해 Mann-Whitney test를 실시하였으며, 총 병원미생물수가 실험군은 -1.27±1.26, 대조군이 0.26±1.21로 높은 것으로 나타났고 이는 통계적으로 유의한 것으로 나타나 결과적으로 부작용이 적으면서 우수한 구강양치액의 개발에 기초자료를 제공할 것으로 기대된다.

• Natural Product Sciences
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• 제26권4호
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• pp.326-333
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• 2020

The aerial parts of Eclipta prostrata is used as a traditional medicine and vegetable. In traditional folk medicine, it is used for treatment of hemorrhages, hepatic, disease, renal injuries, hair loss, tooth mobility, and viper bites. In this study, ten compounds (1 - 10) were isolated from the aerial parts of E. prostrata. A reliable high performance liquid chromatography equipped with photometric diode array detector (HPLC-PDA) method was developed to simultaneously quantitate 10 marker compounds [chlorogenic acid (1), paratensein 7-O-��-ᴅ-glucoside (2), quercetin 7-O-��-ᴅ-glucoside (3), luteolin 7-O-��-ᴅ-glucoside (4), apigenin 7-O-��-ᴅ-glucoside (5), apigenin 4'-O-��-ᴅ-glucoside (6), apigenin (7), luteolin (8), wedelolactone (9), and paratensein (10)]. In addition, compounds 5 and 6 showed considerable inhibitory effects against protein-tyrosine phosphatase 1B (PTP1B) enzyme. Moreover, compounds 6 - 8, and 10 exhibited potent α-glucosidase inhibitory effects with IC50 values of 24.5 ± 1.9, 33.0 ± 0.5, 45.5 ± 0.1, and 23.8 ± 1.0 µM, respectively. All compounds (1 - 10) showed considerable acetylcholinesterase (AChE) inhibitory effects with IC50 ranging from 30.1 to 75.2 µM.