• 대한치과기공학회지
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• 제22권1호
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• pp.145-152
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• 2000

In order to select an effective antibiotic substance against oral resident bacteria, we were isolated from soil and texonomically analyzed. Seven hundred and eighteen strains were isolated on humic acid- vitamin agar(HV agar) and 220 strains were on methanol medium from three each paddy forest, field and riverside soil samples. So, during the screening of antibiotics from soil, we isolated microorganisms showing powerful antagonistic activity against oral resident bacteria. Microorganism was tested against 25 strains of bacteria, yeast and fungi. Among them, No. 248 strain exhibited the most strongly growth inhibition. So, the taxonomical analysis the isolated strain was found to be unknown Actinomyces sp. and was named No 248. A production of the antibiotics from No. 248 begins at the early exponential phase developed at the 72th hour under the optinum conditions. The property of No. 248 antimicrobial compound was very stable under acid(pH 3.0) and alkali(pH 10.0) treatment, but it was instable in heat treatment at $120^{\circ}C$. For the improvement of antibiotic activity, two mutants were isolated from strain No. 248 by the treatment of mutagenic agents, NTG and hydroxylamine. As a result, the mutant strains excreted the potent antibiotics to inhibit the growth of Candida albicans.

• 구강회복응용과학지
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• 제25권2호
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• pp.191-200
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• 2009

줄기세포는 미분화 상태의 세포로 지속적인 자가 분열능과 특정 세포로 분화 할 수 있는 분화능을 지니고 있으며 이러한 특성으로 말미암아 난치병의 새로운 장을 열 것이라는 기대감을 얻고 있다. 즉, 세포이식 후 특정 세포로 분화 유도를 시켜 기존의 치료 방법으로는 치료가 되지 않았던 많은 의학적 난제들을 풀 수 있는 열쇠인 것이다. 치아는 평생에 걸쳐 발거되는 조직으로 치아줄기세포는 얻기가 비교적 쉬워서 다른 성체줄기세포들보다 더 높이 평가되고 있다. 과잉치는 전 세계 다양한 인종에서 발견되는 중요한 임상적 질환이다. 과잉치의 유병율은 관련 연구 보고서마다 다양하나 소아치과 의사들의 경우 임상에서 자주 과잉치를 발거하고 있다. 그러나, 현재까지 진행된 줄기세포 관련 연구들을 살펴보면 과잉치의 줄기세포에 관한 보고는 없으며, 이는 줄기세포로 이용 가능한 중요한 자원을 파기하고 있는 것은 아닌지 의문이 생긴다. 그러므로 본 연구는 과잉치에 포함된 세포가 줄기세포의 특징을 가지고 있는지를 밝혀내기 위해 진행되었다.

• Journal of Dental Anesthesia and Pain Medicine
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• 제22권1호
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• pp.39-47
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• 2022

Background: This was a randomized controlled clinical trial that aimed to evaluate the anesthetic efficacy of 2% lidocaine combined with different concentrations of epinephrine (plain, 1:200,000 and 1:80,000) during endodontic treatment of maxillary molars with symptomatic irreversible pulpitis. Methods: The trial included 144 adult patients who were randomly allocated to three treatment groups. All patients received buccal-plus-palatal infiltration. After 10 min, pulp sensibility testing was performed using an electric pulp test (EPT). If a tooth responded positively, anesthesia was considered to have failed. In the case of a negative EPT response, endodontic access was initiated under rubber dam isolation. The success of anesthesia was defined as having a pain score less than 55 on the Heft Parker visual analog scale (HP VAS), which was categorized as 'no pain' or 'faint/weak/mild' pain on the HP VAS. Baseline pre-injection and post-injection maximum heart rates were recorded. The Pearson chi-square test was used to analyze the anesthetic success rates at 5% significance. Results: Plain 2% lidocaine and 2% lidocaine with 1:200,000 epinephrine and 1:80,000 epinephrine had anesthetic success rates of 18.75%, 72.9%, and 82.3%, respectively. Statistical analysis indicated significant differences between the groups (P < 0.001, 𝛘² = 47.5, df = 2). The maximum heart rate increase was seen with 2% lidocaine solution with epinephrine. Conclusion: Adding epinephrine to 2% lidocaine significantly improves its anesthetic success rates during the root canal treatment of maxillary molars with symptomatic irreversible pulpitis.

• 대한소아치과학회지
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• 제30권3호
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• pp.415-422
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• 2003

치면열구전색제의 예방효과는 전색제의 유지와 매우 밀접한 상관관계가 있으며 시술시의 환경과 시술 방법, 개개 환자의 구강 위생이 유지에 영향을 미치는 것으로 알려져 있다. 현재 우리나라에서는 대규모로 '치아홈메우기 사업'이 진행 중에 있지만 시술 여건이나 시술자에 따라 여러 가지 방법의 방습법과 치면 세마가 행해지고 있는 실정이다. 본 연구의 목적은 치면열구전색제의 시술 시 소아치과의사, 일반치과의사, 치과위생사 등 시술자에 따른 유지율 차이와 러버댐과 코튼롤(cotton roll) 방습법 등 격리 방법에 따른 유지율의 차이를 알아보고 실패가 일어나는 치아의 특정 부위를 알아보기 위한 것이다. 6세-11세인 119명의 아동(남자 64명, 여자 55명)에서 상하악 제1대구치에 시술된 279개의 치면열구전색제를 대상으로 1년 후의 유지율을 조사하였다. 이 아동들은 평균 연령이 $8.59{\pm}0.772$세였으며 각각 러버댐을 사용한 소아치과의사가 시술한 1군, 러버댐을 사용한 일반치과의사가 시술한 2군, 코튼롤(cotton roll)을 사용한 치과위생사가 시술한 3군으로 나누었다. 1년 후의 치면열구전색제의 유지율을 조사하여 다음과 같은 결론을 얻었다. 1. 1년 후의 치면열구전색제 유지율은 러버댐을 사용한 소아치과의사가 시술한 1군이 90.8%, 러버댐을 사용한 일반치과 의사가 시술한 2군은 85.0%, 코튼롤을 사용한 치과위생사가 시술한 3군은 64.7%였으며 1군과 2군간에는 통계적인 유의차가 없었으나(P>0.05) 1,2군과 3군 간에는 통계적인 유의차가 있었다(P<0.05). 2. 상악과 하악의 유지율 비교에서 1군과 2군은 차이가 없었으나(P>0.05) 3군은 차이가 있었다(P<0.05). 3. 실패부위 분석에서 교합면의 실패는 58.3%, 협/설면구는 41.7%를 차지하였다.

• Journal of Dental Anesthesia and Pain Medicine
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• 제21권3호
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• pp.237-244
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• 2021

Background: This study aimed to analyze Twitter users' emotional tendencies regarding oral surgery procedures before and after the coronavirus disease 2019 (COVID-19) pandemic worldwide. Methods: Tweets posted in English before and after the COVID-19 pandemic were included in the study. Popular tweets in 2019 were searched using the keywords "tooth removal", "tooth extraction", "dental pain", "wisdom tooth", "wisdom teeth", "oral surgery", "oral surgeon", and "OMFS". In 2020, another search was conducted by adding the words "COVID" and "corona" to the abovementioned keywords. Emotions underlying the tweets were analyzed using CrystalFeel - Multidimensional Emotion Analysis. In this analysis, we focused on four emotions: fear, anger, sadness, and joy. Results: A total of 1240 tweets, which were posted before and after the COVID-19 pandemic, were analyzed. There was a statistically significant difference between the emotions' distribution before and after the pandemic (p < 0.001). While the sense of joy decreased after the pandemic, anger and fear increased. There was a statistically significant difference between the emotional valence distributions before and after the pandemic (p < 0.001). While a negative emotion intensity was noted in 52.9% of the messages before the pandemic, it was observed in 74.3% of the messages after the pandemic. A positive emotional intensity was observed in 29.8% of the messages before the pandemic, but was seen in 10.7% of the messages after the pandemic. Conclusion: Infectious diseases, such as COVID-19, may lead to mental, emotional, and behavioral changes in people. Unpredictability, uncertainty, disease severity, misinformation, and social isolation may further increase dental anxiety and fear among people.

• Restorative Dentistry and Endodontics
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• 제46권2호
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• pp.26.1-26.15
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• 2021

Objectives: The aim of the present systematic review was to investigate the cryopreservation process of dental pulp mesenchymal stromal cells and whether cryopreservation is effective in promoting cell viability and recovery. Materials and Methods: This systematic review was developed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement and the research question was determined using the population, exposure, comparison, and outcomes strategy. Electronic searches were conducted in the PubMed, Cochrane Library, Science Direct, LILACS, and SciELO databases and in the gray literature (dissertations and thesis databases and Google Scholar) for relevant articles published up to March 2019. Clinical trial studies performed with dental pulp of human permanent or primary teeth, containing concrete information regarding the cryopreservation stages, and with cryopreservation performed for a period of at least 1 week were included in this study. Results: The search strategy resulted in the retrieval of 185 publications. After the application of the eligibility criteria, 21 articles were selected for a qualitative analysis. Conclusions: The cryopreservation process must be carried out in 6 stages: tooth disinfection, pulp extraction, cell isolation, cell proliferation, cryopreservation, and thawing. In addition, it can be inferred that the use of dimethyl sulfoxide, programmable freezing, and storage in liquid nitrogen are associated with a high rate of cell viability after thawing and a high rate of cell proliferation in both primary and permanent teeth.

• 치위생과학회지
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• 제8권3호
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• pp.183-187
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• 2008

본 연구는 치과 진료실에서 발생할 수 있는 S. aureus균의 분포를 일부 치위생과 임상실습실을 통해 알아보고 교차감염 가능성을 제시하기 위해 시행되었다. 대상은 사람과 환경을 기준으로 하였으며 사람은 실습학생과 실습환자, 환경은 임상실습실과 실습강의실, 소독실에서 시행되었으며 시간은 진료 전과 진료 중, 진료 후를 조사 평가 하였다. 1. 전체 균주 중 S. aureus는 환자의 구강에서 55%, 비강에서 35%, 구순에서 10%가 체취 되었으며 술자인 학생에게서는 구강이 50%, 비강이 40%, 구순이 15%가 체취 되어 사람에게서는 구강에서 가장 많은 S. aureus가 나타났으며 환자와 술자 간에 유의한 차이는 없었다. 2. 임상 실습실의 시간과 장소에 따른 S. aureus의 분포는 전체적으로 진료 도중에 가장 많이 발견 되었으며 특히 라이트 손잡이와 머리 받침대, 타구에서 큰 차이를 보였으며(p < 0.001), 유니트 체어의 버튼과 손잡이 부분과 3-way syringe, 트레이 테이블, 문 손잡이 부분에서도 유의하게 나타났다(p < 0.05). 3. 실습 강의실은 수업 중 책상에서만 S. aureus의 분포가 유의하게 나타났지만 전반적으로 마네킨과 의자, 창틀에서도 사람이 활동하는 시간에 S. aureus의 분포가 많은 것으로 나타났다. 4. 소독실의 경우 소독실로 들어가는 손잡이에서만 진료 도중 S. aureus의 분포가 유의하게 나타났고(p < 0.001) 소독기와 기구 트레이, 약제 트레이에서는 진료 도중에 S. aureus가 출현하지 않았다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제36권3호
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• pp.186-196
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• 2010

Introduction: The first aim of this study was to isolate the dental tissue-derived stem cells from the dental follicle (DF), dental pulp (DP), and root apical papilla (RAP) of the extracted wisdom teeth. Second was to evaluate their characterization with the expressions of transcription factors and cell surface markers. Finally, their ability of the in vitro multi-lineage differentiations into osteogenic and adipogenic cells were compared, respectively. Materials and Methods: Dental tissues, including dental follicle, dental pulp, and root apical papilla, were separated in the extracted wisdom teeth. These three dental tissues were cultured in Dulbecco’s modified Eagle’s medium (DMEM) with supplements, respectively. After passage 3, the homogeneous shaped dental tissue-derived cells were analyzed the expression of transcription factors (Oct-4, Nanog and Sox-2) and cell surface markers (CD44, CD90 and CD105) with reverse transcription polymerase chain reaction (RT-PCR) and fluorescence-activated cell sorting (FACS) analysis. In order to evaluate in vitro multi-lineage differentiations, the culture media were changed to the osteogenic and adipogenic induction mediums when the dental tissue-derived cells reached to passage 3. The characteristics of these three dental tissue-derived cells were compared with immunohistochemistry. Results: During primary culture, heterogenous and colony formatted dental tissue-derived cells were observed in the culture plates. After passage 2 or 3, homogenous spindle-like cells were observed in all culture plates. Transcription factors and mesenchymal stem cell markers were positively observed in all three types of dental tissue-derived cells. However, the quantity of expressed transcription factors was most large in RAP-derived cells. In all three types of dental tissue-derived cells, osteogenic and adipogenic differentiations were observed after treatment of specific induction media. In vitro adipogenic differentiation was similar among these three types of cells. In vitro osteogenic differentiation was most strongly and frequently observed in the RAP-derived cells, whereas rarely osteogenic differentiation was observed in the DP-derived cells. Conclusion: These findings suggest that three types of human dental tissue-derived cells from extracted wisdom teeth were multipotent mesenchymal stem cells, have the properties of multi-lineage differentiations. Especially, stem cells from root apical papilla (SCAP) have much advantage in osteogenic differentiation, whereas dental follicle cells (DFCs) have a characteristic of easy adipogenic differentiation.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제23권1호
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• pp.82-86
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• 2001

저자 등은 하악 우측 제3대구치 발거 후 발치와를 통해 하악골에 이환되어 발생한 경안부 방선균증에서 병소부의 적출술과 소파술을 시행하고, 항생제 요법 및 개방창 유지등의 방법을 통해 양호한 경과를 보였기에 문헌고찰과 함께 보고하는 바이다.

• Molecules and Cells
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• 제41권1호
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• pp.35-44
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• 2018

Mitochondria are responsible for supplying of most of the cell's energy via oxidative phosphorylation. However, mitochondria also can be deleterious for a cell because they are the primary source of reactive oxygen species, which are generated as a byproduct of respiration. Accumulation of mitochondrial and cellular oxidative damage leads to diverse pathologies. Thus, it is important to maintain a population of healthy and functional mitochondria for normal cellular metabolism. Eukaryotes have developed defense mechanisms to cope with aberrant mitochondria. Mitochondria autophagy (known as mitophagy) is thought to be one such process that selectively sequesters dysfunctional or excess mitochondria within double-membrane autophagosomes and carries them into lysosomes/vacuoles for degradation. The power of genetics and conservation of fundamental cellular processes among eukaryotes make yeast an excellent model for understanding the general mechanisms, regulation, and function of mitophagy. In budding yeast, a mitochondrial surface protein, Atg32, serves as a mitochondrial receptor for selective autophagy that interacts with Atg11, an adaptor protein for selective types of autophagy, and Atg8, a ubiquitin-like protein localized to the isolation membrane. Atg32 is regulated transcriptionally and post-translationally to control mitophagy. Moreover, because Atg32 is a mitophagy-specific protein, analysis of its deficient mutant enables investigation of the physiological roles of mitophagy. Here, we review recent progress in the understanding of the molecular mechanisms and functional importance of mitophagy in yeast at multiple levels.