• Restorative Dentistry and Endodontics
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• 제16권2호
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• pp.155-164
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• 1991

The purpose of this study was to evaluate the effects of bleaching agent through the dentinal tubules of cervical area in the intracoronal bleaching of pulpless teeth on cutured fibroblast cells. Extracted human incisors were enlarged to # 40 K-file and obturated with gutta-perella and AH 26 sealer. The gutta-percha was removed to 2mm below the cementoenamel junction of the root The teeth were divided into 3 experimental and control groups. Experimental groups; Experimental group 1: Temporary inlay wax filld with 30% $H_2O_2$ in pulp cavity. Experimental group 2: Temporary inlay wax filld with 30% $H_2O_2$ in pulp cavity after placement of ZOE cement to cementoenamel junction. Experimental group 3: Temporary inlay wax filld with 30% $H_2O_2$ in pulp cavity after application of Copalite to cementoenamel junction. Control group: Temporary inlay wax filled without 30% $H_2O_2$ in pulp cavity under the same condition at each experimental group. Each tooth was immersed in well of multidish cultured fibroblast cell for 48 hours. The cellular multiplication and cell viability were calculated at the interval of 1, 3, 5. 7 hours and the morphological changes in well were observed and their photographs were taken with inverted microscope. The obtained results were as follows : CD The cellurar multiplicaton and cell viability decreased in all experimental groups at 1 hour after experiment and the morphology of fibroblast cell was changed from star shape to round (2) The cell viability was lowered to 34 % in experemental group 1, 44 % in experimental group 2, and 38 % in experemental group 3 at 3 hours after experiment (3) The cell multiplication was decreased to 54% in experemental group 1. 47% in experimental group 2, and 40% in experemental group 3 at 7 hours after experiment. (4) The decrease of cell number and morphological changes of fibroblast cell were remarkable in experimental group 1, group 3 and 2 in order. These results suggest that the fibroblast cells receive severe damage by 30% $H_2O_2$ solution leaked through the dentinal tubules and the dentinal tubules are able to be obturated better by ZOE cement than by Copalite.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제29권2호
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• pp.102-107
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• 2003

At orthodontic treatment, we have made every effort to get rigid anchorage which is not stirred when teeth move. As a result, the miniscrew that is rigid anchorage was invented recently, and now it is used widely. Concerning the advantage of miniscrew, it is reduced dependence of extraoral anchorage and it shortens treatment time for rapid tooth movement. In contrast, the defect of miniscrew is falling off it resulted from increasing of the mobility. So the purpose of this research is to be of help to prognose clinical use of miniscrew, which is inserted for intraoral anchorage, by investigating and comparing the failure rate of miniscrew for loading time. This study researches the failure rate of miniscrew for teeth movement at the orthodontic treatment. The failure rate of miniscrew in mid course, after inserting 147 miniscrews in 51 patients, is 13%(20/147). It showed no statistically significant differences as compared man with woman, maxilla with mandible, double-head with uni-head miniscrew, and drilling and non-drilling before inserting the miniscrew. In comparison below twenties with over twenties and the times that we give load to miniscrew, it produced that the failure rate of miniscrew is 9.7% higher in the case of below the twenties than over the twenties. Also, the failure rate of loading immediately is 10.8% higher than loading after 7 days. According to using driver for the insertion of miniscrew, the failure rate of miniscrew is higher in the case of using machined driver than in the case of using hand driver when the level of significance is 95%. According to the research, we can suppose that the failure rate has no concern with using miniscrew on man or woman, maxilla or mandible, the shape of head, and drilling or non-drilling before insertion of miniscrew. Therefore, we can choose eclectic miniscrew as demands. In addition, we must notify the patient, below twenties, to be possibility of high failure rate. And It is strongly recommended to give load after $1{\sim}2$ weeks for healing of the insertion area.

• 대한치과보철학회지
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• 제30권2호
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• pp.259-271
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• 1992

This study was designed to investigate the criteria of the perfect smile that was necessary to improve the esthetic problem in oral and maxillo-facial region and treating the anterior tooth region. The author took the facial straight photograph of 240 university students(male : 129, female : 111) in a resting and a smiling position, measured and analized the lip pattern and the relation between the lip and the teeth when they were smiling. Besides, 10 members of committee for appraisal (dentist : 5 persons, professor of the college of fine arts : 5 persons) estimated the smiling pattern. After that the author have compared and analyzed the obtained results. The results obtained were as follows : 1. In the shape of the upper lip, when the upper lip curved downward, it was 42.92% , straight was 45.00% and curved upward was 12.08%. The group in which the upper lip curved upward was the most esthetic. 2. In the relation between the upper lip and the teeth, high smile was 29.17%, average smile was 55.83% and low smile was 15.00%. The group of average smile was the most esthetic. 3. In the parallel relation between the lower lip and maxillary anterior incisal curvature, the group of paralled was 60.42%, the group of straight was 34.17% and the group of reverse was 5.41%. The group of parallel was the most esthetic. 4. In the relationship between maxillary anterior incisor and lower lip, the group of the maxillary anterior incisor were slightly covered by the lower lip was 10.42%, the group of the maxillary anterior teeth touched to the lower lip was 35.83%, and the no-touching was 53.75%. The group of the maxillary anterior teeth touched to the lower lip was the most esthetic. 5. In the teeth displayed in a smile, displayed to the canine was 0.84%, displayed to the first premolar was 19.17%, displayed to the second premolar was 57.92%, displayed to the first molar was 20.00% and displayed to the second molar was 2.08%. The group of displayed to the first molar was the most esthetic. 6. At smiles, the width of the mouth corner was 0.46 times of the full face width, 0.95 times of the interpupillary distance, and 1.23 times of the resting position. 7. At smiles, the lengh of the upper lip was 0.71 times and lower lip was 0.93 times of the length in the resting position.

• 대한소아치과학회지
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• 제30권1호
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• pp.80-91
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• 2003

치아우식증의 원인균인 S. mutans GS5와 S. sobrinus 6715에 대한 polyP의 효과를 관찰하여 보다 안전하고 효과적인 치아우식증 예방을 위한 임상적용의 가능성을 고찰하고자 첫째, 다양한 사슬길이의 polyP를 첨가한 후 흡광도를 측정하여 MIC를 결정하고, 둘째, 실험균주를 흡광도 $0.3{\sim}0.5$까지 증식시킨 후 MIC 농도의 polyP를 첨가하여 흡광도의 변화를 측정함으로써 균주증식 후 성장 억제효과를 관찰하였으며, 셋째, 생균수 측정으로 polyP의 항균효과를 평가하였고, 넷째, 핵산유리의 정도로 polyP의 킬레이션 작용여부를 관찰하였으며, 다섯째, polyP의 비수용성 글루칸 합성능력을 관찰하였으며, 여섯째, 투과전자현미경으로 세포막과 세포질 내의 구조적 변화를 관찰하였다. 이상의 연구를 통하여, polyP의 살균작용이 S. mutans와 S. sobrinus에 대한 성장을 억제시키는 효과가 있는 것으로 가늠된다. 이와 같은 성장 억제효과는 polyP의 킬레이션에 의한 것이라기보다는 균주 세포의 구조적, 형태적 변화가 주된 요인이었던 것으로 판단된다.

• 대한소아치과학회지
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• 제36권4호
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• pp.601-606
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• 2009

법랑질형성부전증은 치아 법랑질의 유전성 결함으로 임상적으로 형성부전형, 성숙부전형, 석회화부전형의 3가지로 나뉜다. 이 질환은 유치와 영구치에서 모두 발생할수 있다. 본 증례의 환자는 8세 8개월에 상악 영구 전치의 맹출지연 및 하악 전치부위 치석, 전치부 개방교합을 주소로 개인병원에서 의뢰되어 본과에 내원하였다. 본과에서 임상검사 결과, 상, 하악 전치부의 얇은 법랑질과 좁은 치아 폭경을 보였으며, 특히 하악 전치부는 전체적인 형태상 불량하고 거친 표면을 나타냈다. 또한 온도 자극에 민감한 반응을 나타냈다. 상, 하악 제 1 대 구치는 심한 법랑질 파절과 마모를 보였다. 방사선 검사에서 전반적인 법랑질형성부전증을 보였으며 맹출하지 않은 치아에서도 법랑질형성부전증을 볼 수 있었다. 이에 본 환아는 형성부전형 법랑질형성부전증으로 진단내렸으며, 경희대학교 소아치과와 보철과의 협진하에 치료를 시행하였으며 지속적인 관찰 중이다. 법랑질형성부전증 환자의 효율적인 저작능력, 심미성 회복, 지각과민증 해소를 위하여 구강 위생교육, 구치부 및 전치부의 수복이 필요하다. 성장이 완료될 때까지 지속적인 예방치료 및 치아 수복이 필요하며 성장 완료 후에는 여러 과의 협진적 치료가 필요하다.

• Journal of Periodontal and Implant Science
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• 제36권3호
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• pp.673-682
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• 2006

Recent study shows that implant design has a great impact on initial stability in bone. The ITI $TE^{(R)}$ implant, designed originally for immediate placement has a tapered/ cylindrical form which fits the anatomical shape of the natural alvelous or tooth root. The increased diameter at the collar region coupled with more threads lead to more bone contact and enhanced stability. The aim of this retrospective study is to evaluate the clinical use and the efficacy of recently introduced ITI TE implant with a new macro-design. The following results are compiled from 139 patients who received ITl TE implant surgery at the periodontal department. of Yonsei University Hospital between July 2002 and September 2005. 1. 139 patients received 173 ITl $TE^{(R)}$ implants in their maxilla and mandible (Mx 82, Mn 91). Posterior area accounted for 84% of the whole implant surgery, 2. In the distribution of bone quality, type III(41,0%) was the most, followed by type IV(41,0%) and type II (27.7%). As for the bone quantity, type B(43.9%) was the most, followed by type C(42.2%), type D(12.2%) and type A(1.7%). 3. 125 implants(83.9%) were treated by single crown, which accounted for the majority. 4, The total implant survival rate was 100% after a mean follow-up period of 21.2 months. This preliminary data with ITl $TE^{(R)}$ implant showed excellent survival rate although the majority of implants evaluated in this study were placed in the posterior region of the jaw and compromised sites.

• 구강회복응용과학지
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• 제30권4호
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• pp.265-277
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• 2014

목적: 고정식 교정장치에서 removable sliding jig (R-jig)와 temporary anchorage devices (TADs)를 이용하여 상악 구치의 원심 이동 시 힘의 크기와 와이어의 단면 크기에 따른 치아 이동과 치조골에 미치는 효과의 차이를 유한요소방법을 통하여 분석하고자 한다. 연구 재료 및 방법: 정상적인 치아 크기와 악궁 형태를 가진 상악 치아와 상악 치조골을 3차원 형상 모델링하고, 브라켓, 교정용 호선 및 R-jig를 포함한 유한요소 모델을 제작하였다. 골격성 고정원인 mini-implant를 제2소구치와 제1대구치 사이 협측으로 주호선 기준 8 mm 상방 위치시키고, mini-implant를 직접 고정원으로 사용하여 R-jig에 후방력을 부여하였다. 주호선을 $0.019{\times}0.025$ inch SS로 설정하고, R-jig의 와이어 단면 크기를 $0.019{\times}0.025$ inch SS, 후방력의 크기를 200 gm, 결찰을 하지 않는 조건을 기준 조건으로 설정하였다. 그리고 R-jig의 와이어 단면 크기, 후방력의 크기를 다르게 한 조건들을 설정하여 비교하였다. 결과: R-jig의 와이어 단면 크기가 증가함에 따라 후방력에 의한 R-jig의 변형이 적게 관찰되었지만, 제2대구치의 변위량은 아주 미미한 차이를 보였다. 제2대구치에 가해지는 후방력의 크기가 증가할수록 변위량도 같이 증가하였고, 원심경사 경향과 수직 변위량도 더 커졌다. 결론: R-jig는 임상적으로 큰 부작용 없이 치아의 원심이동을 가능하게 한다.

• Imaging Science in Dentistry
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• 제40권2호
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• pp.69-74
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• 2010

Purpose : The research was performed to predict the three dimensional relationship between the impacted mesiodens and the maxillary central incisors and the proximity with the anatomic structures by comparing their panoramic images with the CT images. Materials and Methods : Among the patients visiting Seoul National University Dental Hospital from April 2003 to July 2007, those with mesiodens were selected (154 mesiodens of 120 patients). The numbers, shapes, orientation and positional relationship of mesiodens with maxillary central incisors were investigated in the panoramic images. The proximity with the anatomical structures and complications were investigated in the CT images as well. Results : The sex ratio (M : F) was 2.28 : 1 and the mean number of mesiodens per one patient was 1.28. Conical shape was 84.4% and inverted orientation was 51.9%. There were more cases of anatomical structures encroachment, especially on the nasal floor and nasopalatine duct, when the mesiodens was not superimposed with the central incisor. There were, however, many cases of the nasopalatine duct encroachment when the mesiodens was superimpoised with the apical 1/3 of central incisor (52.6%). Delayed eruption (55.6%), crown rotation (66.7%) and crown resorption (100%) were observed when the mesiodens was superimposed with the crown of the central incisor. Conclusion : It is possible to predict three dimensional relationship between the impacted mesiodens and the maxillary central incisors in the panoramic images, but more details should be confirmed by the CT images when necessary.

• 대한소아치과학회지
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• 제33권1호
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• pp.109-115
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• 2006

석회화 치성낭은 상악 전치부에 호발하는 발육성 치성낭이나 조직학적 소견이 다양하고 따라서 분류 체계도 다양하다. 악골 내에서 느리게 진행되는 무통성 종창이 일반적이며 24-30%에서 매복치 및 치아종과 연관되어 나타난다. 피복 상피에 나타나는 유령세포는 결합 조직 에 노출되어 석회화 조직을 형성한다. 이 증례는 14세 여아의 상악 견치부에 발생한 치아종을 동반한 석회화 치성낭으로, 매복된 상악 좌측 견치 치관 주위로 경계가 명확한 방사선 투과성 병소와 다발성의 방사선 불투과성 석회화 물질이 혼재된 병소였다. 조직병리학적으로 중층 편평상피로 이장되어있고 상피 내에 유령세포가 관찰되었다. 석회화된 물질은 복합 치아종의 소견을 보여 Preatorius의 조직학적 분류에 의한 석회화 치성낭 Type IB로 진단되었다. 병소의 적출 및 병소에 이환된 견치 발치를 시행하였다. 현재 염증 소견이 관찰되어 병소에 이환된 상악 좌측 제1소구치는 치수치료를 시행하였으며 환아 및 보호자가 포괄적인 교정 치료를 원하여 현재 공간 유지 장치를 장착 중이다.

• Journal of Periodontal and Implant Science
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• 제36권2호
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• pp.461-471
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• 2006

In order to achieve a satisfactory esthetic result of periodontal surgery or implant in maxillary anterior area, periodontists must be aware of normal alveolar bone anatomy. The purpose of this study was to evaluate the relationship of alveolar bone morphology to tooth shape and form. 78(mean age : 25 yrs) periodontally healthy volunteers participated in this study. Two maxillary central incisor and one lateral incisor were selected to study. With minimal local anesthesia, gutta-percha cone inserted to labial gingival sulcus of selected teeth just after bone sounding with periodontal probe. Metal ball (4mm diameter) attached to palatal fossa of central incisor. Then, periapical radiograph was taken according to long cone paralleling technique. After film scan, labial alveolar bone profile reproduced along interproximal bone and apical ends of gutta-percha cones on computer screen. By utilizing computer program, the distance from height of interproximal bone to the labial bone crest in central incisor-central incisor and central incisor-lateral incisor area was measured and converted to real distance by using vertical length of metal ball on film. After measuring crown length & width of central incisor, the 10 individuals ranked lowest GW/L ratio (crown width/length ratio) and the 10 ranked highest were selected as having a long-narrow(group N), or a short-wide(group W) form of the central incisors. Means of the distance from height of interproximal bone to the labial bone crest of group N, W were calculated and compared by means of independent t-test. The results were as follows: 1. Mean distance from the height of the interproximal bone to the labial bone crest was $3.5{\pm}0.7mm$ between two central incisor, and $2.8{\pm}0.6mm$ between central and lateral incisor. 2. Mean GW/L ratio of group N was 0.57, and group W was 0.8. Mean distance from the height of the interproximal bone to the labial bone crest of group N was higher than group W in both measured area(measurements of group N, W were $3.9{\pm0.2mm$ and $3.5{\pm}0.2mm$ between two central incisor, $3.0{\pm}0.2mm$ and $2.8{\pm}0.2mm$ between central and lateral incisor), but there were no statistically significant differences when the groups were compared. Within the limits of the present study, there was a tendency that subjects with long-narrow teeth have more scalloped alveolar bone profile than subjects with short-wide teeth in upper anterior area, but no statistically significant differences were found.