• Journal of Periodontal and Implant Science
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• 제39권2호
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• pp.111-118
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• 2009

Purpose: The integrity of interproximal hard/soft tissue has been widely accepted as the key determinant for success or degree of root coverage following the connective tissue graft. However, we reason that the gingival biotype of an individual, defined as the distance from the interproximal papilla to gingiva margin, may be the key determinant that influence the extent of root coverage regardless of traditional classification of gingival recession. Hence, the present study was performed with an aim to verify that individual gingival scalloping pattern inherent from biotype influence the level of gingival margin following the connective tissue graft for root coverage. Methods: Test group consisted of 43 single-rooted teeth from 21 patients (5 male and 16 female patients, mean age: 36.6 years) with varying degrees of gingival recession requiring connective tissue graft; 20 teeth of Miller class I and 23 teeth of Miller class III gingival recession, respectively. The control group consisted of contralateral teeth which did not demonstrate apparent gingival recession, and thus not requiring root coverage. For a biotype determination, an imaginary line connecting two adjacent papillae of a test tooth was drawn. The distance from this line to gingival margin at mid-buccal point and this distance (P-M distance) was designated as "gingival biotype" for a given individual. The distance was measured at baseline and 3 to 6 months examinations postoperatively both in test and control groups. The differences in the distance between Miller class I and III were subject to statistical analysis by using Student.s t-test while those between the test and control groups within a given patient were by using paired t-test. Results: The P-M distance at 3 to 6 months postoperatively was not significantly different between Miller class I and Miller class III. It was not significantly different between the test and control group in a given patient, either, both in Miller class I and III. Conclusions: The amount of root coverage following the connective tissue graft was not dependent on Miller's classification, but rather was dependent on P-M distance, strongly implying that the gingival biotype of a given patient may play a critical impact on the level of gingival margin following connective tissue graft.

• 대한치과교정학회지
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• 제27권5호
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• pp.815-824
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• 1997

본 연구는 최근 많은 연구가 행해지고 있는 유한요소를 이용한 교정시스템 구축에 있어서 정상교합자가 아닌 부정교합 환자별 유한요소 모델 구축을 위한 기초 알고리즘 개발에 그 목표가 있다. 기존에는 유한요소 분석을 위해서 한 환자의 치열을 유한요소 모델로 재현하고자 할 때, 전처리 과정에 대부분의 시간을 소요해야만 했다. 본 연구에서는 이 전처리과정을 자동화할 수 있는 기초 알고리즘을 마련하여, 향후 이 방면의 연구를 용이하도록 하였다. 이를 위하여 임의로 선택된 부정교합 환자의 상하악 모형을 이용하여 치아의 삼차원적인 위치를 계측할 수 있는 표준화된 방법을 제시하였으며, 또한 본 연구를 통하여 개발된 프로그램을 이용하여 유한요소의 전처리 과정을 자동화할 수 있는 기초를 마련하였다. 본 연구는 아래와 같은 단계를 거쳐 수행하였다. 1. 상,하악 중절치에서 제2대구치까지 14개의 치아 형상을 상,하악 각각 구축하여 개별 파일로 저장한다. 2. 이 치아에 standard bracket을 치관의 FA point와 bracket slot의 중앙이 일치되도록 부착한다. 3. 대상 환자의 석고 모형을 제작한다. 4. 석고 모형에서 본 연구를 위해 제작된 기구들로 치아의 crown inclination, angulation, 그리고 교합면에서 치관첨까지의 수직거리를 계측한다. 5. 표준화하여 촬영한 석고 모형의 사진을 이용하여 화상처리기법으로 치아의 치열궁 형태를 파악한다. 또한 사진상에서 치아의 수평적 위치 및 회전량을 측정한다. 6. 계측된 crown inclination, angulation, 수직거리, 그리고 치열궁의 형태 및 치아의 회전정 도 등을 회전행열을 이용하여 만든 프로그램에 입력한다. 이 프로그램은 유한요소 전처리 과정에 필요한 치아의 배열상태를 담고 있는 데이터를 결과 파일로 제공하는데, 이 결과 파일은 일반적인 상용 유한요소 프로그램에서도 사용 가능하다. 7. 개개의 치아 파일은 이 결과 파일에 따라 삼차원적인 위치로 배열되어 선택한 특정 환자의 유한요소 모델을 완성하게 된다. 상기와 같은 여러 단계를 거친 후 임의로 선택한 부정교합자의 상,하악 유한요소 모델 구축을 위한 기초 자료를 구축할 수가 있었으며, 개개인 환자의 모형에서 얻은 정보로 유한요소 모델로 재현하기 위한 전처리과정의 기초 알고리즘을 마련하였다.

• 대한치과교정학회지
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• 제39권2호
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• pp.105-111
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• 2009

법랑질 탈회는 교정 치료 중에 발생하는 대표적인 부작용으로서 특히 교정용 브라켓에 대한 세균 부착이 그 원인이 될 수 있다. 본 연구의 목적은 서로 다른 표면 특성을 가진 세 종류의 브라켓을 구강 내 장착했을 때 각 재료의 표면에 대한 mutans streptococci 부착 정도를 측정하여 브라켓 재료에 따른 법랑질 탈회 및 치아 우식 발생 가능성을 분석하는 것이었다. 상하악 및 치아 부위별 mutans streptococci 부착 정도의 차이를 배제하고 브라켓 원재료에 따른 차이만을 검출하기 위하여 균형완전블록 실험계획을 설계하였다. 피실험자인 30세 여성의 구강 내에 장착할 수 있는 tooth positioner 형태로 3세트의 플라스틱 맞춤 트레이를 제작하였으며, 이 트레이에 직육면체의 형태($4{\times}3{\times}2\;mm$)로 제작한 stainless steel, monocrystalline sapphire, polycrystalline alumina 조각을 세트마다 서로 다른 순서로 전치부와 구치부 순면에 부착하였다 이렇게 제작된 3종류의 실험장치를 12시간 동안 피 실험자의 구강 내에 장착한 후, 각 브라켓 재료 표면에 형성된 치태를 채취하여 bacitracin이 포함된 mitis salivarius배지에서 48시간 배양 후 colony counting을 통해 그 표면에 부착된 mutans streptococci 양을 비교하였다. 이와 같은 방법으로 3세트의 실험장치에 대해서 각각 5회씩 총 15회의 실험을 시행하였다. 그 결과 상하악 및 치아 부위별 및 브라켓 재료별 세균 부착 정도는 모두 유의한 차이를 보이지 않았다. 결론적으로 본 연구의 결과 in vivo condition에서 브라켓 재료의 차이는 mutans streptococci 부착에 영향을 미치지 못하는 것으로 보였다.

• 치위생과학회지
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• 제17권2호
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• pp.183-191
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• 2017

본 연구는 치과 임상의 예방진료실에서 임상예방진료를 받은 환자의 구강건강인식도, 지식도, 실천도, 만족도를 비교분석하였다. 구강건강지식, 인식, 실천은 임상예방진료 전후 유의한 차이가 있었다. 임상예방진료프로그램 중 가장 만족도가 높은 것은 계획단계의 개별 예방계획과 실행단계의 PTC였고, 그 다음으로 평가단계의 평가결과 알림이었다. 만족 이유는 의료진이 친절해서가 가장 높았고, 재방문 점수는 10점 만점에 9.34점, 지인 추천 점수는 9.75점이었다. 지인 추천과 정의 상관관계가 있는 것은 임상예방진료프로그램 중 치아확인, 사진촬영, 계획, PMTC, TBI, 평가였다. 위의 결과를 통해 치위생과정을 근거한 임상예방진료프로그램은 환자의 구강건강에 대한 지식, 인식, 실천에 긍정적으로 효과가 있었고, 임상예방진료프로그램에 대한 만족도가 높아 치과 재방문과 지인 추천에 긍정적인 효과가 있었다. 따라서 치위생과정을 근거한 임상예방진료프로그램을 예방진료실에서 적극 활용하여 널리 적용되기를 바란다.

• 대한치과보철학회지
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• 제62권1호
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• pp.6-19
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• 2024

Computer aided design/Computer aided manufacturing (CAD-CAM) 기술의 발전에 따라 이를 활용한 총의치 제작 방법이 대두되고 있으며, 그 중 하나로 의치상과 인공치의 색조를 모두 포함하는 모놀리식 블록을 절삭하는 디지털 의치 시스템이 소개되었다. 본 증례는 74세 남성, 73세 여성 두 환자에서 전통적인 기존 의치 제작법, 디지털 방식의 모놀리식 블록을 절삭한 의치 제작법으로 각각 총 두 쌍의 상·하악 의치를 제작하여 비교한 증례이다. 디지털 방식의 총의치 제작 과정으로는 CAD-CAM 프로그램으로 개인 트레이를 디자인 및 3D프린팅 하여 최종인상 및 악간 관계 채득하였다. 이후 동일한CAD-CAM프로그램으로 총의치 디자인 및 시적의치를 3D 프린팅 하여 시적 하였다. 최종적으로는 모놀리식 블록(Ivotion, Ivoclar Vivadent, Schaan, Liechtenstein)을 밀링 기계(PrograMill PM7, Ivoclar Vivadent, Schaan, Liechtenstein)로 절삭하여 총의치 제작 및 장착하였다. 해당 증례에서는 CAD-CAM 시스템을 이용한 총의치 제작과 동시에 전통적 방법으로도 총의치를 제작하여2쌍의 의치의 안정 및 적합성, 발음, 저작, 심미성과 환자의 만족도를 비교, 분석하여 이를 보고하고자 한다.

• 대한치과교정학회지
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• 제47권1호
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• pp.21-30
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• 2017

Objective: The aim of this study was to investigate the three-dimensional (3D) position of the center of resistance of 4 mandibular anterior teeth, 6 mandibular anterior teeth, and the complete mandibular dentition by using 3D finite-element analysis. Methods: Finite-element models included the complete mandibular dentition, periodontal ligament, and alveolar bone. The crowns of teeth in each group were fixed with buccal and lingual arch wires and lingual splint wires to minimize individual tooth movement and to evenly disperse the forces onto the teeth. Each group of teeth was subdivided into 0.5-mm intervals horizontally and vertically, and a force of 200 g was applied on each group. The center of resistance was defined as the point where the applied force induced parallel movement. Results: The center of resistance of the 4 mandibular anterior teeth group was 13.0 mm apical and 6.0 mm posterior, that of the 6 mandibular anterior teeth group was 13.5 mm apical and 8.5 mm posterior, and that of the complete mandibular dentition group was 13.5 mm apical and 25.0 mm posterior to the incisal edge of the mandibular central incisors. Conclusions: Finite-element analysis was useful in determining the 3D position of the center of resistance of the 4 mandibular anterior teeth group, 6 mandibular anterior teeth group, and complete mandibular dentition group.

• The Journal of Advanced Prosthodontics
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• 제8권3호
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• pp.201-206
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• 2016

PURPOSE. The aim of this study was to compare the radiopacity of 6 modern resin cements with that of human enamel and dentine using the Digora digital radiography system, to verify whether they meet the requirements of ANSI/ADA specification no. 27/1993 and the ISO 4049/2000 standard and assess whether their radiopacity is influenced by the thickness of the cement employed. MATERIALS AND METHODS. Three 3-thickness samples (0.5, 1 and 1.5 mm) were fabricated for each material. The individual cement samples were radiographed on the CCD sensor next to the aluminium wedge and the tooth samples. Five radiographs were made of each sample and therefore five readings of radiographic density were taken for each thickness of the materials. The radiopacity was measured in pixels using Digora 2.6 software. The calibration curve obtained from the mean values of each step of the wedge made it possible to obtain the equivalent in mm of aluminium for each mm of the luting material. RESULTS. With the exception of Variolink Veneer Medium Value 0, all the cements studied were more radiopaque than enamel and dentin (P<.05) and complied with the ISO and ANSI/ADA requirements (P<.001). The radiopacity of all the cements examined depended on their thickness: the thicker the material, the greater its radiopacity. CONCLUSION. All materials except Variolink Veneer Medium Value 0 yielded radiopacity values that complied with the recommendations of the ISO and ANSI/ADA. Variolink Veneer Medium Value 0 showed less radiopacity than enamel and dentin.

• 치과방사선
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• 제24권1호
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• pp.85-94
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• 1994

The purposes of this study were clinical comparison and evaluation between digital radiography and conventional radiography for the detection of artificial interproximal caries. Four freshly extracted, unrestored posterior teeth were obtained and caries was simulated by drilling semicircled defects with variable size at the interproximal surface of each tooth. The experiments were performed with IBM-PC/32 bit-DX compatible, video camera(VM-S8200, Hitachi Co., Japan), and color monitor(Multisync 3D, NEC, Japan). Sylvia Image Capture Board for the ADC(analog to digital converter) was used, and spatial resolution was 512 × 480 with 256 gray levels. The obtained results were as follows: 1. At the condition of under exposure, the radiographs were superior to the digital images in readability. Also, as the size of the artificial lesion was increased, readability of the radiographs was elevated. 2. The digital images were superior to the radiographs in readability especially under over exsposure. 3. As the exposure time and size of lesion was increased, the gray level of region of interest of the digital image was decreased proportionally. 4. As the F-value of average gray level of region of interest at individual exposure time and size of lesion, gray level of the all lesion sizes was decreased in comparison with that of the normal enamel.

• Child Health Nursing Research
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• 제15권2호
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• pp.201-209
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• 2009

Purpose: This quasi-experimental study was conducted to identify the effects of dental health education on dental health knowledge and dental hygiene status in preschoolers. Methods: Forty-one children were recruited from two daycare centers, one of which served as the experimental group and the other as the comparative group without dental health education. Dental health education consisted of knowledge-oriented lecture and individual practice with a tooth simulator. The dental health knowledge was measured using a self-report questionnaire and dental hygiene using a dental plague index. The measurements were taken before and after the education program in the experimental group while only before the education program in comparative group. Results: Increases in dental health know ledge and decreases in dental plague index were observed 4 days after the education and lasted at least 8 days after the education, Conclusion: The findings of this study indicate that dental health care education consisting of a lecture with simulation practice can be effective in improving dental health care in preschoolers at day care center.

• Journal of Preventive Medicine and Public Health
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• 제19권1호
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• pp.100-122
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• 1986

Obtaining an available information on health concerns of parents of school-age children and furthermore developing the sound policy for the public on health education, this study was conducted during Nov.-Dec. 1985 in the four selected areas; Seoul, large, middle and small city, and farming and fishery villages for 3,337 parents of schoolchildren in Korea. In this study, parents complected a questionnaire containing 34 items related to health concerns(e.g. drinking alcohol, air pollution, cancer, etc. see Table 4 and Fig. 2). For each health items, respondents were asked to indicate a choice between three levels of concern; 'Very high concern,' 'Moderate concern,' 'Little concern', and 'No opinion'. An analysis of responses indicated that most of the top ten health concerns identified by parents as cancer, abortions among high school students, medical malpractice, water pollution, traffic accidents, air pollution, suicide of parents and homicide of offspring, heart disease, venereal diseases, and high blood pressure in that order. Those health problems about which respondents were least concerned were more closely related to the individual, such as drinking alcohol, smoking, tooth decay, gum disease, underweight, overweight. Of greater concern were more such as water pollution, abortions among high school students, air pollution, accidents, medical malpractice. For cancer, heart disease, high blood pressure, various accidents, environmental pollution, parents showed high concern, however, for health issues which contributed as causative influences such as lung cancer from smoking and liver cirrhosis and traffic accidents from drinking alcohol showed less concern. Relationship between parent's residential areas, educational level and sex distribution and health concern showed little difference, however, for these issues parents identified as relatively high concern. Most parents stowed more concern in sex-related of family-related health issues such as abortions among high school students, suicide of parents and homicide of offspring.