• Restorative Dentistry and Endodontics
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• 제41권2호
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• pp.143-147
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• 2016

The reconstruction of structurally compromised posterior teeth is a rather challenging procedure. The tendency of endodontically treated teeth (ETT) to fracture is considerably higher than vital teeth. Although posts and core build-ups followed by conventional crowns have been generally employed for the purpose of reconstruction, this procedure entails sacrificing a considerable amount of residual sound enamel and dentin. This has drawn the attention of researchers to fibre reinforcement. Fibrereinforced composite (FRC), designed to replace dentin, enables the biomimetic restoration of teeth. Besides improving the strength of the restoration, the incorporation of glass fibres into composite resins leads to favorable fracture patterns because the fibre layer acts as a stress breaker and stops crack propagation. The following case report presents a technique for reinforcing a badly broken-down ETT with biomimetic materials and FRC. The proper utilization of FRC in structurally compromised teeth can be considered to be an economical and practical measure that may obviate the use of extensive prosthetic treatment.

• 보건의료산업학회지
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• 제7권1호
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• pp.95-105
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• 2013

The purpose of this study is to examine the relationship between characteristics of obesity and oral diseases by sex and grade. To achieve this, a survey was carried out on 830 students at just an elementary school in Chungnam area. The results of this study are as follows. First, the relationship between dental caries and malocclusion prevalence according to obesity by sex and grade showed that there was no difference between dental caries and malocclusion prevalence by sex, and dental caries prevalence by grade. Second, the difference in the level of dental health according to obesity showed that overweight students had more both caries teeth and loss teeth than normal students. Third, the relationship between obesity and the level of dental health showed that overweight students had many caries teeth and loss teeth. In particular, obesity had higher relationship with caries teeth than loss teeth. As the childhood is the period of time when the range of socialization is extended to schools from families, schools are important life zones for children. Consequently, the continuous and intensive instruction of health problems in schools needs to be comprehensively approached in terms of education.

• 대한치과기공학회지
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• 제8권1호
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• pp.23-29
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• 1986

One of the primary advantage of acrylic resin teeth is their ability to bond chemically to the denture base resins. But, occasionally, failure have been observed in which acrylic resin teeth break lose from the denture, indicating that chemical bonding does not always occur. The most probable explanation for this type of failure was the presence of a trace of wax remaining as a residue on the surfaces of the teeth after the boiling-out procedure which adgered to the tooth surface and prevented bonding. The purpose of this stdy was preparing the specimens of denture base resin with acrylic resin teeth that four treatment method to ridge lap portion of the tooth and investigated bond between the teeth and denture base resin with tensile strength. Compared results of tensile strength on test specimens were as follows: 1. The mean of strength among the four test groups showed the difference was significant enough(P 0.01). The order of its strength mean was methylene chloride treatment group, detergent solution treatment group, kerosene-ether treatment grgoup, boiling water only group. 2. In compared results between the wax eliminating method groups, there were significant difference between the boiling water only group and other groups(P 0.01), no significant difference were found in the wax eliminating method groups except boiling water only group(P 0.05).

• 대한치과기공학회지
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• 제43권3호
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• pp.84-92
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• 2021

Purpose: The purpose of this study was to compare the dimension safety evaluation between a general ultrasonic cleaner and an ultrasonic cleaner equipped with UV-C (ultraviolet-C). Methods: An edentulous model was prepared. A denture base and an occlusal rim were fabricated, and scanning was performed. After scanning, a denture base and full arch artificial teeth were designed. The full arch artificial teeth were printed using a three-dimensional printer (n=10). The residual resin was washed with alcohol and then scanned (reference data). The printed specimens were classified and cleaned using a general ultrasonic cleaner (GU group) and an ultrasonic cleaner equipped with UV-C (UC group). After each washing, a rescan was performed (scan data). Reference data and scan data were superimposed using overlapping software. Data were statistically analyzed using the Mann-Whitney test (α=0.05). Results: In the deviation values of full arch artificial teeth, the GU group showed a high deviation of 18.02 ㎛ and the UC group showed a low deviation of 15.02 ㎛. The two groups demonstrated a statistically significant difference (p<0.05). Conclusion: Full arch artificial teeth prepared using photopolymerized resin were deformed according to the temperature of water generated in the ultrasonic cleaner. It is judged that there is no deformation according to the UV-C ultrasonic cleaner.

• 전기전자학회논문지
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• 제22권4호
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• pp.1206-1209
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• 2018

단층권을 갖는 12-Slot 10-Pole 영구자석 동기전동기는 고신뢰성이 요구되는 자동차 전기조향장치 시스템용으로 응용되고 있다. 하지만, 권선이 감겨져 있는 치에는 전류에 의한 기자력이 집중되는 구조이기 때문에 자기회로의 포화로 인한 기자력 감소가 발생하고, 이는 전동기의 성능을 저하시키게 된다. 본 논문에서는 이와 같은 단점을 개선하기 위해 고정자에 비대칭 치폭을 제안하고, 다양한 치폭 비 변경에 따른 전동기의 특성을 정밀 해석한다. 그 결과, 단층권을 갖는 자동차 전기조향장치용 PMSM 설계 시 특성 측면에서 가장 효율적인 치폭 비를 제시한다.

• 구강회복응용과학지
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• 제21권2호
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• pp.105-111
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• 2005

It is essential to establish the suitable position for artificial maxillary anterior teeth, because of not only esthetics, phonetics, mastication, but also optimal position of artificial posterior teeth for the construction of functional and esthetic prostheses. Anatomic landmarks have been used in the arrangement of artificial teeth. Such as incisive papilla and palatal rugae are useful landmarks for positioning occlusal rim and upper anterior artificial teeth because they are relatively stable and to be identified on master cast. Therefore, if average distance between maxillary anterior teeth and landmarks in dentate subjects are measured and applied, appropriate position of occlusal rim can be initially established. In this study, to present a guide to the position of the occlusal rim for upper anterior teeth of edentulous patients, horizontal distance between anatomic landmarks were measured. Maxillary casts were made in 72 Korean dentate subjects. Horizontal distance between central incisor and incisive papilla, between incisive papilla and intercanine line, and between primary palatine rugae and gingival margin of canine were measured on each cast. The results of this study were as follows ; 1. The mean distance from the incisal edge of central incisor to the posterior border of incisive papilla was 12.1 mm (Male 12.2 mm, Female 11.9 mm). 2. The mean distance between posterior border of incisive papilla and intercanine line was 3.5 mm (Male 3.4 mm, Female 3.6 mm / Left 3.6 mm, Right 3.4 mm). 3. The mean distance from the palatal gingival margin of canine to the lateral border of primary palatine rugae was 2.4 mm (Male 2.4 mm, Female 2.4 mm / Left 2.4 mm, Right 2.3 mm). 4. On all measured items, there were no significant differencies in measured values between male and female, and between left and right sides. (P>0.05).

• 대한치과교정학회지
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• 제31권2호통권85호
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• pp.209-223
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• 2001

치조골 결손을 갖는 환자의 상악전치부 압하(intrusion)시 필수적인 pure intrusion을 위해 three-piece base arch appliance와 후방견인력의 적용이 필요하게 된다. Three-piece base arch appliance를 적용한 상악전치부 압하시의 상악 6전치, 치근막 및 치조골의 3차원 유한요소모델을 제작하였다. Three-piece base arch appliance를 이용한 상악 전치부압하시 치아 수에 따른 저항중심의 위치, 치조골 흡수에 따른 pure intrusion을 위한 후방견인력 변화 양상, 그리고 이때의 치조골 높이에 따른 저항중심의 수직적, 수평적 위치 변화의 상관관계에 대해 다음과 같은 결과를 얻었다. 1. 치축 경사도와 치조골 높이가 정상이고, 압하시 three-piece base arch appliance를 이용한 경우 압하 하중점이 전후방적으로 저항중심을 통과하기 위한 조건은 다음과 같다. 1) 2 전치군(중절치군)을 대상으로 한 경우에는 중절치 브라켓 원심면에서 후방 6mm 지점으로, 측절치 브라켓 전방 1/3부위에 위치 하였다. 2) 4 전치군(중절치와 측절치군)을 대상으로 한 경우에는 측절치 브라켓 원심면에서 후방 5mm지점으로, 측절치와 견치 브라켓 사이 공간의 후방 2/3부위에 위치하였다. 3) 6 전치군(중절치, 측절치와 견치군)을 대상으로 한 경우에는 견치 브라켓 원심면에서 후방 7mm 지점으로, 제 1소구치 브라켓 중앙부위에 위치하였다. 4) 치아 수 증가에 따른 저항중심의 후방이동을 관찰할 수 있었고, 4 전치군 보다 6 전치군에서 후방 이동량이 크게 나타났다. 2. 치조골 높이가 정상일 때, pure intrusion을 위한 후방견인력을 적용할 경우 수직 압하점은 저항중심과 같거나 약간 전방에 위치했다. 3. 동일한 압하력과 압하점 적용시 치조골 상실 증가에 따른 압하시 pure intrusion을 위한 후방견인력 변화는 다음과 같다. 1) 2 전치군과 4 전치군의 후방 견인력은 6 전치군의 후방 견인력에 비해 낮게 나타났다. 2) 치조골이 상실됨에 따라 각 치아군 후방견인력은 증가됨을 보였다. 4. 상악 전치부 치아군과 치조골 높이에 따른 저항중심의 수평적, 수직적 위치간 상관관계는 다음과 같다. 1) 2 전치군일 때, 치조골 상실에 따른 저항중심의 수직적 위치변화에 대한 수평적 위치 변화가 가장 크게 나타났다. 치아 수가 증가할수록 치조골 상실에 따른 저항중심의 수직적 위치 변화에 대한 수평적 위치변화는 작아지는 경향을 보였다. 2) 치조골 상실량이 커짐에 따라서는, 치아 수에 관계 저항중심의 수직적 위치변화에 대해 수평적 위치변화가 커졌다.

• 대한한방내과학회지
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• 제16권2호
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• pp.146-177
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• 1995

The purpose of this study was to investigate the relationship between the teeth and Zhang-Fu(臟腑), dental diseases, and the hygiene of the mouth through the literature of oriental medicine. First, the relatonship between the teeth and Zhang-Fu is reviewed as follows: The teeth are influenced by Shen(腎) because they are the end of bone and Biao(標) of Shen. Gingiva is related to Wei(胃) and Da-Chang(大腸) because it is passed by Yangming-Channel(陽明經). The growth and nutrition of teeth depends on Shen. The pathological condition of Shen causes the gingival atrophy, the loose of teeth, dedentition due to aging, withering of teeth, and tartar: whereas the pathological condition of Wei and Da-Chang causes toothache, gingivitis, inflamed gums, bad breath, and gingival hemorrhage. Second, the causes and therapies of dental diseases through the literature can be summarized as follows: The major causes of toothache are the pathogenic condition of wind-heat and wind-cold, the heat syndrome of Wei, the damp-heat of intestine, flaring-up of fire of deficiency type, rotten tooth, etc... The principal causes of dedentition and the shaking and loose of teeth are the deficiency of Shen, and the rest of causes are the damp-heat of Yangming. Gingival atrophy is caused by the deficiency of Shen, whereas the gingival hemorrhage comes from the factors in the pathogenic factor of wind-heat of Yangming-Channel, the heat syndrome of stomach, and the deficiency of Shen. The causes of grinding of teeth during sleeping are stomach-heat, and the delayed dentition and the withering result from the deficiency of Shen-Jing.(腎精) The principal therapies of toothache are removing wind and heat, clearing away heat and prompting diuresis, clearing away the stomach-heat, replenishing vital essence to tonify the Shen, relieving superficial syndrome by wind-cold, and alleviating pain by destroying parasites. For the prescription of the principal therapies, there are Xijio Dihuang Tang, Jiajian Ganlu Yin, Qufeng Wan, Qingwei San, Tiaowei Chenggi Tang Shengong Wan, Liangge San Qingwei Tang Yunu Jian, Liuwei Dihuang Wan Zuogui Yin Bawei Wan Wanshao Dan, Xixin San Badou Wan Gianghuo Fuzi Tang, Jiuzi Tang Badou Wan, etc... The therapies of dedentition and the shaking and loose of teeth are replenishing vital essence to tonify the Shen, and warming and recuperating the Shen-Yang: as the prescription, there are Liuwei Dihuang Wana Zuogui Yin, and Bawei Wan Anshen Wan Wanshao Dan Yougui Wan etc... The therapies of gingival hemorrhage are clearing away the stomach-heat, replenishing vital essence to tonify the Shen, warming and recuperating the Shen-Yang(腎陽), and moisturing and purging intence heat with the prescription of Tiaowei Chenggi Tang Xijiao Dihuang Tang, Liuwei Dihuang Wan Zuogui Yin, Bawei Wan Anshen Wan, and Yunu Jian. The therapy of gingival atrophy is replenishing vital essence to tonify the Shen in the prescription of Liuwei Wan Bawei Wan Ziyin Dabu Wan. The therapies of grinding of teeth during sleeping are clearing away the stomach-heat and purging intense heat, and invigorating the spleen through eliminating dampness in the prescription of Qingwei San, Wumei Wan, etc... The therapy of delaed dentition is replenishing vital essence to tonify the Shen with the prescription of Liuwei Wan Buyin Jian, etc... Third, clinical treatment reports of dental diseases are reviewed as follows: The toothache due to stomach-heat was treated by medical herbs like Gypsum, Natrir Sulfas, Rehmanniae, Schizonepetal Herba, Menthae Folium, Cimicifugae Rhizoma, and Scrophulariae Radix. The therapies of toothache due to flaring-up of fire in deficiency type from deficiency of Shen provided with replenishment of vital essence to tonify the Shen and clean ministerial fire, and the prescription was the kind of Liuwei Wan, which worked very well. The therapy of dedentition and loose of teeth due to deficiency of Shen was done to stablize the teeth as tonifing the Shen with the prescription of Guchi Wan. The rate of imrovement was over 90%. The destruction of periodontal tissue due to periodonititis was cured of dispelling wind, reducing heat, and alleviating pain, It was improved by taking Zizhi Xingiong Tang, Guchi Xiaotong San, Yunii Jian, and Qingwei San about 3-7 days, and the rate of improvement was over 80%. Fourth, the prevention and regimens are reviewed as follows: As a physical and breathing exercise of the teeth, tapping teeth which stimulates the circulation of Qi(氣) and Xue(血) had been used. The tapping time of 14, 17, 36, etc... has been reported, and it should be applied based on the body condition. The medical herbs for gargling and brushing teeth have been used. Specifically, Cimicifugae Rhizoma, Gypsum, Gypsum Fibrosum, and Indigo pulrelrata Lereis have been used to reduce heat, Coptidis Rhizama and Yang Jinggu to eliminate damp-heat, Amomi Semen, Cyperi Rhizoma, Flos Caryophylli, Asari Radix, Piperis Longi Fructus, Santali Albae Lignum, Meliae Fructus, Moschus, Aquillaiae Lignum, and Borneol to promote the circulation of Qi and to relieve pain, Ligustici Radix, Angelice Radix, Rhizoma Nardostachydis, Tribuli Semen to relieve superficial syndrome by means of diaphiresis, and Cnidii Rhizoma, Angelicae sinensis Radix, and Olibanum to promote blood circulation to stop pain.

• 치위생과학회지
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• 제11권3호
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• pp.181-187
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• 2011

이 연구는 일부 대도시지역 다문화가족 이주여성의 구강건강과 관련된 삶의 질 간의 관련성을 알아보고자 대구지역 다문화가족 이주여성을 대상으로 구강검사와 개별면접조사를 통하여 인구사회학적 특성, 구강건강상태, OHIP-14를 측정하였다. 최종 수합된 189명의 자료로 t-검정 및 분산분석, 이분형 로지스틱 회귀분석을 이용하여 분석한 결과 다음과 같은 결론을 얻었다. 1. 평균 우식치아는 2.23개, 상실치아는 1.48개, 처치치아 5.58로 필리핀에서 온 여성이 기타 다른 나라에서 온 여성보다 상실치아수가 많았으며, 중국에서 온 여성이 충전영구치의 수가 상대적으로 낮았다. 2. 구강건강관련 삶의 질은 상실치아가 많을수록 낮았다.3. 상실치아의 여부에 따른 구강건강관련 삶의 질을 비교해 본 결과 정신적 불편, 신체적 능력저하, 정신적 능력저하, 사회적 능력저하, 사회적 불리 영역에서 구강건강관련 삶의 질이 가장 낮았다. 4. 구강건강관련 삶의 질은 우식경험영구치가 많을수록, 월 가구 수입이 낮을수록 낮게 나타나 우식경험영구치와, 월수입이 구강건강관련 삶의 질에 가장 큰 연관성이 있었다. 다문화가족 이주여성의 구강건강관련 삶의 질은 상실치아 및 우식치아가 많을수록 낮아 다문화가족 여성의 구강건강관련 삶의 질을 향상시킬 수 있는 프로그램을 개발하여 그 효과를 검증하는 후속 연구를 시도해야 할 것이다.

• 구강회복응용과학지
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• 제22권2호
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• pp.173-180
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• 2006

Objectives The aim of this study is to compare the quality of root canal preparation completed using MFile-$System^{(R)}$ instrument ( Komet, Gebr.Brsaseler, Germany) and conventional stainless steel file in the canals of Maxillary molar teeth that had a canal curvature between $25^{\circ}$ or more Materials & Methods Buccal canals of 24 first and second maxillary molar teeth, extracted for periodontal and prosthetic reasons were used. Tissue fragments and calcified debris were removed from teeth by scaling and the teeth were stored in 10% formalin solution for 24 hour. Then, teeth were stored in saline until used. To be included the roots had to have completed formed apices and angle of curvature ranging between $25^{\circ}$ or more according to the criteria described by Schneider(1971). Palatal and Second mesiobuccal canals were not included. Teeth were embedded into transparent acrylic. The teeth were randomly divided into two experimental groups. All teeth were scanned by Dental CT (PSR9000N, Asahi, Japan) to determine the root canal shape before instrumentation. Image slices were prepared from the apical end point to the pulp chamber. The first two sections were 2 mm from the apical end of root and 2 mm below the orifice. Further section was recorded, dividing the distance between the sections of apical and coronal levels into two equal lengths. 12 teeth were instrumented using stainless steel fileand another 12 teeth were instrumented using MFile-$System^{(R)}$. Following the completion of the instrumentation, the teeth were again scanned and compared with the cross sectional images taken prior to canal preparation. Amount of transportation and centering ability was assessed. Student's t-test was used for statistical analysis. Result Less transportation occurred with MFile-$System^{(R)}$ rotary instrumentation than stainless steel instrument. MFile-$System^{(R)}$ had better centering ability than stainless steel instrument. Conclusion MFile-$System^{(R)}$ rotary instrumentation transported canals less and had good centering ability.