• Restorative Dentistry and Endodontics
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• 제17권2호
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• pp.399-412
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• 1992

The purpose of this study was to evaluate the root canal transportation and remaining dentin / cementum thickness after using hand and ultrasonic instrumentation in the curved mesial root canals of extracted human mandibular molars. Fourty - six clear polyether blocks were made and randomly divided into two groups: hand instrumentation group with K - Flex files and ultrasonic instrumentation group with Suprasson SP unit. All root canals were instrumented to a size corresponding to a # 30 K - Flex file 1mm short from the radiographic apex. The roots were then sectioned perpendicular to the long axis so the apical and middle third could be evaluated with the Zoom stereomicroscope. The results were as follows : 1. In the total amount of removed dentin at middle third level, there was not significant difference between the hand instrumentation and ultrasonic instrumentation (P>0.05). 2. In the total amount of removed dentin at apical third level, there was more removed by the ultrasonic instrumentation than hand instrumentation(P<0.005). 3. In the transportation width, there was not significant difference between the two groups at both sectioned levels(P>0.05). 4. It was suggested that the canal was transported distally at middle third level and mesially at apical third level by booth techniques.

• Restorative Dentistry and Endodontics
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• 제14권1호
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• pp.189-197
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• 1989

The purpose of this study was to observe the resulting canal shape after using hand, sonic and ultrasonic instrumentation. Thirty canals from extracted human upper or lower 1st and 2nd molars were divided into 3 groups: hand, sonic and ultrasonic instrumentation group. 10 canals of each group were individually prepared with one of three instrumentation methods. After instrumentation and histological processing, apical, middle and coronal third cross sections were examined on the roundness of the canal by microscope. The result were as follows. 1. All experimented groups showed no significant difference in canal roundness regardless of size and level of the canal. 2. Sonic air instrumentation groups revealed Significantly better canal roundness than ultrasonic groups at the middle third of the fine canal. 3. In ultrasonic instrumentation groups, the roundness of the large canal was significantly better than that of fine canal.

• Restorative Dentistry and Endodontics
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• 제13권2호
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• pp.253-263
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• 1988

In order to study the cleansing effect of air-driven sonic system, the author prepared root canals on 48 extracted human permanent single rooted teeth using hand instrumentation and aforementioned method, half and half of the cases. In order for comparison of the degree of remnant debris and cleanliness, the cross sections at 3mm and 7mm levels from the apex were stereomicroscopically observed and scored in accordance with predetermined degree. The obtained results were as follows: 1. Air-driven sonic system was more effective in cleansing root canal than hand instrumentation at apical 3mm level. (p < 0.01) 2. Air-driven sonic system was more effective in cleansing root canal than hand instrumentation at apical 7mm level. (p < 0.01) 3. In hand instrumentation, Helisonic file was more effective in cleansing root canal than Rispisonic file. (p < 0.05) In air-driven sonic system, on the other hand, there were no significant difference between the two files.

• Journal of Periodontal and Implant Science
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• 제28권4호
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• pp.809-822
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• 1998

Adequate root preparation in the treatment of periodontal disease often involves mechanical instrumentation to remove plaque, calculus perhaps contaminated cementum. Although meticulous scaling and root planing may remove some cementum, the use of aggressive root planing to remove cementum does not appear warranted. So ultrasonic device and rotary instrument appear to be replacing hand instrument. But it is not clear those instruments make smooth root surface as hand instrument. The roghness of the root surface were evaluate with SEM following instrumentation with Gracey curette, Perio Clean and piezo ultrasonic device(Setlec) with various tip. 20 extracted teeth were used in vitro experiment, and 9 teeth of a patient destined for extraction for periodontal reasons were utilized in vivo experiment. It was demonstrated that hand curette created the smoothest surface, while diamond tip tended to roughen the root surface. But the hand curette, Perio Clean, and piezo ultasonic device with scaler tip tend to remove cementum completely. Piezo ultrasonic device with curette-like tip made the desirable smooth surface with partial removal of cementum.

• Restorative Dentistry and Endodontics
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• 제31권1호
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• pp.30-35
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• 2006

만곡근관에서 근관형성방법에 따른 근관작업장 변화를 평가하기 위하여 발거된 대구치의 협측 또는 근심 근관 40개에서 스테인레스-스틸 수동 파일 ($MANI^{(R)}$, 일본), 니켈-티타늄 수동 파일 (Naviflex $NT^{TM}$, 미국), ProFile, 또는 $ProTaper^{TM}$ (Dentsply-Maillefor, 스위스)를 사용하여 crown-down 방법으로 30번 크기까지 근관을 형성하고 근관형성 전후의 근관작업장 및 만곡도의 변화를 관찰하였다. 근단공에 대한 10-K파일 끝의 위치변화를 AutoCAD2000 (Autodesk 사, 미국)으로 측정하고 일원변량분석법 및 Tukey's studentized range test로 통계 분석하였다. 모든 군에서 근관형성후 근관장 및 만곡도가 유의하게 감소하였으며, 치관부 근관형성시 Gates Glidden bur를 사용한 수동파일 군이 ProFile 군보다 유의하게 많은 근관장 감소를 초래하였고, 치관부 및 근단부 전체 근관형성후에는 스테인레스 스틸 수동파일 군이 ProFile 군에서보다 유의하게 많은 근관장 감소를 나타내었다 (p<0.05).

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 D
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• pp.3041-3043
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• 2000

GUI(graphical user interface) has been the dominant platform for HCI(human computer interaction). The GUI-based style of interaction has made computers simpler and easier to use. However GUI will not easily support the range of interaction necessary to meet users' needs that are natural, intuitive, and adaptive. In this paper we study an approach to track a hand in an image sequence and recognize it, in each video frame for replacing the mouse as a pointing device to virtual reality. An algorithm for real time processing is proposed by estimating of the position of the hand and segmentation, considering the orientation of motion and color distribution of hand region.

• Restorative Dentistry and Endodontics
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• 제29권2호
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• pp.147-152
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• 2004

The purpose of this study was to investigate the quantity of debris which was extruded apically after canal instrumentation using different types of enlarging instrument in endodontic resin models. Five groups of 9 endodontic resin models were instrumented using each different technique : hand instrumentation without early coronal flaring. hand instrumentation after early coronal flaring. and three nickel-titanium engine-driven instrumentations (Hero 642, Protaper, $K^$). Debris extruded from apical foramen during instrumentation was collected on preweighed CBC bottle, desiccated and weighted using electronic balance. The results were analyzed using Kruskal-wallis test and Mann-Whitney U rank sum test at a significance level of 0.05. The results were as follows: 1. All of instrumentation techniques produced apically extruded debris. 2. Group without early coronal flaring extruded significant more debris than groups with early coronal flaring. 3. There was no significant difference among early coronal flaring groups. The early coronal flaring is very important to reduce the amount of debris extruded apically.

• 대한치과보존학회:학술대회논문집
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• 대한치과보존학회 2003년도 제120회 추계학술대회 제 5차 한ㆍ일 치과보존학회 공동학술대회
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• pp.580-580
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• 2003

I. Objectives This study investigated the quantity of debris which was extruded apically after canal instrumentation using different types of enlarging instrument in endodontic resin models. II. Materials and Methods Five groups of 9 endodontic resin model were instrumented using each different technique：hand instrumentation without early coronal flaring, hand instrumentation after early coronal flaring, and three nickel-titanium engine-driven instrumentations(Hero 642, Protaper, K3) after early coronal flaring.(omitted)

• 센서학회지
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• 제21권3호
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• pp.192-197
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• 2012

This paper describes the control of the hand fixing system attached to the finger rehabilitation robot for the rehabilitation exercise of patient's fingers. The finger rehabilitation robot is used to exercise the finger rehabilitation, and a patient's hand is safely fixed using the hand fixing system. In this paper, the hand fixing system was controlled with PD gains to fix a palm of the hand, and the characteristic test for the hand fixing system was carried out to sense the fixed hand movement of the front and the rear, that of the left and the right, and that of the upper. It is thought that the hand fixing system could safely fix the hand, and the movement of the fixed hand could be perceived using the five-axis force/moment sensor attached to the hand fixing system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 D
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• pp.3022-3024
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• 2000

Biometrics is the electronic recognition of individuals achieved through a process of extracting, and then verifying, features which are unique to that individual. This field is rapidly evolving technology that has to be widely adopted in a broad range of applications. Many methods have been studied such as extraction of the facial features, the voice, the vein and even a person's signature. Among biometrics, a hand veins provide large, robust, stable, hidden biometric features. Hand vein patterns have been proven to be absolutely unique by Cambridge Consultants Ltd. Because of this advantage, hand vein recognition are recently developing field in the field of a security.