불소적용시 법랑질과 상아질에서 불화칼슘형성의 차이에 관한 실험적 연구

김재곤,권선자,윤현두,안수현,백병주 大韓小兒齒科學會 1998 大韓小兒齒科學會誌 Vol.25 No.1

The purpose of this study was to compare the amount of calcium fluoride deposited on the enamel and dentin surface and to obtain information on the morphological change and crystallographic details of mineral deposition after 12,000ppm APF application in vitro. The bovine enamel and dentin blocks were randomly assigned to eight groups according to artificial caries lesion formation and difference of fluoride application time. The fluoride concentration and morphological characteristics on the treated enamel and dentin surface were investigated by using fluoride quantitative analysis and SEM. The powdered enamel and dentin of the intact bovine incisors were prepared for the X-ray diffraction analysis. The following results were obtained. 1. The amounts of KOH-soluble fluoride on the carious enamel and dentin surface after 24h APF application were higher than after only 5min APF application(P<0.05), but in the case of the sound enamel and dentin surface were similar after 5min and 24h application (P>0.05). The fluoride content was highly increased in the carious dentin as compared with sound dentin after APF application(P<0.05). 2. The caruous enamel surface after APF application, the demineralized enamel surface were recovered a more dense enamel surface and precipitation of crystal was observed a distintive surface layer of spherical globules of about 1 m diameter. In the case of the fluorided carious dentin surface, precipitation of calcium fluoride-like material was deposited both inside the dentinal tubules as well as in the intertubular regions. 3. The crystallographic structure of powdered enamel and dentin after 24h APF application had large crystallities of apatite and CaF2 diffraction peaks in the enamel as compared with dentin. The diffraction data collected from the 27.50-29.50(2) angular range of the powdered enamel, the (105) apatite, (225) apatite and (111) CaF2 peaks of the enamel crystallities were detected after 24h APF application.

저사이클 피로수명에 영향을 미치는 구상흑연주철의 흑연입자수의 영향

김민건,이병현,유병호 강원대학교 산업기술연구소 2000 産業技術硏究 Vol.20 No.B

Low cycle fatigue life of spheroidal graphite cast iron is determined by the morphological parameters of internal graphite. The aim of this study is to clarify the effect of the number of nodular grain of spheroidal graphite cast iron on low cycle fatigue life. Two specimens that have identical average nodular grain size by changing nodular grain volume fraction and different number of nodular grain count was tested. In this paper, the parameter governing fatigue life through fatigue test, the number of nodular grain seriously affect fatigue life and nodular grain size is no longer governing parameter of it.

Pendulum 장치를 이용한 상악 대구치 후방이동에 관한 치험례

김문현,백병주,이지연 大韓小兒齒科學會 1993 大韓小兒齒科學會誌 Vol.20 No.2

Orthodontists have long sought methods of correcting ClassⅡ malocclusions without straining the lower arch and without the need for strict patient compliance. In the 1990s, noncompliance therapies in various forms have become more prominent than ever before. The Pendulum Appliance is a hybrid that uses a large Nance acrylic button in the palate for anchorage, along with 032˝TMA springs that deliver a light, continuous force to the upper first molars without affecting the palatal button. Thus, the appliance produces a broad, swinging arc-or pendulum- of force from the midine of the palate to the upper molars. Since the Pendulum Appliance drives the upper molars distally (with slight lingual tipping) quite rapidly, there is a tendency for the anterior bite to open. This open bite generally corrects itself in brachyfacial types, especially those with tongue-thrust habits. I still recommend treating vertical growth patterns conservatively with extraction, directional headgears, and transpalatal bars. Patient tolerance of the Pendulum Appliance has been excellent; most adapt to the appliance within a week, Initial clinical findings have been encouraging. It is not unusual to see as much as 5mm of distal molar movement in three to four months.

사출성형 공정에 따른 Bobbin의 변형에 관한 연구

김병곤,민병현 동의대학교 산업기술개발연구소 2001 産業技術硏究誌 Vol.15 No.-

Warpage analysis of bobbin, molded by injection molding process was performed. Cooling system capable of the balance of polymer melt was designed based on Taguchi method, the distance between cavity wall and cooling channel was most influent factor amongst four design variables. Optimal packing process to reduce the warpage of molded part was analyzed based on the response surface method by considering holding time, persistence time up-to no-flow temperature, persistence time up-to ejecting temperature, and holding pressure. Optimal conditions of those were 9.4 seconds, 5.3 seconds, 15.2 seconds, and 85MPa, respectively.

하악골에 발생한 낭종에 관한 임상적 연구

김재곤,김미라,안수현,백병주 大韓小兒齒科學會 1997 大韓小兒齒科學會誌 Vol.24 No.3

Cystic lesions of the mandible are fairly common and usually a presumptive diagnosis is made readily, more often on the basis of roentgenographic appearance than by any other means. Occasionally, however, it is easy to fall into errors of diagnosis which may affect one's choice of treatment. The diagnosis in these situations are usually resolved by the histopathologic examination of material obtained by surgical exploration. The present discussion to the lesions which can be most easily confused in the roentgenographic interpretation, that is, the traumatic bone cyst, the dentigerous cyst, the radicular cyst. These lesions often grow to considerable size before they cause any subjective or objective symptoms. Less frequently, perhaps, the patient presents himself with the complaint of enlargement of the affected part, a discharge, or pain. On rare occasions the first sign is fracture through the cyst cavity. In any case, an adequate roentgenographic survey by means of extraoral films is essintial. This is the primary means of diagnosis. The three lesions in mandible, reported here, resembled each other roentginographically in that they were osteolytic lesions. THe follicular and radicular cysts usually have a smooth periphery and may be surrounded by a white line. The follicular cyst, slow-growing lesions, is usually associated with an unerupted tooth. The radicular cyst, the most common type of the odontogenic cyst, is always associated with a nonvital tooth, or it may persist as a "residual" radicular cyst after the causative tooth has been extracted. The traumatic bone cyst can often be differentiated from the first two in that the periphery is less definite and is irregular. It is thought that because it does not occur in older people, the lesion is self-limiting and heals spontaneously if left alone.

키 프레임을 이용한 동영상 검색에 관한 연구

김희수,김형균,전병균,이호현 광주보건대학 2004 論文集 Vol.29 No.-

The primary goal of video parsing is to accurately detect fast/gradual scene changes to index the video data so that future retrieval may be performed efficiently. Due to the sheer volume of the video data, however, the goal of accurate detection must be met by some real-time (fast) automatic (or at least semi-automatic) video parsing mechanism. For this purpose, I have developed a fast algorithm to detect gradual scene change and also detect camera motions to reduce false positives (falsely declaring a scene-change). In this dissertation, we propose a new approach that detects the change of scene which contains fast motion, zooming, dissolve in AVI video sequence. The proposed scheme adopts the feature matching technique which ALH(Average of Luminance Histogram) in each frame with those in the previous frame. Experimental results show that the proposed method performs better in detection scene changes than other conventional methods.

5급 복합레진충전된 치아에 있어서의 계면조건과 유지구의 영향에 대한 2차원유한요소법적 연구

김동호,유현미,조병훈 大韓齒科保存學會 1998 Restorative Dentistry & Endodontics Vol.23 No.2

소아에서 발생한 비치성 양성종양에 관한 임상적 연구

백병주,김문현,김재곤,허선,김영신 大韓小兒齒科學會 1998 大韓小兒齒科學會誌 Vol.25 No.2

Non-odontogenic tumors can be classified as malignant or benign. Most oral tumors in children are benign. In the Belfact series only 7.5 percent of soft tissue tumors were malignant and Bhaskar(1963) found only 9 percent of 293 oral tumors of all kinds to be malignant. Benign tumors may be classified as epithelial and mesenchymal. The most common tumor of surface epithelium is the squamous papilloma. These are easily recgnized clinically as cauliflower-like lesions. Fibrous lesions are very common in children's mouths. Many of these are not true neoplasms but are related to fibrous hyperplasia. Another common oral tumor in children is angiomatous tumor. Hemangioma occurred more frequently than lymphangioma. Cy stic hygroma, a cystic subtype of lymphangioma, is a developmental tumor of lymphatic origin. It is a considered to be a relatively rare lesion. about 50 precent of cystic hygroma are present at birth, and most of the remaining 50 percent appear in the early years of life during the period of active lymphatic growth. The preferred treatment for these lesions, except for hemangioma, is complete surgical excision. With proper surgical techniques, recurrence is not expected.

Stainless steel crown 순면위에 레진피복을 이용한 전치부 심미적 수복

안수현,김재곤,백병주,박종하 大韓小兒齒科學會 1997 大韓小兒齒科學會誌 Vol.24 No.4

Despite dentistry's attempts to improve the dental health of the public and to minimize the effects of caries, many children still present with extensive destruction of primary anterior teeth. One of dentistry's most challenging tasks is to repair these teeth with restoration which are durable, retentive, and esthetic. Esthetic restoration can often be achieved with polycarbonate crowns, strip crowns, conventional S-S crowns, open-faced S-S crowns, commercially veneered S-S crowns. But, all of these have limitation. Advances in restorative materials and metal-bonding procedures have made possible new restorative techniques that combine the advantages of S-S crowns with the cosmetics of composite restoration methods. The described technique of bonding composite to trimmed and fitted S-S crowns offers many advantages over other techniques currently used to restore primary anterior teeth. 1. If S-S crowns are accurate trimmed and contoured, good retention of crowns is achieved. 2. The patient time required is similar to that of conventional S-S crowns. 3. Good esthetics and high bond strengths are achieved. 4. It is possible to use this veneering technique intraorally on crowns that have fractured veneers.

산부식전 소와 열구 처리법에 따른 치면 열구 전색재의 변연 봉쇄성에 관한 연구

安帥炫,金秀也,白秉周 全北大學校 齒醫學硏究所 1993 전북치대논문집 Vol.11 No.1

The purpose of this study was to evaluate the marginal sealing of pit & fissure sealant according to the treatment of pit & fissure prior to acid etching in permanent premolar & molar. 20 premolars & 30 molars were used for experiment. They were classified into 5 experimental group at random : Group 1 was not treatment and Group 2, 3, 4, 5 were respectively treatment with pumice, small round steel bur of low speed handpiece, pointed diamond bur of high speed handpiece, Murakami R.I. No. 1-2. All the specimens were then thermocycled in a range of 4℃∼54℃ and immersed in 2% methylene blue dye solution for 24 hours and sectioned with low speed diamond cutter into two part under water condition. All the specimens were observed at pit & fissure-sealant interface with light microscope & statistical analysis was performed. The obtained results were as follows ; 1. There were significant increase in marginal sealing of high speed handipiece-pointed diamond bur group in contrast to pumice group at significant level α=0.05 when compared by dye penetration score(P<0.05). 2. There were significant increase in marginal sealing of low speed handpiece-small round steel bur group, high speed handpiece-pointed diamond bur group and Murakami R.I. No 1-2 group in contrast to pumice group at significant level α=0.01 when compared by dye penetration score(p<0.01.) 3. There were significant increase in marginal sealing of low speed handpiece-small round steel bur group, high speed handpiece pointed diamond bur group and Murakami R.I. No. 1-2 group in contrast to pumice bur group and Murakami R.I. No. 1-2 group in contrast to pumice group at significant level α=0.01 when compared by dye penetration length(p<0.01). 4. When compared by dye penetration score, it is lowest in high speed handpiece-pointed diamond bur group and lower in low speed handpiece-small round steel bur group, Murakami R.I. No. 1-2 group, pumice group, no treatment group in sequence. 5. There were better penetration force of pit and fissure sealant in low speed handpiece-small round steel bur group and high speed hdndpiece-pointed diamond bur group than no treatment group, pumice group and Murakami R.I. No. 1-2 group.