폴리에스테르 섬유 감량시스템용 프로세서 타이트레이터 개발

조진호,이흥락,이종현,김명남,구성모,김무영,진경찬,유병희,강민수,김국진 경북대학교 센서기술연구소 1993 연차보고서 Vol.1993 No.-

폴리에스테르 섬유 감량시스템의 제어를 위해서는 처리조 내에서 감량되는 섬유가 목표 감량치에 도달했는지를 판단해 주는 장치가 필요하다. 본 연구에서는 가성소다용액의 초농도 및 섬유 감량 정도의 정확한 측정과 감량 종료시간의 산출 및 이에 따른 종료신호를 발생할 수 있는 폴리에스테르 섬유 감량기 전용의 자동적정장치를 개발하였다. To control caustic soda treatment system for the polyester fabric reduction, we need the device to determine that the fabric has been arrived target reduction value. In this study, we develope an automatic process titrator for the caustic soda treatment system. Major functions of the target titrating system are accurate measurements of the caustic soda concentration and then producing the end point signal for caustic soda treatment system.

대구치에서 회전식 NiTi file의 수명과 파절양상

김진우,안병두,박세희,신혜진,조경모 大韓齒科保存學會 2005 Restorative Dentistry & Endodontics Vol.30 No.3

Intracanal separation of the rotary files is a serious concern in modern endodontic practice. The objective of this study was to compare the life span and fracture patterns of three NiTi rotary files in molar teeth. Mesiobuccal roots of upper molar (n = 150) and mesial roots of lower molar (n = 150) were divided into three groups and each group was prepared with Profile, ProTaper, and K3 respectively. Every file was used until separation and/or deterioration of the cutting blade was happened, and then the number of canals to separation and/or unwinding were recorded. Radiographs and Scanning electon microscope (SEM) photographs were taken to evaluate the patterns of separation. The results were as follows: 1. There were no significant differences in numbers of canals to separation and/or unwinding among the groups. 2. Comparing between flaring files, K3 showed significant lower numbers of canals to separation and/or unwinding (p < 0.05), and there was no significant difference between shaping files 3. Separations of instruments were occurred at the midpoint of curvatures within the canals 4. In SEM observations, ductile fractures were seen in most of cases, characterized by shallow dimples. Additional researches is needed to provide a new guideline that informs the appropriate number of times to use NiTi files. 회전식 NiTi file은쉽게 파절되는 단점이 있으나 이에 대한 연구는 아직 부족하다. 본 연구에서는 회전식 NiTi file을 이용해 실제 치아에서 근관을 형성하고, 이 때 발생하는 파절 및 변형을 연구, 분석하였다. 상악 대구치의 근심협측 치근 (n = 150)과 하악 대구치의 근심치근 (n = 150)을 실험대상으로 하여 Profile, ProTaper 및 K3로 각각 근관형성 하였다. 각 file은 파절되거나 변형이 생길 때까지 계속하여 사용한 다음 그 사용횟수를 기록하였다. 파절의 양상을 관찰하기 위해 방사선 및 주사현미경 사진을 촬영하였다. 1 세 군간의 유의할만한 사용횟수의 차이는 없었다. 2. Flaring file 간의 비교에서는 K3의 사용횟수가 통계적으로 유의성 있게 적었으며 (p < 0.05), shaping file 간에는 유의할만한 차이가 없었다. 3, 회전식 NiTi file의 파절은 근관의 최대 만곡부에서 발생하였다. 4. 주사전자현미경으로 파절면을 관찰한 결과 연성파괴의 전형적인 양상인 얕은 딤플이 관찰되었다. 일반적으로 회전식 NiTi file의 평균 사용횟수는 제조회사의 사용지침보다는 길었으며, NiTi file의 수명에 대한 새로운 사용지침을 만들기 위한 부가적인 연구가 있어야 되리라 사료된다.

병렬 GHT 모델을 이용한 다중형태인식

金鎭浩,趙三模,高昌林 慶一大學校 1993 論文集 Vol.9 No.1

A parallel GHT model is introduced which can detect multiple shapes simultaneously with an efficient use of Hough space and modification of its accumulation method. In this method, we separated the Hough space into two and accumulated the evidences of reference points in two directions of up and down. The proposed model is implemented on the Transputer system and the resulted system proves to have simultaneous rotation-and scaling-invariant detection capability for four different shapes.

수종의 자가 접착 레진 시멘트의 물성 및 lithium disilicate ceramic과 상아질에 대한 전단결합강도 비교

신혜진,송창규,박세희,김진우,조경모 大韓齒科保存學會 2009 Restorative Dentistry & Endodontics Vol.34 No.3

본 연구의 목적은 치면 처리와 수복물 내면의 처리가 필요 없는 자가 접착 레진 시멘트의 물성 및 lithium disilicate ceramic과 상아질에 대한 전단결합강도를 측정하고 기존의 레진 시멘트와 비교하여 임상적 유용성을 알아보고자 하는 것이다. 실험군인 자가 접착 레진 시맨트로는 Rely-X Unicem, Embrace Wetbond, Maxcem, BisCem을, 대조군으로는 기존의 레진 시멘트인 Rely-X ARC, 수복용 복합레진인 Z-350을 사용하였다. 각 레진 시멘트의 물성 평가를 위하여 테플론 주형을 이용하여 시편을 제작하고 만능 시험기를 이용하여 압축강도, 간접인장강도, 굴곡강도를 측정하였다. IPS Empress 2 및 상아질 시편에 제조사의 지시대로 Rely-X ARC군과 Z-350군에만 전처리를 시행 후 각 시멘트를 접착하고 전단결합강도를 측정하였다. 실험 결과는 다음과 같았다. 1. 자가 접착 레진 시멘트인 Biscem이 가장 낮은 물리적 성질을 나타내었다 (P<0.05). 2. 자가 접착 레진 시멘트의 상아질 및 도재에 대한 전단결합강도는 기존의 레진 시멘트에 비해 유의성 있게 낮은 값을 나타내었다 (P<0.05). 이상의 결과로 볼 때 자가 접착 레진 시멘트는 기존의 레진 시멘트에 비해 물리적 성질 및 상아질과 lithium disilicate ceramic에 대한 전단결합강도가 떨어지는 것으로 사료된다. The purpose of this study was to evaluate the physical properties of different self-adhesive resin cements and their shear bond strength on dentin and lithium disilicate ceramic and compare these result with that of conventional resin cement. For this study, four self-adhesive resin cements (Rely-X Unicem, Embrace Wetbond, Mexcem, BisCem), one conventional resin cement (Rely-X ARC) and one restorative resin composite (Z-350) were used. In order to evaluate the physical properties, compressive strength, diametral tensile strength and flexural strenth were measured. To evaluate the shear bond strength on dentin, each cement was adhered to buccal dentinal surface of extracted human lower molars. Dentin bonding agent was applied after acid etching for groups of Rely-X ARC and Z-350. In order to evaluate the shear bond strength on ceramic, lithium disilicate glass ceramic (IPS Empress 2) disks were prepared. Only Rely-X ARC and Z-350 groups were pretreated with hydrofluoric acid and silane. And then each resin cement was adhered to ceramic surface in 2 mm diameter. Physical properties and shear bond strengths were measured using a universal testing machine. Results were as follows 1. BisCem showed the lowest compressive strength, diametral tensile strength and flexural strength. (P<0.05) 2. Self-adhesive resin cements showed significantly lower shear bond strength on the dentin and lithium disilicate ceramic than Rely-X ARC and Z-350 (P<0.05) In conclusion, self-adhesive resin cements represent the lower physical properties and shear bond strength than a conventional resin cement.

광원에 따른 중합광의 복합레진 중합 능력 비교

신혜진,김진우,조경모 大韓齒科保存學會 2003 Restorative Dentistry & Endodontics Vol.28 No.2

The purpose of this study is to evaluate the polymerization ability of three different light sources by microhardness test. Stainless steel molds of 1, 2, 3, 4 and 5 mm in thickness of 7 mm in diameter were prepared. The hybrid composite Z100 was packed into the hole of the mold and curing light was activated for designated time. Three different light sources, conventional halogen, light emitting diode, and plasma arc, were used for curing of composite. Two different curing times applied; one is to follow the manufacturers recommendation and the other is to extend the curing time of LED and plasma arc for balancing the light energy with halogen. Immediately after curing, the Vickers hardness was measured at the bottom of specimen. The results were as follows. 1. The composite cured with LED showed equal to higher microhardness than halogen. 2. The composite was cured with plasma arc by manufacturers recommendation showed lowest microhardness at all thickness. However, when curing time was extended, microhardness was higher than the others. In conclusion, this study suggested that plasma arc needs properly extended curing time.

세계화ㆍ지식기반사회에 대한 중등학교 사회과 교사들의 경제의식 및 의견 분석

최병모,김진영,조병철,안상환 한국경제교육학회 2004 경제교육연구 Vol.11 No.1

리본형태의 근관에서의 열연화 근관 충전법의 비교 : 근관 충전된 gutta-percha의 무게 WEIGHT OF FILLED GUTTA-PERCHA

김현희,조경모,김진우 大韓齒科保存學會 2002 Restorative Dentistry & Endodontics Vol.27 No.3

The purpose of this study is to evaluate the two warm gutta-percha filling techniques by measuring the weight changes of resin blocks before and after canal filling in ribbon shaped canal. Simulated ribbon shaped root canals in 30 transparent resin blocks were instrumented to #40 using .06 taper Profile. 16 resin blocks were obturated with gutta-percha using cold lateral condensation. Warm lateral condensation using the Endotec Ⅱ was then accomplished on the same 15 blocks. Another 15 resin blocks were obturated using the System B. All canals were obturated without sealer. The resin blocks were weighed after canal preparation and after each subsequent obturation, and then weight changes of the resin blocks were calculated. The results were as follows. 1. Warm lateral condensation using Endotec Ⅱ and continuous wave of condensation using System B produced a denser obturation of gutta-percha compared with conventional cold lateral condensation (p<0.01). 2. There was no significant difference between warm lateral condensation and continuous wave condensation. In conclusion, the warm gutta-percha condensation techniques like warm lateral condensation and continuous wave condensation can be expected to bring favorable canal obturation results in ribbon shaped canals.

리본 형태의 근관에서 열연화주입법의 근관벽에 대한 적합도에 관한 연구 : ADAPTATION TO CANAL WALLS

황현숙,조경모,김진우 大韓齒科保存學會 2002 Restorative Dentistry & Endodontics Vol.27 No.4

The aim of this study is to compare the adaptability of thermoplasticized injectable gutta-percha technique to the canal walls in ribbon-shaped canals. Thirty resin models simulated ribbon-shape canals were instrumented to #40 using. 06 taper Profile systems. Three groups of each 10 resin models were obturated by the lateral condensation technique(LC) and the two thermoplasticized injectable gutta-percha technique; Ultrafil Endoset+Obtura Ⅱ(EO) and Ultrafil Firmset(UF), respectively. After resin model were kept at room temperature for 4 days, they were resected horizontally with microtome at 1, 2, 3, 4 and 5mm levels from apex. At each levels, image of resected surface were taken using CCD camera under a stereomicroscope at ×40 magnification and stored. Ratio of the area of gutta-percha was obtained by calculating area of gutta-percha cone to the total area of canal using digitized image-analyzing program. The data were collected then analyzed statistically using One-way ANOVA. The results were as follows. 1. At 1mm levels, there was no statistically significant difference in the mean ratio gutta-percha among the groups. 2. At 2mm level, EO showed the highest mean ratio of gutta-percha (p<0.05) and there was no significant difference between LC and UF. 3. At 3, 4, 5mm levels, EO and UF and had significantly greater mean ratio of gutta-percha than LC(p<0.05) and there was no significant difference between EO and UF. In conclusion, the thermoplasticized injectable gutta-percha techniques demonstrated relatively favorable adaptability to canal walls than lateral condensation technique in ribbon-shaped canals except for 1mm level.

K3에 축적된 내부 응력이 피로 파절에 미치는 영향

김준영,김진우,조경모,박세희 大韓齒科保存學會 2012 Restorative Dentistry & Endodontics Vol.37 No.2

Objectives: This study aimed to evaluate the relationship between the cyclic fatigue of a K3 file and internal stress intentionally induced until the activation of the auto-stop function of the torque-controlled motor. Materials and Methods: K3 (Sybron Endo) .04 and .06 taper, size 25, 30, 35, 40 and 45 were used in this study. To give the internal stress, the K3 files were put into the .02 taper Endo-Training-Bloc (Dentsply Maillefer until the activation of the auto-stop function of the torque-controlled motor. The rotation speed was 300 rpm and torque value was 1.0 N·cm. K3 were grouped by the number of induced internal stress and randomly distributed to 4 experimental groups (n = 10, Stress 0 [control], Stress 1, Stress 2 and Stress 3). For measuring the cyclic fatigue failure, the K3 files were worked against a sloped glass block and time for file separation was recorded. Data was statistically analyzed Statistical analyses were performed using two-way ANOVA and Duncan post-hoc test at p < 0.05 level. Results: Except .04 taper size 30 in Stress 1 group, there were statistically significant differences in time for file separation between control and all experimental groups. K3 with .04 taper showed higher cyclic fatigue resistance than those of .06 taper. Conclusion: In the limitation of this study, the cyclic fatigue of the K3 file was influenced by the accumulated internal stress from use until the auto-stop function was activated by the torque-controlled motor. Therefore, clinicians should avoid the reuse of the K3 file that has undergone auto-stops. (Restor Dent Endod 2012;37(2):74-78)

내부 응력이 .06 taper Profile의 피로 파절에 미치는 영향

정혜림,김진우,조경모,박세희 大韓齒科保存學會 2012 Restorative Dentistry & Endodontics Vol.37 No.2

Objectives: The purpose of this study was to evaluatie the reation between intentionally induced internal stress and cyclic fatigue failure of .06 taper ProFile. Materials and Methods: Length 25 mm, .06 taper ProFile (Dentsply Maillefer), and size 20, 25, 30, 35, and 40 were used in this study. to give the internal stress, the rotary NiTi files were put into the .02 taper, Endo-Training Bloc (Dentsply Maillefer) until auto-stop by torque controlled motor. Rotary NiTi files were grouped by the number of induced internal stress and randomly distributed among one control group and three experimental groups (n = 10, Stress 0 [control], Stress 1, Stress 2 and Stress 3). For cyclic fatigue measurement, time for separation of the rotary NiTi files was recorded. the fractured surfaces were observed by field emission scanning electron microscope (FE-SEM, SU-70, Hitachi). The tiem for separation was statistically analyzed using two-way ANOVA and post-hoc Scheffe test at 95% level. Results: In .06 taper ProFile size 20, 25, 30, 35, and 40, there were statistically significant difference on time for separation between control group and the other groups (p < 0.05). Conclustion: In the limitation of this study, cyclic fatigue failure of .06 taper ProFile is influenced by internal stress accumulated in the files. (Restor Dent Endod 2012;37(2):79-83)