• Restorative Dentistry and Endodontics
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• 제29권5호
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• pp.439-445
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• 2004

Continuous Wave 가압법으로 근관충전시 플러거 삽입 깊이에 따른 근관실러의 치근단 정출을 평가하고자 직선형의 단근관 및 15번 크기의 치근단공을 가지는 발거된 40개의 치아에서 0.06 경사도 40번 크기가 되게 니켈-티타늄 전동화일인 $ProFile^{\circledR}$로 근관을 형성하고 플러거 삽입깊이를 근단 3, 5 또는 7 mm로 하여 System $B^{TM}$를 이용한 Continuous Wave 가압법 및 측방가압법으로 근관을 충전하였다. 치근단으로 정출된 근관실러의 무게를 측정하여 일원변량분석법과 Duncan's Multiple Range Test로 통계분석하였다. 플러거 삽입깊이 3 mm 또는 5 mm의 Continuous Wave 가압 충전군은 삽입깊이 7 mm 가압충전 군 및 측방가압 충전군에 비해 유의하게 많은 근관실러의 치근단 정출을 나타내었다 (p < 0.05). 그러나 플러거 삽입깊이 3 mm군과 5 mm군 사이 및 플러거 삽입깊이 7 mm Continuous Wave 가압군과 측방가압 군 사이에는 유의한 차이가 나타나지 않았다 (p > 0.05). 본 연구의 결과로 보아 Continuous Wave 가압법으로 근관충전시에는 플러거 삽입깊이가 깊을수록 근관실러의 치근단 정출이 많음을 알 수 있다.

• Restorative Dentistry and Endodontics
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• 제24권3호
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• pp.490-494
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• 1999

The aim of this in vitro study was to investigate the coronal leakage of obligate anaerobes into root canals obturated with two different techniques. 48 extracted human teeth with straight, single root canals were prepared with crown-down technique with Profile under copious irrigation until the master apical file was size 40. The teeth were divided randomly into experimental groups (40 teeth) and control groups (8 teeth). In the experimental groups, 20 teeth were obturated with lateral condensation and other 20 teeth were obturated with continuous wave technique with System B. Coronal leakage of two root canal filing technique was evaluated using anaerobic bacterial leakage model with Fusobacterium nucleatum(ATCC 25586) for 60 days. The results were as follows 1. The incidence of bacterial leakage of experimental groups was 65% in group 1 (lateral condensation) and 60% in group 2 (continuous wave technique with System B). This difference was not statistically significant (P>0.05). 2. There was no statistically significant difference(P>0.05) in leakage score between group 1 (lateral condensation) and group2 (continuous wave technique with System B).

• Restorative Dentistry and Endodontics
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• 제23권1호
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• pp.346-356
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• 1998

The purpose of this study was to evaluate the sealing ability of various canal filling methods. Palatal roots of ninety extracted human maxillary molar teeth were resected at cementoenamel junction. Eighty of them were randomly assigned to four experimental groups, ten were served as positive and negative controls. All canals were prepared to # 40 using Profile. Experimental groups were obturated by lateral condensation technique, Thermafil technique, Continuous Wave of Condensation Technique, and down-pack & back-fill technique of Obtura-II, each with root canal sealer. Control groups were not obturated. Teeth were immersed in resorcinol-formaldehyde resin for 5 days at $4^{\circ}C$, and the resin was allowed to polymerize completely for 4 days at room temperature. Teeth were then ground horizontally at 1.5mm(level 1), 2.5mm(level 2), 3.5 mm(level 3) from the anatomical apex and examined with a stereomicroscope at ${\times}40$ magnification. The gap between the canal wall and the filling material, which was filled with the resin, was measured at each of the three levels. Each ratio of leakage was obtained by calculating the ratio of the area of the resin to the total area of the canal and was analyzed statistically (Rank-sum test). The results were as follows : 1. At the level 1, there was the greatest leakage in the Thermafil group and Obtura-II group, and the difference between the Obtura-II group and Continuous Wave of Condensation Technique group was statistically significant(p<0.05). 2. At the level 2, there was the least leakage in the Continuous Wave of Condensation Technique group, but there was no statistically significant difference between each group (p>0.05). 3. At the level 3, there was no statistically significant difference between each group(p>0.05).

• Restorative Dentistry and Endodontics
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• 제28권4호
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• pp.341-347
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• 2003

This study was conducted to evaluate the temperature rise on the root surface while the root canal is being obturated using continuous wave of condensation technique. Maxillary central incisor was prepared for repeated canal obturation. Ten thermocouples (Omega Engineering Inc., Stanford, USA) were placed at 1 mm increment from the anatomical root apex. The real temperature of Buchanan plugger was recorded before insertion into the root canal. The root canal was obturated with continuous wave of condensation technique as described by Buchanan and the root surface temperature was recorded during obturation at $150^{\circ}C,{\;}200^{\circ}C,{\;}250^{\circ}C{\;}and{\;}300^{\circ}C$ temperature settings of System B HeatSource (Model 1005, Analytic technologies, Redmond, WA, USA). After completion of the temperature recording, the dentinal-cementum thickness at each sites was measured. The data were analyzed using one-way ANOVA followed by Scheffe's test and linear regression test. The results were as follows. 1. When the temperature was set at $150^{\circ}C,{\;}200^{\circ}C,{\;}250^{\circ}C{\;}and{\;}300^{\circ}C$ on the digital display of System B HeatSource, the real temperature of the plugger at the 1mm point from the tip revealed $130.82{\pm}2.96^{\circ}C,{\;}158.00{\pm}5.26^{\circ}C,{\;}215.92{\pm}6.91^{\circ}C{\;}and{\;}249.88{\pm}3.65^{\circ}C$ respectively. 2. The position of 8 mm from the anatomical apex showed the highest temperature increase at each temperature settings and it was significantly higher than those of other positions (p<0.0l). The temperature rise was constantly increased toward coronal portion from apex of the root. 3. The maximum temperature increase on the root surface was $2.37{\pm}0.09^{\circ}C{\;}at{\;}150^{\circ}C{\;}setting,{\;}3.11{\pm}0.12^{\circ}C{\;}at{\;}200^{\circ}{\;}setting,{\;}3.93{\pm}0.09^{\circ}C{\;}at{\;}250^{\circ}C{\;}setting{\;}and{\;}5.69{\pm}0.15^{\circ}C{\;}at{\;}300^{\circ}C$ setting respectively. These results suggest that it be relatively kind to the supporting tissues of the root that the root canal is obturated using continuous wave of condensation technique at $150^{\circ}C,{\;}200^{\circ}C,{\;}250^{\circ}C{\;}and{\;}300^{\circ}C$ temperature settings on digital temperature display of System B HeatSource.

• Restorative Dentistry and Endodontics
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• 제32권6호
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• pp.491-497
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• 2007

이 연구의 목적은 continuous wave of obturation technique으로 근관 충전을 할 때, 다양한 heat source plugger의 깊이에 따른 근단부 근관 폐쇄능력을 비교하는 것이었다. 직선 형태 발거 소구치를 #35/.06 크기까지 니켈티타늄 파일을 사용하여 성형 및 세정하였다. 성형과 세정이 완료된 치아를 heat source plugger의 적용 깊이에 따라 15개씩 5군으로 분류하였다. 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 양성 대조군을 제외한 모든 근관은 E&Q plus(Meta Biomed Co., Chungju, Korea)를 사용하여 #35/.06 gutta-percha cone으로 충전하였다. 모든 치아의 근첨공 주변 1 mm를 제외하고 nail varnish를 도포하였고 음성 대조군은 근첨공을 포함하여 전체 면을 도포하였다. 모든 시편을 1% 메틸렌블루 용액에 72시간 동안 보관한 다음 치근첨으로부터 1, 2, 3 mm 높이에서 수평으로 절단하였다. 각 단면을 $12.5{\times}2.5$배 현미경하에서 관찰하고 디지털 카메라로 촬영하였다. 염색제 누출 평가를 위해 aye-degree scoring system을 사용하였다. 각 절단면에서의 점수를 모두 합하여 한 시편의 점수로 사용하고 통계학적 분석을 하였다. 이 실험 조건하에서, 3-7 mm까지의 heat source plugger의 적용 깊이는 근단부 폐쇄에서 유의한 차이를 나타내지 않았다. 5-7 mm의 Buchanan's protocol을 포함한 3-7 mm를 모두 임상 적용에서 받아들여질 만하다고 보인다.

• 한국지구과학회지
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• 제28권7호
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• pp.903-913
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• 2007

천부지반에서 레일리파의 군속도와 위상속도 분산곡선을 역산하여 S파 속도구조를 구하는 방법을 비교하였다. 위상속도를 구하기 위해서 ${\tau}-p$ stacking 방법을 이용하였고, 군속도를 구하기 위해서 두 가지 방법, multiple filtering technique(MFT) continuous wavelet transform(CWT) 방법을 사용하였다. 고차모드가 존재하는 경우, 위상속도에서 기본모드와 고차모드를 분리하기가 용이하지 않았고, 군속도에서는 continuous wavelet transform 방법이 multiple filtering technique보다 효과적이었다. S파 속도 역산 결과, 위상속도와 군속도의 기본 모드만 역산할 경우, 신뢰구간의 깊이가 아주 얕았다. Continuous wavelet transform으로 구한 기본 모드와 1차 모드를 동시 역산할 경우, 신뢰구간의 깊이가 2배 이상 증가함을 알 수 있었다. 이는 1차 모드의 에너지가 더 깊은 층을 통과함으로 깊은 층에 대한 5파 속도 정보를 지니고 있기 때문으로 보인다. 위의 방법을 서해안 동호항의 조간대에 적용하여, continuous wavelet transform으로 구한 군속도의 기본 모드와 1차 모드를 동시 역산하여 S파 속도구조를 구하고, 해당 지역의 시추조사 결과와 비교하였다.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2006년도 정기 학술대회 논문집
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• pp.97-103
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• 2006

A modified one-sided measurement technique is proposed for Rayleigh wave (R-wave) velocity measurement in concrete. The scattering from heterogeneity may affect the waveforms of R-waves in concrete, which may make the R-waves dispersive. Conventional one-sided techniques do not consider the scattering dispersion of R-waves in concrete. In this study, the maximum energy arrival concept is adopted to determine the wave velocity by employing its continuous wavelet transform. Experimental study was performed to show the effectiveness of the proposed method. The present method is applied to monitor the strength development of early-age concrete. A series of experiments were performed on early-age concrete specimens with various curing conditions. Results reveal that the proposed method can be effectively used to measure the R-wave velocity in concrete structures and to monitor the strength development of early-age concrete.

• 한국소음진동공학회논문집
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• 제20권3호
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• pp.272-278
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• 2010

A method for damage detection in a plate structure is presented based on strain waves that are generated by impact or damage in the structure. Strain responses from continuous sensors, which are long ribbon-like sensors made from piezoceramic fibers or other materials, were used with a neural network technique to estimate the damage location. The continuous sensor uses only a small number of channels of data acquisition and can cover large areas of the structure. A grid type structural neural system composed of the continuous sensors was developed for effective damage localization in a plate structure. The ratios of maximum strains and arrival times of the maximum strains obtained from the continuous sensors were used as input data to a neural network. Simulated damage localizations on a plate were carried out and the identified damage locations agreed reasonably well with the exact damage locations.

• Restorative Dentistry and Endodontics
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• 제33권6호
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• pp.518-525
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• 2008

본 연구의 목적은 제 IV형 근관에서 Continuous Wave 가압법을 이용하여 충전할 때 System B Plugger tip의 깊이에 따른 근단부 밀폐효과를 평가하기 위함이다. 50개의 J형 만곡을 갖는 레진 블록에 부러진 F3 ProTaper 파일을 이용해 근관장에서 3mm 지점에 ledge를 형성한 후, F1 ProTaper Ni-Ti file을 이용해 레진 블록을 천공시켜 제 IV형 근관을 형성하고 System B Plugger tip의 깊이에 따라 3개의 실험군과 1개의 대조군으로 분류하였다. 제 IV형 근관의 거터퍼쳐와 실러의 길이는 확대경하에서 캘리퍼를 이용해 측정하였고 다음과 같은 결과를 얻었다. 1. 대조군의 설측 근관에서 거터퍼쳐와 실러 모두 관찰되지 않았다. 2. 3 mm군에서는 5 mm 또는 7 mm군에 비해 유의하게 많은 거터퍼쳐의 충전이 관찰되었다 (p<0.05). 3. 7 mm군에서는 유의하게 많은 빈 공간이 관찰되었다 (p<0.05).

• Restorative Dentistry and Endodontics
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• 제31권1호
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• pp.66-71
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• 2006

Continuous Wave 가압법으로 근관충전시 plugger 삽입 깊이에 따른 근관내 gutta-percha 비율을 평가하고자 40개의 발거치아 근관을 0.06 경사도 40번 크기의 $ProFile^{(R)}$로 근관을 형성하고 세 군에서는 plugger 삽입깊이를 근단 3, 5 또는 7 mm로 하여 System $B^{TM}$를 이용하여 Continuous Wave 가압법으로 충전하였고, 한 군에서는 대조군으로서 측방가압법으로 근관을 충전하였다. 충전된 근관은 치근단 1, 2 및 3mm 수준에서 횡절단하여 근관내 gutta-percha 면적비를 계산하고 일원변량분석법을 이용하여 통계분석 하였다. 모든 절단수준에서, Continuous Wave 가압법으로 충전한 군 사이에서는 plugger의 삽입깊이가 깊을수록 높은 gut-ta-percha 면적비를 나타내었고, 측방가압법으로 충전한 군이 plugger의 삽입깊이를 7 mm로 충전한 군보다 높은 gut-ta-percha 면적비를 나타내었다 (p<0.05).