프리캐스트 포스트텐션 콘크리트 넓은 보-기둥 내부 접합부의 비탄성 거동

황재환,최윤철,김영찬,김대중,임재형,권기혁,문정호,이리형 대한건축학회 2003 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.23 No.2(구조계)

The purpose of this paper is to evaluate the response of Precast Prestressed Concrete Interior Wide Beam-Column Joint subjected to cyclic lateral loading. To this end, the experimental investigation was performed with six half-scale specimens of interior connection. The design parameters are the beam to column depth ratio, and the number of tendons within column core. One of the specimens, IJH-6, is modeled for the connection at the top floor of a structure. The test results showed that the specimens sufficiently resist up to limiting drift ratio of 0.035 in accordance with the provisional standard by ACI of acceptance criteria for concrete special moment frames.

수종의 역충전 재료의 치근단 밀폐력 비교

황윤찬,강인철,황인남,오원만 대한치과보존학회 2001 Restorative Dentistry & Endodontics Vol.26 No.5

This study was performed to evaluate the sealing ability of various retrograde filing materials by using bacterial penetration and dye penetration test. One hundred and forty extracted human teeth with single, straight canals and mature apices were collected and used for this study. All canals were instrumented using an engine driven Ni-Ti file (ProFile). After removing 3mm from the apex of tooth, a standardized 3mm root end cavity was prepared using an ultrasonic instrument. The 70 teeth were randomly divided into 7 groups : 6 groups for retrograde filling using Super-EBA, ZOE, Chelon-Silver, IRM, ZPC and amalgam. The 7th group was used as a negative control. Nail varnish was applied to all external root surfaces to the level of the resected root ends to prevent lateral microleakages. The specimens were then sterilized in an ethylene oxide sterilizer for 24 hours. 2 mm of the rejected root was immersed in a culture chamber containing a Tripticase Soy Broth with a phenol red indicator. The coronal access of each specimen was inoculated every 72 hours with suspension of Proteus vulgaris. The culture media were observed every 24hours for color change indicating bacterial contamination. The specimens were observed for 4weeks. The remaining 70 teeth were submitted to a dye penetration test. The canals of all teeth were first sealed with AH26 and obturated using an Obtura II system. Root resection, root end preparation and retrograde filling was performed as above. All specimens were suspended in 2% methylene blue dye for 72 hours before being longitudinally split. The degree of dye penetration was then measured using a stereomicroscope at 10 magnification and evaluated. The results were as follows : 1.In the bacterial penetration, the degree of leakage was the lowest in the Super-EBA, followed by, in ascending order, ZOE, Chelon-Silver IRM and ZPC. The amalgam showed highest bacterial leakage of all(p<0.01) . 2.In the dye penetration, the degree of microleakage was the lowest in the Chelon-Silver and Super-EBA, followed by, in ascending order, IRM, ZPC. The ZOE and amalgam showed the highest microleakage of all(p<0.05) . These results suggested that the eugenol based cement, Super-EBA, have excellent sealing ability as a retrograde filling material.

Cs이 흡착된 Si(111)7×7 표면의 초기 산화과정 연구

황찬국,안기석,이득진,장현덕,박종윤 성균관대학교 기초과학연구소 1995 論文集 Vol.46 No.1

X-ray photoelectron spectroscopy를 이용하여 상온에서 Cs이 1ML 흡착된 Si(111)7 × 7 표면의 초기 산화과정에 대하여 연구하였다. 산소의 주입량과 Cs의 흡착량의 변화에 따른 0 1s, Cs 3d_(5/2), 그리고 Si 2p 스펙트럼의 변화를 관측하였다. 이러한 측정결과, 표면에 흡착되는 산소량은 Cs의 임계피복량(약 0.5ML)이상에서 급격한 증가를 보임을 알 수 있다. 따라서 Si(111) 7 × 7-Cs 표면의 산화과정은 non-local mechanism을 따르는 것으로 이해할 수 있다. 또한 0 1s 스펙트럼에 서로 다른 chemical environment를 가진 두 종류의 산소 성분이 존재하는 것을 알수 있다. 이러한 두 종류의 0 1s 성분중 높은 운동에너지 성분의 세기는 Cs 흡착량에 의존하며 낮은 운동에너지 성분은 Cs이 완전히 탈착된 후에도 남아있다. 그리고 산소 주입량이 증가함에 따라 Si 2p peak의 세기는 감소하는 반면 Cs 3d_(5/2) peak의 세기는 거의 일정하다. 이러한 결과로부터 Si(111) 7 × 7 표면에 주입되는 산소원자는 Si-0-Si, Si-0-Cs 두 종류의 결합형태를 가지는 것으로 예상된다. We have studied initial oxidation of Cs-adsorbed Si(111)7×7 surface using X-ray photoelectron spectroscopy at room temperature. It was measured that the changes of 0 1s, Cs 3d_(5/2) and Si 2p spectrum with increasing O_2 exposure and Cs deposition time, respectively. The 0 1s/Si 2p peak intensity ratio rapidly increased at 0.5ML Cs coverage, which means that the non-local mechanism is favored on the Cs-promoted oxidation. The 0 1s peak observed consists of two chemical-shifted components. The 0 1s peak intensity of high kinetic energy component depended on the Cs coverage while low kinetic energy component still remained after complete Cs desorption. The Cs 3d_(5/2) peak intensity was nearly constant, though the Si 2p peak intensity decreased with increasing O_2 exposure. These results suggest that oxygen atoms adsorbed on the Si(111)7×7 surface have two different bond configurations such as Si-O-Si, Si-O-Cs.

치과용 심미 수복 재료들의 색상 연구를 통한 새로운 치과용 색체계의 제안

오윤정,박수정,김동준,조현구,황윤찬,오원만,황인남 대한치과보존학회 2007 Restorative Dentistry & Endodontics Vol.32 No.1

본 연구는 새로운 치과용 색체계 개발을 목적으로 현재 치과에서 사용되고 있는 Vita shade를 사용하는 9 제조사의 12종의 광중합형 복합레진과 1종의 치과용 도재의 색상을 diffuse/8° 수광 방식을 사용하는 분광색체계 (MiniScan XE plus, Model 4000S, Hunter Lab, USA)를 이용해 D65 표준광과 10도 관찰자 시야 하에서 CIE L^(*)a^(*)b^(*) 값을 측정하고 색상 범위를 분석하였다. 분석한 정보를 color sorting system을 응용한 CNU Cons Dental Color Chart의 색상 표현 방식인 T###에 치과용 수복 재료들의 범위를 적용하여 다음의 결과를 얻었다. 측정된 L^(*)a^(*)b^(*)값의 분포를 분석해 보면 L^(*)값은 80.40과 52.70 사이에, a^(*)값은 10.60과-3.60 사이에, 그리고 b^(*)값은 28.40과 2.21 사이에 분포한다. L^(*)값의 평균값은 67.40, 중앙값은 67.30이며, a^(*)값은 2.89와 2.91, b^(*)값은 14.30 과 13.90 이다. 이러한 분석을 토대로 CNU Cons Dental Color Chart의 T###의 첫 번째 숫자에 해당하는 L^(*)값의 각 숫자간의 차이는 2.0으로, 그리고 2번째 숫자인 a^(*)값의 각 숫자간의 차이는 1, 그리고 세 번째 숫자인 b^(*)값의 각 숫자간의 차이는 2로 정하였다. T555에 해당하는 L^(*)값의 범위는 66.0이상, 68.0미만으로, a^(*)값의 범위는 3이상 4미만으로, b^(*)값의 범위는 14이상 16미만으로 결정하였다. The purpose of this study is to develope new dental color-space system. Twelve kinds of dental composites and one kind of dental porcelain were used in this study. Disk samples (15 ㎜ in diameter, 4 ㎜ in thickness) of used materials were made and sample’s CIE L^(*)a^(*)b^(*) value was measured by Spectrocolorimeter (MiniScan XE plus, Model 4000S, diffuse/8° viewing mode, 14.3 ㎜ Port diameters, Hunter Lab. USA). The range of measured color distribution was analyzed. All the data were applied in the form of T### which is expression unit in CNU Cons Dental Color Chart. The value of L^(*) lies between 80.40 and 52.70. The value of a^(*) are between 10.60 and 3.60 and b^(*) are between 28.40 and 2.21. The average value of L^(*) is 67.40, and median value is 67.30. The value of a^(*) are 2.89 and 2.91 respectively. And for the b^(*), 14.30 and 13.90 were obtained. The data were converted to T### that is the unit count system in CNU-Cons Dental Color Chart. The value of L^(*) is converted in the first digit of the numbering system. Each unit is 2.0 measured values. The second digit is the value of a^(*) and is converted new number by 1.0 measured value. For the third digit b^(*) is replaced and it is 2.0 measured unit apart. T555 was set to the value of L^(*) ranging from 66.0 to 68.0, value of a^(*) ranging from 3 to 4 and b^(*) value ranging from 14 to 16.

상아세관의 주행방향에 따른 상아질 접착제의 침투양상에 대한 공초점레이저주사현미경 연구

김동준,황윤찬,김선호,오원만,황인남 大韓齒科保存學會 2003 Restorative Dentistry & Endodontics Vol.28 No.5

The purpose of this study was to evaluate the penetration pattern of dentin adhesives according to the orientation of dentinal tubules with confocal laser scanning microscopy. Specimens having perpendicular. parallel and oblique surface to dentinal tubules were fabricated. The primer of dentin adhesives (ALL BOND 2, CLEARFIL SE BOND and PQ1) was mixed with fluorescent material. rhodamine B isothio cyanate (Aldrich Cherm. CO., Milw., USA), It was applied to the specimens according to the instructions of manufactures. The specimens were covered with composite resin (Estelite, shade A2) and then cut to a thickness of 500 ㎛ with low speed saw (Isomet, Buehler, USA). The adhesive pattern of dentin adhesives were observed by fluorescence image using confocal laser scanning microscopy. The results were as follows. 1. For the groups with tubules perpendicular to bonded surface, funnel shape of resin tag was observed in all specimen. However. resin tags were more prominent in phosphoric acid etching system (ALL BOND 2 and PQ1) than self etching system (CLEARFIL SE BOND). 2. For the groups with tubules parallel to bonded surface. rhodamine labeled primer penetrated into peritubular dentin parallel to the orientation of dentinal tubules. But rhodamine labeled primer of PQ1 diffused more radially into surrounding intertubular dentin than other dentin adhesive systems. 3. For the groups with tubules oblique to bonded surface. resin tags appeared irregular and discontinuous. But they penetrated deeper into dentinal tubules than other groups.

근관 세척법이 Resilon/Epiphany sealer와 Gutta-percha/AH 26 sealer의 근관 상아질과의 접착에 미치는 영향

김서경,황윤찬,황인남,오원만 大韓齒科保存學會 2008 Restorative Dentistry & Endodontics Vol.33 No.2

본 연구에서는 근관 세척법이 두 가지 근관 충전재 (Gutta-percha/AH 26 sealer, Resilon/Epiphany sealer)의 근관 상아질과의 접착메 미치는 영향을 평가하였다. 총 30개의 발거된 상악 전치를 각자 5개씩 6개의 군으로 분류하여 근관 성형을 하고 마지막 세척을 다음과 같이 시행 한 후 Gl, G2, G3군은 Gutta-percha/AH 26 sealer로, Rl, R2, R3군은 Resilon/Epiphany sealer로 근관 충전하였다. Gl, Rl군 : 5.25% NaOCl세척 G2, R2군 : 5.25% NaOCl세척 후 sterile saline 세척 G3, R3군 : 5.25% NaOCl세척 후 17% EDTA, sterile saline 순으로 세척 각 군의 충전된 치아를 아크릴 레진에 매몰하고 약 1 mm 두께로 절단한 후 만능 물성 시험기상에서 push-out bond strength를 측정하였고 실험 후 파절 양상을 Image-analyzing microscope으로 관찰하여 다음과 같을 결과를 얻었다. 1. Gutta-percha/AH 26 sealer 충전군에서 Resilon/Epiphany sealer 충전군보다 push-out bond strength가 높게 나타났다 (p < 0.05). 2. Resilon/Epiphany sealer 충전군 중 17% EDTA, sterile saline순으로 세척시 5.25% NaOCl 세척에 비해 push-out bond strength가 높게 나타났다 (p<0.05). 3.파절 양상을 분석시 모든 군은 접착성과 혼합성 파절 양상을 나타내었고, Gl, G2, Rl 군은 응집성 파절 양상이 나타나지 않았으며, Resilon/Epiphany sealer 충전군은 Gutta-percha/AH 26 sealer 충전군에 비해 응집성과 혼합성 파절 망상이 더 높은 비율로 나타났다. The purpose of this study was to evaluate whether intracanal irrigation method could affect the adhesion between intracanal dentin and root canal filling materials (Gutta-percha/AH 26 sealer and Resilon/Epiphany sealer). Thirty extracted human incisor teeth were prepared. Canals were irrigated with three different irrigation methods as a final rinse and obturated with two different canal filling materials (G groups : Gutta-percha/AH 26 sealer, R groups : Resilon/Epiphany sealer) respectively. Group Gl, Rl - irrigated with 5.25% NaOCl Group G2, R2 - irrigated with 5.25% NaOCl, sterile saline Group G3, R3 - irrigated with 5.25% NaOCl, 17% EDTA, stehle saline Thirty obturated roots were horizontally sliced and push-out bond strength test was performed in the universal testing machine. After test, the failure patterns of the specimens were observed using Image-analyzing microscope. The results were as follows. 1. Gutta-percha/AH 26 sealer groups had significantly higher push-out bond strength compared with the Resilon/Epiphany sealer groups (p < 0.05). 2. Push-out bond strength was higher when using 17% EDTA followed by sterile saline than using NaOCl as a final irrigation solution in the Resilon/Epiphany sealer groups (p < 0.05). 3. In the failure pattern analysis, there was no cohesive failure in Group Gl, G2, and Rl. Gutta-percha/AH 26 sealer groups appeared to exhibit predominantly adhesive and mixed failure patterns, whereas Resilon/Epiphany sealer groups exhibited mixed failures with the cohesive failure occurred within the Resilon substrate.

머리염색이 인체에 미치는 영향

윤형식,황성호,이현륭,김수호,박연석,권낙현,정호진,김동훈,노현주,홍성호,박병찬,이관,정해관 東國大學校醫學硏究所 2002 東國醫學 Vol.9 No.1

일상생활에서 모발염색은 흔히 접할 수 있는 미용의 한 종류로 특히 젊은층을 중심으로 폭발적으로 유행하고 있다. 염색을 위항 사용하는 약제는 표백제와 발색제 등 각종 화학약품이 사용되고 있으나 이로 인한 건강장해에 대한 연구는 그리 많지 않다. 저자들은 염색이 인체의 모발건강에 미치는 영향을 파악하기 위하여 염색과 관련된 주관적 증상과 모발의 변화에 대한 실험적 연구를 시행하였다. 동국대학교 경주 캠퍼스 재학생 80명을 대상으로 설문조사를 시행하여 염색 유 ·무 및 염색 후에 경험한 증상에 대해 설문 조사하였고, 의과대학 재학생 46명을 대상으로 피부 반응 테스트를 실시하였다. 또한 염색 전후의 모발 탄성도를 측정하였고 모발의 상태를 파악하기 위해 전자 현미경검사를 실시하였다. 설문조사 결과 염색 전에 비하여 염색 후 안구혼탁, 안구건조, 시력저하, 발진 및 접촉성 피부염, 모발손상, 모근손상 등의 증상을 더 많이 경험한다고 호소하였다(p<0.05). 모발손상과 모근손상은 헤어드라이어 사용 빈도에 따라 증가하는 것으로 조사되었다(p<0.05). 피부반응검사에서 가려움증이 가장 많은 증상이었으며 이는 여성보다는 남성에서 높은 것으로 조사되었다. 염색 전후의 모발장력은 염색 전 134.5±10.37g, 염색 128.0±30.69g, 염색 이틀 후 112.5±19.69g으로 나타났다. 염색 전후의 모발의 전자현미경 케라틴 층이 현저히 감소하고 모발이 가늘어지는 차이를 보였다. 염색은 모발손상, 모발 케라틴 손상 및 모근 손상, 발진 및 접촉성 피부반응, 안구혼탁, 안구건조, 시력 저하를 유발한다. 따라서 염색약으로 인한 손상에 대한 주의와 예방이 필요하다고 생각한다. 예방대책으로 염색 전 피부테스트를 통한 적합성 여부를 판단하는 것이 필요하며 가급적 염색을 피하는 것이 좋을 것이다. 염색약에 발암물질이 포함되어있다는 보고도 있어 염색 제조사의 철저한 실험과 염색 물질의 선별이 염색으로 인한 부작용을 최소화하는데 중요한 역할을 할 것이다. Hair coloring has became one of the most popular cosmetic activities to younger generations during last decade. However, there are few studies on the health effect of widespread use of chemical dyes. This study was conducted to study the effects of hair coloring dye on hair and other systems. We conducted a questionnaire survey of 80 persons in Kyongju campus, Dongguk University. We have done open patch skin test on 46 medical students. We also conducted scanning electron microscopy to examine the hair strength and structure before and after hair coloring process. Injury of hair and hair bulb, contact dermatitis, turbid eyes, xerophthalmia, and poor visual acuity were the main symptoms complained after hair coloring (p<0.05). Injury of hair and hair bulb were increased by frequency of hair-dryer use(p<0.05). In open patch test, pruritus was complanined by more than half of the subjects. Mean strength of hairs before and after hair coloring was as follows; 134.5 (SD 10.37)g before hair coloring, 128.0 (SD 30.69)g immediately after hair coloring, and 112.5 (SD 19.69)g after two days. The scanning electron microscopic findings of hair surface before and after hair coloring showed decreased keratin layer and thinning of the hair. Hair coloring induces injury to hair, its keratin layer, and hair bulb as well as contact dermatitis, turbid eyes, xerophthalmia, and poor visual acuity. Therefore, we think that precaution is needed in use of hair coloring dye. To prevent complications induced by hair coloring dye, it is necessary, especially to those with allergy or skin disorders, to perform skin test before action and avoid hair coloring whenever possible. Longterm health effects of hairdye should be studied and manufacturing companies should try to minimize complications induced by hair coloring dye.

열전대(thermocouple)를 이용한 Buchanan Plugger 표면의 온도상승 분석

조진숙,황윤찬,김선호,황인남,최보영,정영진,정우남,오원만 大韓齒科保存學會 2003 Restorative Dentistry & Endodontics Vol.28 No.4

This study was performed to evaluate the actual temperature rise on the surface of Buchanan plugger using thermocouple. The heat carrier system 'System B Heatsource'(Model 1005, Analytic Technologies, Redmond, WA, USA) and the Buchanan pluggers of F, FM, M and ML sizes are used for this study. The temperature was set to 200℃ on digital display and the power level on it was set to 10. Five thermocouples were placed in direct contact with the surface of each size of Buchanan's pluggers at 1 mm increments from the tip to the 4 mm length of shank. The heat control spring was touched for 5 seconds, and temperature rise on the surface of the pluggers were measured at 1 sec intervals for more than 5 seconds with an accuracy of 0.01 using Data Logger. The data were statistically analyzed by one-way ANOVA. The results were as follows. 1. The position at which the temperature peaked was approximately at 1~2 mm far from the tip of Buchanan plugger (p<0.01). 2. The peak temperature was 215.25±2.28℃ in F plugger, 185.94±2.19℃ in FM plugger, 169.51±9.12℃ in M plugger, and 160.79±1.27℃ in ML plugger and the peak temperature was highest in F plugger and followed by, in descending order, FM plugger, M plugger. ML plugger showed the lowest peak temperature (p<0.01). 3. The temperature on the pluggers was decreased with the increase of touching time. This results suggest that the actual temperature on the surface of the pluggers dose not correlate well with the temperature set on digital display. Heat concentrates around the up. The larger plugger reveals lower temperature rise relatively.

Continuous Wave of Condensation Technique으로 근관충전시 치근면 온도상승 분석

김영주,황윤찬,김선호,황인남,최보영,정영진,정우남,오원만 大韓齒科保存學會 2003 Restorative Dentistry & Endodontics Vol.28 No.4

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 1mm 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℃, 200℃, 250℃ and 300℃ 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℃, 200℃, 250℃ and 300℃ on the digital display of System B HeatSource, the real temperature of the plugger at the 1mm point from the tip revealed 130.82±2.96℃ 158.00±5.26℃, 215.93±6.91℃ and 249.88±3.65℃ 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<0.01). 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±0.09℃ at 150℃ setting, 3.11±0.12℃ at 200℃ setting, 3.93±0.09℃ at 250℃ setting and 5.69±0.15℃ at 300℃ 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℃, 200℃, 250℃ and 300℃ temperature settings on digital temperature display of System B HeatSource.

레진모형 근관에서 Ni-Ti 파일로 근관성형 후 거타퍼챠콘의 근관내 삽입깊이에 대한 연구

조현구,황윤찬,황인남,오원만 大韓齒科保存學會 2007 Restorative Dentistry & Endodontics Vol.32 No.6

본 연구는 레진모형 만곡근관에서 여러 가지 엔진구동형 Ni-Ti파일로 근관성형 후,같은 경사도를 가진 수종의 거타퍼챠콘을 적용시 근관 내 삽입 깊이에 대해 비교, 분석해보고자 시행하였다. 레진 모형근관으로 J자의 근관형태가 재현된 ENDO-TRAINING BLOCK 50개를 사용하여 각각 10개씩 1) ProFile .04 taper #25, 2) ProFile .06 taper #25, 3) ProTaper F2, 4) HEROShaper .04 taper #25, 5) HEROShaper .06 taper #25 파일로 최종 근관성형 하였다. 거타퍼챠콘은 META (META Biomed, Korea), Sure-Endo (SUREDENT, Korea) 그리고 DiaDent (DiaDent Group International Inc., Canada)의 .04 및 .06 경사도의 콘을 사용하였으며 선택된 거타퍼챠콘의 직경 및 경사도를 측정하였다. ProFile과 HEROShaper로 성형한 레진블록에는 사용된 Ni-Ti 파일의 경사도에 맞는 제조회사별 .04 및 .06 경사도의 거타퍼챠콘을 10개씩 근관에 적용하였으며, ProTaper로 성형한 레진블록에는 경사도와 무관하게 제조회사별 .04 및 .06 경사도의 거타퍼챠콘을 10개씩 적용하였다. 거타퍼챠콘을 근관 내 적용한 상태에서 스캐너를 이용하여 이미지를 얻은 후 이미지 분석 프로그램을 사용하여 근첨에서 거타퍼챠콘 첨부까지의 거리를 측정하였고 다음의 결과를 얻었다. HEROShaer를 이용하여 근관성형 한 경우 ProFile 및 ProTaper보다 거타퍼챠콘의 근관 내 적합성이 우수하게 나타났으며, 근관성형 시 .04 taper HEROShaper로 근관성형 후에는 META 거타퍼챠콘 및 Sure-Endo 거타퍼챠콘을, .06 taper HEROShaper로 근관성형 후에는 DiaDent 거타퍼챠콘을 마스터콘으로 사용시 근관 내 적합성이 우수하게 나타났다. 따라서 근관성형 후 사용한 Ni-Ti 파일과 같은 경사도를 가진 거타퍼챠콘이 근관에 알맞게 위치되는 것은 아니며 근관충전 시 적절한 마스터콘의 선택이 필요함을 시사한다. The purpose of this study was to evaluate the insertion depth of several brands of master gutta percha cones after shaping by various Ni-Ti rotary files in simulated canals. Fifty resin simulated J-shape canals were instrumented with ProFile, ProTaper and HEROShaper. Simulated canals were prepared with ProFile .04 taper #25 (n = 10), .06 taper #25 (n = 10), ProTaper F2 (n = 10), HEROShaper .04 taper #25 (n = 10) and .06 taper #25 (n = 10). Size #25 gutta percha cones with a .04 & .06 taper from three different brands were used: DiaDent; META; Sure-endo. The gutta percha cones were selected and inserted into the prepared simulated canals. The distance from the apex of the prepared canal to the gutta percha cone tip was measured by image analysis program. Within limited data of this study, the results were as follows 1. When the simulated root canals were prepared with HEROShaper, gutta-percha cones were closely adapted to the root canal. 2. All brands of gutta percha cones fail to go to the prepared length in canal which was instrumented with ProFile, the cones extend beyond the prepared length in canal which was prepared with ProTaper. 3. In canal which was instrumented with HEROShaper .04 taper #25, Sure-endo .04 taper master gutta percha cone was well fitted (p < 0.05). 4. In canal which was instrumented with HEROShaper .06 taper #25, META .06 taper master gutta percha cone was well fitted (p ( 0.05). As a result, we concluded that the insertion depth of all brands of master gutta percha cone do not match the rotary instrument, even though it was prepared by crown-down technique, as recommended by the manufacturer. Therefore, the master cone should be carefully selected to match the depth of the prepared canal for adequate obturation.