• Journal of the Korean Wood Science and Technology
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• 제39권1호
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• pp.15-20
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• 2011

소나무재선충병은 우리나라의 대표 수종인 소나무를 괴사시키는 주요 산림병의 하나로 재선충의 침입과 수체내에서의 이동 경로 파악은 이들의 서식 형태를 구명하는데 매우 중요하다. 따라서 본 연구에서는 감염목 내에서의 재선충 주요 서식 부위와 이동 경로를 명확히 구명하기 위해 재선충 피해목에 대한 현미경적 조사를 수행하였다. 그 결과 피해목의 특징으로는 횡단면, 방사단면, 접선단면 모두에서 주로 방사조직이 감염을 통해 진하게 착색된 것으로 드러났으며 수지구에서도 집중적인 피해가 관찰되었다. 또한 형성층과 가까운 변재 부위에서는 연륜을 따라 접선방향으로 연속 배열된 상해수지구로 보이는 특징이 관찰되었다. 재선충은 방사가도관보다는 방사유세포에서 그리고 수평수지구를 지니지 않는 단열방사조직보다는 수평수지구를 지니는 방추형방사조직에서 훨씬 더 많은 재선충이 발견되었으며 방사조직에서 가도관으로 이동하는 선충도 관찰되었다. 방사조직에서 가도관으로의 이동 시 가도관의 벽을 천공한 다음 이동하거나 크기가 작은 개구부인 측벽의 유연벽공을 통해 이동하기보다는 크기가 큰 개구부인 창상 직교분야벽공을 이동 통로로 삼는 것으로 사료되었다.

• 한국자원식물학회지
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• 제25권5호
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• pp.517-522
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• 2012

설악산 눈잣나무 천연집단은 국내 유일하게 분포하는 남방한계 분포지 수종으로 유전자원보존을 위하여 침엽의 형태적 해부학적 특성과 I-SSR 표지자를 이용한 유전변이를 조사하였다. 8가지 침엽특성에 대한 ANOVA 분석결과 모든 특성에서 개체 간에 통계적인 유의성이 인정되었다. 조사된 66개체의 평균특성은 침엽길이 53.59 mm, 침엽폭 0.78 mm, 침엽지수 68.98 및 침엽두께 0.65 mm, 최대기 공열수 4.56개, 최소기공열수 3.80개, 전체기공열수 8.36개 및 수지구수 1.71개로 각각 나타났다. 특히, 수지구는 모두 바깥쪽에 위치하는 외위 형태의 1~3개 범위로 수지구 2개 유형이 69.47%을 나타낸 반면 1개 유형은 30.45%를 나타냈다. 선발된 9개 I-SSR Primer에서 총 78개의 증폭산물을 얻었으며, 다형적 유전자좌의 비율은 61.5%, 유효대립유전자의 수 1.698개, 이형접합도의 기대치 0.388 및 Shannon의 다양성지수 0.567로 각각 나타났다.

• Journal of the Korean Wood Science and Technology
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• 제34권1호
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• pp.1-6
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• 2006

국내에 가장 많이 조림된 수종이고 중요한 국산 목재자원인 잣나무와 일본잎갈나무 두 수종의 재질특성을 구명하기 위하여 수지구와 에피델리얼세포의 수간내 변이성을 조사하였다. 그 결과, 두 수종 간에 수직수지구의 수와 그 수의 방사방향 변이성에 차이가 있었다. 일본잎갈나무의 수평수지구의 직경 및 에피델리얼세포 수도 방사방향으로 변이성을 나타냈다. 즉 미성숙재부와 성숙재부간에 수지구와 에피델리얼 세포의 출현특성이 차이가 있었다. 결론적으로, 잣나무와 일본잎갈나무에 있어서 수지구와 에피델리얼세포의 출현특성을 성숙재부와 미성숙재부로 구분하는 재질지표로 이용할 수 있을 것으로 생각하였다.

• 한국임상수의학회지
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• 제30권5호
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• pp.380-383
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• 2013

치아 골절을 가진 고양이에서 근관 치료 이후 복합레진과 포스트를 이용한 재건술의 증례이다. 내원한 고양이 3례 모두 구강검사와 치과 방사선 검사를 통해 치수가 노출된 치아 골절로 진단 되었다. 근관치료가 완료된 후, 일부 충전 물질을 제거하고 포스트를 설치하고 에칭과 본딩 전처치 후 복합 레진으로 광중합을 시행하였다. 치료된 치아들은 치과용 바와 디스크를 이용하여 성형하였으며, 6개월 동안 추시한 결과 치료된 치아들은 특별한 부작용을 발견할 수 없었다. 따라서 고양이에서 치수가 노출된 치아골절의 경우, 먼저 근관치료를 시행한 다음, 결과를 확인하고 복합 레진과 포스트를 이용한 재건술은 실시한다면 임상에 있어서 매우 좋은 효과를 거둘 수 있을 것으로 생각된다.

• Journal of the Korean Wood Science and Technology
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• 제15권2호
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• pp.79-89
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• 1987

This study was executed to examine helical structure and other feature, of Taxus cuspidata S. et Z. and Larix gmelinii var. principis-ruprechtii Pilger through photomicroscopic and scanning electron microscopic observation, and the obtained result, were summarized as follows: 1. Tracheid transition from springwood to summerwood was abrupt, mel slightly gradual in Taxus cuspidata S. et Z. and summerwood width of Larix gmelinii var. principis-ruprechtii Pilger was wider than that of Taxus cuspidata S. et Z. 2. Normal vertical and horizontal resin canals and surrounding thick epithelial cells were present in Larix gmelinii var. principis-ruprechtii Pilger but not present in Taxus cuspidata S. et Z. 3. Instead of helical thickening, helical chicks were observed only in summerwood trachieds of Larix gmelinii var. principis-ruprechtii Pilger. However, helical thickenings forming S, Z., and horizontal helix perpendicular to long axis of tracheid were observed in springood and summerwood tracheids of Taxus cuspidata S. et Z. and these helical thickenings were considered as analogous to the innermost layer of secondary wall. 4. Uniseriate and fusiform rays were appeared on tangential surface of Larix gmelinii var. principis-ruprechtii Pilger but oly uniserate ray was observed on tangential surface ot Taxus cuspidata S. et Z. The fusiform rays of Larix gmelinii var. principis-ruprechtii Pilger usually contained one horizontal resin canal bot occasionally two horizontal resin canals were contained in a fusiform ray. 5. Trabeculae and crassulae were observed in the tracheids of Larix gmelimii var. principis-ruprechtii Pilger but not observed in the tracheids of Taxus cuspidata S. et Z.

• Restorative Dentistry and Endodontics
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• 제48권3호
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• pp.28.1-28.13
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• 2023

Objectives: This study aimed to investigate the effect of the application method of 2% chlorhexidine (CHX) and its influence on the adhesion of fiberglass posts cemented with a self-adhesive resin cement. Materials and Methods: Sixty human mandibular premolars were endodontically treated and divided into 5 groups (n = 12), according to the canal irrigant and its application method: 2 groups with conventional syringe irrigation (CSI)-2.5% sodium hypochlorite (NaOCl) (control) and 2% CHX- and 3 groups with 2% CHX irrigation/activation-by passive ultrasonic irrigation (PUI), Easy Clean file, and XP-Endo Finisher file. Two roots per group were evaluated for smear layer (SL) removal by scanning electron microscopy. For other roots, fiber posts were luted using a self-adhesive resin cement. The roots were sectioned into 6 slices for push-out bond strength (BS) (7/group) and nanoleakage (NL) (3/group). Data from SL removal were submitted to Kruskal-Wallis and Student-Newman-Keuls tests (α = 0.05). Data from BS and NL were evaluated by 2-way analysis of variance and Tukey's test (α = 0.05). Results: For SL removal and BS, the CHX irrigation/activation promoted better values than CSI with CHX (p < 0.05), but it was not significantly different from CSI with NaOCl (p > 0.05). For NL, the lowest values were obtained by the chlorhexidine irrigation/activation groups (p < 0.05). Conclusions: Active 2% CHX irrigation can be used to improve the post space cleaning and adhesion before fiber post cementation with self-adhesive resin cements.

• 대한치과의사협회지
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• 제47권7호
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• pp.444-454
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• 2009

The purpose of this study was to compare the shaping abilities of LightSpeed, ProTaper-Universal, and hybrid technique using S-series of ProTaper-Universal and LigthSpeed. The 72 simulated root canals of J-shape were used and classified as flowing 3 groups according to the instrumentation methods; Group P of 24 canal blocks were prepared with ProTaper-Universal, Group L was prepared with LightSpeed, and Group H was prepared with hybrid technique (initial shaping with ProTaper-Universal SI and S2 and apical shaping with LightSpeed from #25 to #50). A second-year resident of Endodontic department prepared the resin block canals to apical size #50 (F5 in Group P). The time lapses for instrumentation and the reduction of root canal curvature after shaping were measured. The pre- and post-instrumented root canals were scanned and superimposed to evaluate and calculate the increased canal width and apical centering ratio. The results were as followings: Group Land H showed significant less instrumentation time than Group P (p < 0.05). The ProTaper system showed greater reduction of root canal curvature and working length diminishment than other methods (p < 0.05). LightSpeed system showed best canal curvature preserving characteristics. The Group P had greater instrumented widths at all levels examined (p < 0.05). Group L and Group H showed lower centering ratio (ability to preserve the canal center; the lower ratio means the better canal center preservation) than Group P (p < 0.05). Group H had the lowest centering ratio at the 1 mm level.

• Restorative Dentistry and Endodontics
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• 제15권1호
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• pp.97-105
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• 1990

When conventional root canal treatment is failed or contraindicated, retrograde root canal filling following apicoectomy is a valuable procedure, aimed at hermetically sealing the root canal against leakage of irritants from the canal into the periapical tissue. In this in vitro investigation, to analyze apical microleakage electrochemically in teeth with different retrograde filling materials and preparation types, single - rooted tooth was cut 2mm from the apex and each Class I and Slot preparation was prepared. Experimental groups : Group 1. Amalgam filling with cavity varnish in Class I preparation Group 2. Scotchbond 2+Silux filling in Class I preparation Group 3. Gutta percha filling with ZOE cement in Class I preparation Group 4. Amalgam filling with cavity varnish in Slot preparation Group 5. Scotchbond 2+Silux filling in Slot preparation Each specimens was immersed in 1% solution of KCl, and applied a potential of 9V external power supply. Measurements of the current flow were obtained at 1, 2, 3, 7, 9, 12, 14, 18, 21, 25 and 28 day after immerson. Marginal microleakage were compared and evaluated. The results were as follows ; 1. The group filled with composite resin with dentin bonding agent shows lower apical microleakage value than the group filled with amalgam following varnish application (P<0.01). 2. In the group filled with gutta percha, apical microleakage value was the hightest 3. There was no significant difference between Class I cavity and Slot type cavity regardless of the used materials.

• Restorative Dentistry and Endodontics
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• 제27권4호
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• pp.421-431
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• 2002

C-shaped canal configuration is very difficult to treat because that clues about preoperative canal anatomy cannot be ascertained from clinical crown morphology and limited information can be derived from radiographic examination. This study was done to get more informations about the root and canal configuration of C-shape root by 3-dimensionally reconstructing for the purpose of enhancing success rate of endodontic treatment. 30 mandibular molars with C-shaped root were selected. Six photo images from occlusal, apical, mesial, distal, buccal, lingual directions and radiographic view were taken as preoperative ones to compare them with 3-D image. After crown reduction to the level of 1-2mm over pulpal floor was performed, teeth were stored in 5.25% sodium hypochlorite solution for the removal of pulp tissue and debris. They were cleaned under running water, allowed to bench dry and embedded in a self-curing resin. This resin block was serially ground with a microtome (Accutom-50, Struers, Denmark) and the image of each level was recorded by digital camera (FinePix S1-pro, Fuji Co., Japan). The thickness of each section was 0.25mm. Photographs of serial sections through all root canal were digitized using Adobe Photoshop 5.0 and then minimum thickness of open and closed sites were measured (open site is the surface containing occluso-apical groove closed site is oppsite). After dizitization using 3-D Doctor (Able software Corp, USA). 3D reconstruction of the outer surface of tooth and the inner surface of pulp space was made. Canal classsification of C-shaped roots was performed from this 3-D reconstructed image. The results were as follows : 1. Most C-shape rooted teeth showed lingual groove (28/30). 2 According to Vertuccis' calssification, type I, II, III, IV, VII were observed. but also new canal types suck as 2-3-2, 1-2-3-2. 2-3-2-1, 2-3-2-3 were shown. 3 There was little difference in minimum thickness on coronal and apical portions, but open site were thinner than closed site on mid portion. Conclusively, 3D reconstruction method could make the exact configurations of C-shape root possible to be visualized and analyzed from multi-directions. Data from minimum thickness recommend cleaning and shaping be more carefully done on dangerous mid portion.

• Restorative Dentistry and Endodontics
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• 제34권3호
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• pp.208-214
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• 2009

이 연구의 목적은 서로 다른 두 개의 근관 크기(#70, #120)를 가진 레진 모형에 MTA (minoral trioxide aggregate)를 서로 다른 두 가지 방법 (수기구 충전(HC), 초음파 보조 수기구 충전(UAHC))으로 정방위 충전하고 MTA apical plug의 미세 누출을 평가하는 것이다. 직선형 근관 형태를 가지며, #70과 #120의 치근단 크기를 갖는 레진 모형을 각각 30개씩 준비하였다. 이 시편들을 MTA의 적용 방법에 따라 각 군을 2개의 아군으로 다음과 같이 분류하였다 (n=15); C70: HC + 치근단 크기 #70, C120: HC + 치근단 크기 #120, U70: UAHC + 치근단 크기 #70, U120: UAHC + 치근단 크기 #120. MTA 충전을 완료한 후에, 24시간 동안 실온에서 100% 습도를 유지하여 경화시켰다. 근관의 상부는 열연화 충전 시스템(Obtura II)을 이용하여 충전하였다. 48시간 동안 100% 습도를 유지하여 실온에서 0.2% rhodamine B 용액을 이용해 미세누출 실험을 하였다. 이 연구결과 #70의 치근단 크기를 갖는 그룹 사이에서 UAHC가 HC에 비해 미세누출이 적은 것으로 나타났다(p<0.05). 이 연구 조건하에서는 초음파 진동을 동반한 정방위 MTA apical plug 형성 방법이, 특히 좁은 근관에서 더 효율적인 것으로 사료된다.