• Restorative Dentistry and Endodontics
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• 제38권2호
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• pp.93-97
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• 2013

During root canal preparation procedures, the potential for instrument breakage is always present. When instrument breakage occurs, it leads to anxiety of the clinician and as well as a metallic obstruction of the canal which hinders further cleaning and shaping. Separated instruments must always be attempted for retrieval and if retrieval is not possible bypass should be tried. With the increased use of nickel-titanium (NiTi) instruments the incidence of separated instruments has increased. A considerable amount of research has been done to understand the various factors related to the fracture of NiTi instruments to minimize its occurrence. This paper presents a review of the literature regarding the fracture of NiTi instruments and also describes a case report showing the use of a modified 18-guage needle and cyanoacrylate glue to retrieve a separated NiTi instrument from the mesiolingual canal of a mandibular first molar.

• Restorative Dentistry and Endodontics
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• 제36권5호
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• pp.431-435
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• 2011

상악 견치는 다른 치아보다 해부학적 변이가 적으며, 보통 하나의 치근과 하나의 근관을 가진다. 이 연구는 이전에 거의 보고되지 않은 2개의 분리된 근관을 가진 상악 견치의 방사선 사진과 CT(컴퓨터 단층촬영)를 이용한 근관치료에 관한 증례보고이다. 비록 적절한 근관치료가 행해졌다고 해도, 치아의 해부학적 변이가 고려되지 않았기 때문에 심한 통증이 있을 수 있다. 따라서 임상가는 근관의 수가 이 경우처럼 명백한 경우의 치아에서도 근관치료 시 근관시스템의 해부학적 변이 가능성을 잘 알고 있어야 한다.

• 대한소아치과학회지
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• 제40권2호
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• pp.127-132
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• 2013

외상에 의한 미성숙 영구치의 손상은 유치열에서 영구치열로 이환되는 8~10세경에 가장 빈발하며 전체 외상 환자의 높은 빈도를 차지한다. 외상에 대한 결과는 치아의 파절, 전위, 함입, 정출, 탈구 등의 경조직 손상 뿐 아니라 치수, 치주인대, Hertwig 상피 근초, 치조골, 치은 및 구강점막 등의 치아 인접조직의 손상도 포함한다. 일반적으로 Hertwig 상피 근초는 외상성 손상에 취약하지만, 때때로 감염이나 외상에 의한 손상을 견디고 생활력을 유지하여 치근성장에 대한 정상적인 기능을 수행하는 것이 보고된 바 있다. 본 증례에서는 외상에 의해 완전 탈구된 미성숙 영구치를 가진 두 명의 환자에 대해 보고하고자 한다. 첫 번째 환자의 경우 탈구된 상악 중절치를 재식하였고 두 번째 환자의 경우 탈구된 하악 중절치를 재식하지 않았다. 하지만 두 환자 모두에서 탈구된 치아의 치조와 부위에 분리된 치근의 계속적인 성장을 보이는 바 이를 보고하고자 하며, 나아가 계속적인 치근형성에 있어서 미성숙 치수 조직과 Hertwig 상피 근초의 생활력 보존이 결정적임을 알리고자 한다.

• Restorative Dentistry and Endodontics
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• 제7권1호
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• pp.59-63
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• 1981

Ninety four human mandibular third molars were chosen to study the anatomy of the root canal. The experimental teeth were injected with china ink, decalcified, cleared and used in study, in vitro, to determine the number of root, the number of root canals, canals per root, frequency and location of transverse anastomoses, frequency and location of lateral canals and frequency of the apical deltas. The results were as follows: 1. Most of the teeth showed two canals, but 17.0% of the teeth were found to have one canal, 17.0% of them three canals, 3.2% of them four canals and l.1% of them five canals. 2. In so far as observing one canal per root, 17.0% of the teeth were found to have one canal in single-rooted tooth, 48.9% of them in mesial root and 58.5% of them in distal root. 3. In roots with two or three canals, the separated apical foramen appeared in 55.6% in single-rooted tooth, 64.3% in mesial side and 80.0% in distal side, and the common apical foramen appeared in 44.4% in single-rooted tooth, 35.7% in mesial side and 20.0% in distal side. 4. Of the two root canals in one root, 19.1% of the canals were found to have transverse anastomoses and were usually located in the apical third of the root. 5. 63.8% of 94 teeth were found to have lateral canals, and ramifications were mainly located in the apical third of the root.

• Restorative Dentistry and Endodontics
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• 제3권1호
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• pp.7-11
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• 1977

One hundred and thirteen human mandibular first molars were injected with china ink, decalcified, cleared and used in study, in vitro, to determine the number of root, the number of root canals, canals per root, frequency and location of transverse anastomoses, frequency and location of lateral canals and frequency of the apical deltas. The results were as follows; 1. Most of the teeth showed three canals, but 21. 25% of the teeth were found to have two canals and 21. 25% of them four canals. 2. In so far as observing two canals per root, 77.0% of teeth were found to have two canals in mesial root and 25.7% of them in distal root. 3. In roots with two canals, the separated apical foramen appeared 59.8% in mesial side and 40.0% in distal side, and the common apical foramen 40.2% in mesial side and 60.0% in distal side. 4. Of the two root canals in one root, 37.3% of the canals were found to have transverse anastomoses and were usually located in the apical third of the root. 5. 25.7% of 113 teeth were found to have lateral canals, and ramifications were mainly located in the apical third of the root.

• 대한치과의사협회지
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• 제21권6호통권169호
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• pp.467-472
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• 1983

Thirty seven human maxillary third mooars were injected with china ink, decalcified, cleared, and used in vitro study to determine the number of root canals the frequency and location of lateral canals, canals per root, and frequency of apical deltas. The results were as follows: 1. Less than half of the examined teeth showed 3 roots and 3 canals. 2. The mesiobuccal root was ound to contain a single primary canal in 65.4% of the teeth examined and two canals in 34.6% of the teeth studed. 3. In mesiobuccal roots with two canals, the separated apical foramen appeared 30.8% of the specimen concerned, but no common apical foramen appeared. 4. Of the 106 canals studied, 46.2% of the canals were found to contain lateral canals and these ramifications were mainly located in the apical third of the root.

• 한국연초학회지
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• 제16권1호
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• pp.20-25
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• 1994

The volatile components were extracted from root of Cnidium officinale M. by SDE(Simultaneous steam distillation and extraction) apparatus and analyzed by GC/M.5 and GC retention index matching. The experimental results revealed the presence of over 22 volatile components. Major components were cnidilide (35.1%), neocnidilids (13.4%), ligustilide (23.2%). The essential oils were separated by silica gel column chromatography(Merck 70-230mesh), and 4 fractions among 12 fractions separated had a, good aroma character.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2019년도 추계학술대회
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• pp.21-21
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• 2019

Approximately 80% of rice field in Africa conducts in rainfed (Nishimaki 2017). The rice is damaged by water stress because fields like rainfed lowland repeat drying and humidity of soil because of impossible water control. Then water stress is one of the major limiting factors for decreasing rice yield. So, in initial growth stage, quick and efficient root development is useful way to avoid drought stress by getting water from deeper soil layer with roots elongation as the hypothesis. Daniel et al (2016) reported that NERICA1 and NERICA4 show different patterns of root plasticity for drought stress. NERICA1 has greater development of lateral root in shallow soil layer, while NERICA4 has greater development in deep root elongation to underground. This study was aimed to evaluate the effect of root development in initial growth stage on growing NERICA1 and NERICA4 under different soil moisture condition in rainfed lowland rice field. They were grown in same water condition until 35 days after sowing (35DAS), and after that each varieties were separated in dry and wet condition. The rice plants were grown until 60DAS. The results of soil moisture, the root extension angle, shoot dry weight and bleeding ratio showed that NERICA4 can mitigate dry stress from surface soil compered to NERICA1.

• Natural Product Sciences
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• 제5권4호
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• pp.181-185
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• 1999

Higenamine is a cardiotonic constituent of Aconite root, one of the most important oriental traditional medicine. Since Aconite root contains toxic aconitine alkaloids, variously processed roots have been often used. Much works have been done with the chemical significances concerning with the toxic aconitine alkaloids during the processing periods. However, effects of processing on higenamine have not yet been previously studied. In this paper, the extract pattern and the amounts of higenamine extracted with water from unprocessed and processed Aconite roots were compared. R-(+)-isomer was the only higenamine enantiomer detected although racemic higenamine was reported to be separated from Aconitum spp. Sonication for 1 hour resulted in higher higenamine extraction $(12.3\;{\mu}g/g)$ than boiling water extraction for 3 hours $(6.7\;{\mu}g/g)$ of unprocessed Aconite root. Extraction of not only higenamine but also most of the other components of unprocessed Aconite roots were reduced with boiling in water. Similarly, reduced extraction was observed with extracts of all three processed Aconite roots (Kyung-Po-Aconite root, Dang-Po-Aconite root and Huk-Peon-Aconite root) by either sonicated extraction or boiling water extraction.

• Journal of Ginseng Research
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• 제4권1호
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• pp.55-64
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• 1980

The distribution pattern of mineral nutrients, among various Parts of Korea ginseng (Panax ginseng C.A. Meyer) was investigated to understand ginseng nutrition by simple correlation analysis. Five·year old ginseng plants grown under four different nutritional environments were sampled and separated into leaf, petiole, stem, rhizome, cortex and epidermis of tap foot, central part of tap root, cortex and epidermis of lateral root, central part of lateral root, fine root in the middle of truly, for chemical analysis. Between mineral nutrients in root, N and P showed highly significant positive correlation each other and with Mg and Cu while all other elements (K, Ca, Mg, Fe, Mn, Zn, Cu, B) showed highly significant positive correlation each other. In shoot, number of mineral nutrient pairs haying significant relation was much less than in root. (Negative: P with Ca or B, K with N, Fe, Mn or Cu, Positive: N with Mg, Fe, Mn or Cu, K with Zn, Ca with Mg, Zn, or B, Fe Mn Cu each other, Mn with B.) The number of pairs having significant correlation in whole plant was approximately the same as the number in root but three of them showed significant negative correlation. The distribution pattern similarity of mineral contents among various parts was also discussed in relation to physiological significance in Korea ginseng plant.