• 한국식품저장유통학회지
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• 제16권2호
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• pp.292-298
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• 2009

본 연구에서는 새싹종자 소독처리 여부에 따른 재배기간별 미생물 오염도 수준을 파악하고, 종자소독이 발아율에 미치는 영향을 분석하였다. 수입산 새싹종자 알팔파(alfalfa), 브로콜리(broccoli), 클로버(clover), 적양배추(red cabbage), 적무(red radish) 5종에 대하여 소독제 처리 여부에 따른 발아율과 재배기간별 미생물 분석을 실시하였다. 소독제 종류에 관계없이 새싹종자(알팔파, 클로버, 적무)는 48시간 후 90% 이상 높은 발아율을 보였다. 종자 소독 시 식중독균은 검출되지 않았고, 대조군에 비하여 유의하게 낮은 미생물 수준을 보였으나, 발아과정에서 일반세균, 대장균군 모두 $10^7-10^8CFU/g$으로 종자소독 여부에 관계없이 종자에 비하여 유의하게 높은 오염 수준을 나타내었다(p<0.05). 또한 종자 소독하지 않은 클로버에서 Listeria monocytogenes 이 검출되었다. 따라서 새싹채소의 위생적인 안전성을 개선하기 위하여 미국 FDA 권고에 따라 재배전 종자의 소독이 필요하며, 발아과정의 HACCP 관리계획을 마련하여 중점적으로 관리하는 것이 필요하겠다.

• 대한소아치과학회지
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• 제41권4호
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• pp.335-343
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• 2014

재생적 근관치료는 치수 괴사를 보이는 미성숙 영구치 치료에 있어서 괴사된 치수를 치유하고 계속되는 치근의 발달을 유도할 수 있다. 그러나 여기에는 몇 가지 단점과 불리한 결과들이 있다. 이 중 재생적 근관치료에 가장 큰 임상적 부작용은 minocycline과 MTA에 의한 변색이다. 본 증례에서는 재생적 근관치료 후에 나타나는 치관 변색을 방지하기 위해 minocycline을 clindamycin으로 대체한 triple antibiotics와 칼슘 지르코늄 알루민산염 시멘트인 Retro MTA를 사용하였다. 치수 괴사된 미성숙 영구치에서 근관 와동 형성 및 근관 세척 후 수정된 triple antibiotics를 적용하고, 혈병 또는 콜라겐 스펀지를 스캐폴드(scaffold)로 하여 Retro MTA로 근관을 폐쇄하였다. 정기적인 검진 결과 미성숙 영구치의 치근 성장 및 정상적인 치아 주위 조직들이 관찰되었으며, 치관 변색 없이 모두 양호한 치유 결과를 얻었다.

• Restorative Dentistry and Endodontics
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• 제43권1호
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• pp.11.1-11.10
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• 2018

Objectives: This study aimed to introduce the use of laser-induced breakdown spectroscopy (LIBS) for evaluation of the mineral content of root canal dentin, and to assess whether a correlation exists between LIBS and scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS) methods by comparing the effects of irrigation solutions on the mineral content change of root canal dentin. Materials and Methods: Forty teeth with a single root canal were decoronated and longitudinally sectioned to expose the canals. The root halves were divided into 4 groups (n = 10) according to the solution applied: group NaOCl, 5.25% sodium hypochlorite (NaOCl) for 1 hour; group EDTA, 17% ethylenediaminetetraacetic acid (EDTA) for 2 minutes; group NaOCl+EDTA, 5.25% NaOCl for 1 hour and 17% EDTA for 2 minutes; a control group. Each root half belonging to the same root was evaluated for mineral content with either LIBS or SEM/EDS methods. The data were analyzed statistically. Results: In groups NaOCl and NaOCl+EDTA, the calcium (Ca)/phosphorus (P) ratio decreased while the sodium (Na) level increased compared with the other groups (p < 0.05). The magnesium (Mg) level changes were not significant among the groups. A significant positive correlation was found between the results of LIBS and SEM/EDS analyses (r = 0.84, p < 0.001). Conclusions: Treatment with NaOCl for 1 hour altered the mineral content of dentin, while EDTA application for 2 minutes had no effect on the elemental composition. The LIBS method proved to be reliable while providing data for the elemental composition of root canal dentin.

• Restorative Dentistry and Endodontics
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• 제45권2호
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• pp.4.1-4.6
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• 2020

Although numerous studies have been conducted on apexification using mineral trioxide aggregate (MTA), direct observation of extracted human teeth after the procedure has been rarely reported. This case report describes a mandibular premolar treated 2.5 years ago and extracted recently for orthodontic treatment. The tubercle of the right mandibular premolar of a 12-year-old boy with dens evaginatus was fractured and the pulp was exposed. The tooth was diagnosed with pulp necrosis and asymptomatic periapical abscess. During the first visit, copious irrigation was performed with 2.5% sodium hypochlorite. Calcium hydroxide paste was placed as an intracanal medicament. The sinus tract had disappeared at the second visit after 3 weeks. MTA was applied on to the bleeding point as a 4-mm-thick layer, followed by a 3-mm-thick gutta-percha filling and resin core build-up. After 2.5 years, the tooth and three other premolars were extracted for orthodontic treatment. The right and left mandibular premolars were scanned with micro-computed tomography to determine the root shape and canal anatomy. Irregular root growth was observed and the root outline of the right mandibular premolar differed from that of the contralateral tooth. Apexification with MTA leads to the formation of roots with irregular morphology, without any pulpal space.

• 한국환경보건학회지
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• 제43권2호
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• pp.143-156
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• 2017

The purpose of this study was to investigate water quality through a field survey at six floor fountain sites. The floor fountain facilities were designed and operated in such a way that tap water was stored in a water tank and recycled repeatedly. The water tank was cleaned once or twice per week in the summer. The number of facility users was low during the day due to sweltering heat, but up to 40 people, mainly children, were using them around 8 pm. Since the operation time was as short as 30 minutes, it is considered necessary to extend it for at least one hour for the number of users. As a result of the water quality test of the reservoir tank prior to operation after cleaning, it was measured to be within drinking water quality standards at the six facilities. As a result of the water quality test after use, ammonia nitrogen was measured to be 1.45 mg/L at Site IV. This exceeded the drinking water quality standard of 0.5 mg/L. In the case of turbidity, two cases exceed at 7.38 and 4.52 NTU when applying 4 NTU as the water quality standard for waterscape facilities. Twenty-eight cases exceed the standard of drinking water quality. The result of microbiological tests, at five sites excepting Site I, where disinfectant was injected, was that the maximum total colony count was 180,000 CFU/mL, total coliforms was 2,100,000 CFU/100 mL, fecal coliforms was 4,600 CFU/100 mL, Escherichia coli was 170 MPN/100 mL and Enterococcus was 100 CFU/100 mL. This exceeded the water quality standards of drinking water. Children are very likely to inhale because the water spews from below and falls from above, so it is necessary to apply water quality standards for ammonia nitrogen, turbidity and microbes. Current floor fountain facilities are highly susceptible to disease caused by microbial contamination because of water cycling and reuse, so it is necessary to change the water every day, clean the water tank, and perform chlorination. Therefore, it is necessary to inject calcium hypochlorite according to the free chlorine water quality standard of swimming pools with a different water tank capacity. In addition, facilities should be improved to prevent the reuse of water by installing the water tank at a separate location.