• Restorative Dentistry and Endodontics
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• 제7권1호
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• pp.125-130
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• 1981

The purpose of this study is to determine the effect of concentration and temperature on the bactericidal action of sodium hypochlorite by means of comparing the killing time of several kinds of microorganism on each different concentration and temperature of sodium hypochlorite. The results were as follows: 1. As the concentration of sodium hypochlorite was increased, the bactericidal action of sodium hypochlorite was increased in all specimens. 2. The bactericidal action of sodium hypochlorite at $37^{\circ}C$ was more potent than that of sodium hypochlorite at $21^{\circ}C$. 3. Among the 3 experimental microorganisms, Pseudomonas aeruginosa was the most resistant to sodium hypochlorite, then comes staphylococcus aureus, and the least resistant microorganism was Streptococcus mutans.

• 한국미생물·생명공학회지
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• 제51권1호
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• pp.32-36
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• 2023

In this study, the effect of sodium hypochlorite on biofilm removal was evaluated using three bacterial strains; Aeromonas hydrophila, Streptococcus mutans, and Yersinia enterocolitica. For maximum biofilm removal in 10 min, sodium hypochlorite is required at 1.65, 0.83, and 0.41 g/l for A. hydrophila, S. mutans, and Y. enterocolitica, respectively. Resistance to sodium hypochlorite was increased by the biofilms of all three tested strains, while the change in bactericidal activity according to sodium hypochlorite concentration was strain-specific. Therefore, we aimed to determine the effective concentration of sodium hypochlorite required for hygiene, considering that higher concentrations are needed to remove biofilms than to kill cells.

• Journal of Veterinary Science
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• 제22권1호
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• pp.11.1-11.7
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• 2021

Background: The spore-forming bacterium Bacillus anthracis causes anthrax, an often-fatal infection in animals. Therefore, a rapid and reliable strategy to decontaminate areas, humans, and livestock from B. anthracis is very critical. Objectives: The aim of this study was performed to evaluate the efficacy of sodium hypochlorite, calcium hypochlorite, and quaternary ammonium compound (QAC) sanitizers, which are commonly used in the food industry, to inhibit spores and vegetative cells of B. anthracis surrogate. Methods: We evaluated the efficacy of sodium hypochlorite, calcium hypochlorite, and a QAC in inhibiting vegetative cells and spores of a B. anthracis surrogate. We treated a 0.1-mL vegetative cell culture or spore solution with 10 mL sanitizer. The samples were serially diluted and cultured. Results: We found that 50 ppm sodium hypochlorite (pH 7), 1 ppm calcium hypochlorite, and 1 ppm QAC completely eliminated the cells in vegetative state. Exposure to 3,000 ppm sodium hypochlorite (pH 7) and 300 ppm calcium hypochlorite significantly eliminated the bacterial spores; however, 50,000 ppm QAC could not eliminate all spores. Conclusions: Calcium hypochlorite and QAC showed better performance than sodium hypochlorite in completely eliminating vegetative cells of B. anthracis surrogate. QAC was ineffective against spores of the B. anthracis surrogate. Among the three commercial disinfectants tested, calcium hypochlorite most effectively eliminated both B. anthracis vegetative cells and spores.

• 한국유체기계학회 논문집
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• 제20권2호
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• pp.69-74
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• 2017

Sodium hypochlorite, used as water disinfectant, is generated by electrolysis of salt. Compared to chlorine gas disinfection, it is free from high-pressure gas regulation and does not generate toxic gas, so it is increasingly used as a safe disinfectant. Despite these advantages, the concentration of sodium hypochlorite decreases with temperature during long-term storage, and the amount of chlorate increases when a large amount is added, it has mainly been applied to small-scale waterworks. To solve this problem, high sodium hypochlorite generation was developed. In this study, the changes of concentration and chlorate of sodium hypochlorite with time has been studied. As a result of the test, it was found that the usable period of sodium hypochlorite produced at a certain temperature or less was increased from 1.5 days to 13 days. Overall, sodium hypochlorite can be applied even in large-scale waterworks, which makes operation more stable and also reduces the disinfection byproducts, thus it contributed greatly to securing water quality.

• 식물병연구
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• 제20권4호
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• pp.259-263
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• 2014

차아염소산나트륨의 벼 키다리병 종자소독제로서 활용 가능성을 구명하고자, 항균 활성 효과와 종자소독 효과를 연구한 결과, 차아염소산나트륨이 높은 항균 활성을 나타내어 $100{\mu}l/l$ 이상의 농도에서 균총이 형성되지 않았으며 $80{\mu}l/l$ 농도에서도 균 총형성이 현저히 낮았다. 벼 키다리병균 감염 벼 종자를 차아염소산나트륨 0.3% 농도로 8시간 침지 처리 시 종자소독효과가 90%로 높았다. 또한 차아염소산나트륨 0.5%, 0.3% 용액에 감염종자를 각각 12시간 처리하였을 벼 키다리병 발병율이 4.3%, 4.7%로 무처리 발병율 97.3%에 비해 현저히 억제되었으며, 유묘 출현율이 무처리 대비 29.1%, 26.9% 높았다. 그리고 벼 키다리병이 발생하여 자연 감염된 주남벼 종자를 사용하여 차아염소산나트륨 처리한 후 prochloraz 처리와, prochloraz를 처리한 후 차아염소산나트륨 처리의 종자 감염율이 각각 4.0%, 6.3% 로서 prochloraz 단독처리 13.7% 보다 낮은 경향을 보였으며, 벼 키다리병 발병율도 각각 3.7%, 8.3% 로 prochloraz 단독처리 14.3% 보다 낮았다. 아울러 차아염소산나트륨을 처리한 후 prochloraz를 처리한 것에서 더 높은 종자소독효과를 보였다.

• Restorative Dentistry and Endodontics
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• 제8권1호
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• pp.115-121
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• 1982

Sodium hypochlorite solution has been widely used as endodontic irrigant due to its ability to dissolve pulp tissue debris and its antimicrobial action. This in vitro study was conducted to evaluate the solvent action of sodium hypochlorite solution on vital pulp tissue under various conditions include concentration, exposure time, and temperature. The percentage of weight loss due to pulp tissue dissolution was calculated with weight difference of lyophilized specimens before and after the exposure to test solutions. The results were as follows; Statistical analysis indicated that the ability of both 5.0% and 2.5% sodium hypochlorite solutions to dissolve pulp tissue was significantly greater than that of distilled water, but no significant difference was found between 5.0% and 2.5% sodium hypochlorite solutions. There was no significant increase in the pulp tissue dissolving ability of sodium hypochlorite solutions; as exposure time increased 2 minutes, 5 minutes, and 10 minutes. Of the given temperatures, no significant difference was found in the solvent aciton of sodium hypochlorite solution on pulp tissue between $20^{\circ}C$ (room temperature) and $37^{\circ}C$(body temperature).

• Mycobiology
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• 제28권3호
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• pp.123-126
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• 2000

Sodium hypochlorite alkaline was tested against Pseudomonas tolaasii causing bacterial blotch on cultivated oyster mushroom (Pleurotus ostreatus). The minimum inhibitory concentration of sodium hypochlorite against P. tolaasii contained active chlorine (AC) at 1.4 mg/l on plate assay. The highest cultivation yield was obtained from the treatment of AC 5.7 mg/l. Treatment of sodium hypochlorite at the rate of higher than AC 11.4 mg/l resulted in reduced yields at the harvest. However, the population of total bacteria on the bed surface treated with AC 5.7 mg/l of sodium hypochlorite was maintained to some extent. Inhibitory concentration against total bacteria on the bed surface was over AC 22.8 mg/l. Mushroom mycelium was damaged and its growth strongly inhibited at the concentration of AC 200 mg/l. Mushroom caps showed yellowish symptom by chemical injury by treatments of AC 74.1 mg/l or higher. Sporocarps infected by P. tolaasii were irrevocable at any concentration of sodium hypochlorite. Routine watering with AC 5.7 mg/l from mushroom initiation to the end of picking resulted in reduced bacterial blotch incidence of 40% and 86% at two mushroom farms. The treatment resulted in higher quality mushroom production compared to that conventionally watered with tap water alone.

• 웰빙융합연구
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• 제6권3호
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• pp.33-36
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• 2023

Purpose: Since the food wastewater contains a high concentration of nitrogen, it is very important to find a way to efficiently remove it. Research design, data and methodology: A total of four experiments were conducted under different conditions to remove ammonia nitrogen present in the food wastewater. The experiment was designed by adding sodium hypochlorite to the raw food wastewater and varying conditions such as pH control, aeration/precipitation, and stirring. Results: The ammonia nitrogen removal rate in Experiment 1 was about 12% (sodium hypochlorite added), ammonia nitrogen increased about 4.7% in Experiment 2 (sodium hypochlorite added after aeration/precipitation in a bioreaction tank, stirring), and decreased about 52.5% (sodium hypochlorite added after controlling and stirring). Conclusions: When the concentration of sodium hypochlorite was high, ammonia nitrogen was best removed, and the pH was adjusted to 12, and sodium hypochlorite was added after stirring, and the removal was the second best. If the method of this study is further studied and developed, it can be basic data for ammonia nitrogen removal in the future.

• Restorative Dentistry and Endodontics
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• 제28권5호
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• pp.425-430
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• 2003

The purpose of this study was to evaluate the clinical applications of the Sodium Dichloroisocyanurate effervescent tablet as a routine root canal irrigant by performing several in vitro tests such as $Cl^{-}$ content. cytotoxicity. antimicrobial effect as well as its pH level compared to the equivalent concentration of sodium hypochlorite solution. 1. Sodium Dichloroisocyanurate demonstrated lower level of $Cl^{-}$ concentration than each dilution of sodium hypochlorite solution. Both solution has increased level of $Cl^{-}$ as the concentration of each solution increased. There was no significant change of $Cl^{-}$ concentration in sodium hypochlorite as time goes by. However. $Cl^{-}$ concentration in Sodium Dichloroisocyanurate was increased. 2. The antimicrobial effects of both solutions were increased when their concentrations were increased. One day after dilution. antimicrobial effect of Sodium Dichloroisocyanurate was slightly higher than sodium hypochlorite. however. there was no difference in 1 week dilution solution. One month dilution solution of sodium hypochlorite still retain its activity. but antimicrobial effect of Sodium Dichloroisocyanurate was drastically decreased 1 month after dilution. 3. The cytotoxicity of Sodium Dichloroisocyanurate was rather higher than same concentration of sodium hypochlorite solution until 1 week after dilution. Then in 1 month. cytotoxicity of Sodium Dichloroisocyanurate was decreased than that of 1 week dilution solution. especially 4% Sodium Dichloroisocyanurate solution has almost no toxicity. However. 1% and 2% sodium hypochlorite solution has unchanged moderate degree of cytotoxicity after the dilution. Furthermore. 4% sodium hypochlorite solution showed high level of toxicity. 4. The pH level of Sodium Dichloroisocyanurate showed that the solution was weak acid (pH5). On the other hand. sodium hypochlorite was revealed as a strong alkaline solution (pH12). There was no change in pH following the dilution of each solution. As results. Sodium Dichloroisocyanurate solution fully satisfy the basic requirements as a root canal irrigation solution. However. we strongly recommend to use this solution clinically in low concentration and try to apply into the root canal within 1 week after dilution.

• Restorative Dentistry and Endodontics
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• 제14권2호
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• pp.103-110
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• 1989

The purpose of this study was to evaluate the cleansing effect of Glyoxide on the dentinal walls of the root canal. Fourty teeth were divided into four groups and the canals in each group were individually enlarged with K-file by step-back technic and irrigated with one of four irrigants. The four used irrigants were Glyoxide (Marion lab. U.S.A.) in combination with 3.5% sodium hypochlorite, 3.5% sodium hypochlorite, 3.5% sodium hypochlorite in combination with 3% hydrogen peroxide and normal saline solution. All the irrigants were used in conjunction with instrumentation as they would be during clinical conditions. After final irrigation, the canals were dried with paper points and the teeth were split longitudinally. The cleaness of canal walls according to the size and the level of canals were evaluated under steroscope by t analysed statistically The results were as follows. 1. The use of 3.5% sodium hyphochlorite in combination with 3.0% hydrogen peroxide revealed the most clean canal surface regardless of the size of canal at apical third of root canal (p < 0.05). 2. Glyoxide in combination with 3.5% sodium hyphchlorite showed no significant difference in cleaning effect of canal surface compared with 3.5% sodium hypochlorite and normal saline solution at the apical third of narrow canal. 3. Glyoxide in combination with 3.5% sodium hypochlorite revealed no significant difference in debridement of canal walls compared with 3.5% sodium hypochlorite in combination with 3% hydrogen peroxide and saline solution at the middle third of narrow and large canals.