• Title/Summary/Keyword: Free Radical Mechanism

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The Effects of Pro-inflammatory Cytokines by Cisplatin on the Death of Sensory Hair Cells. (시스플라틴에 의한 염증성 사이토카인의 청각유모세포 사멸 효과)

  • Lee, Jeong-Han;Park, Chan-Ny;Park, Rae-Kil
    • Journal of Life Science
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    • v.18 no.4
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    • pp.542-549
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    • 2008
  • Cisplatin (cis-diamminedichloroplatinum II : CDDP) is the most widely used anticancer drug against a variety of human neoplasms. However, its clinical use is limited by the onset of severe side effects, including ototoxicity and nephrotoxicity. Even though a number of evidences in cytotoxic mechanism of cisplatin have been suggested, the role of pro-inflammatory cytokines in cisplatin cytotoxicity of auditory cells has not yet been demonstrated. Herein our data clearly demonstrated that cisplatin decreased the viability of HEI-OC1 auditory cells, which was inhibited by the addition of neutralizing $anti-TNF-{\alpha}$, $anti-IL-1{\beta}$ and anti-IL-6 antibodies. Consistently, Neutralization with antibodies against pro-inflammatory cytokines ameliorated the cell death and disarrangement of cochlea hair cell layers in the rat primary cochlear explants which were treated with cisplatin. Furthermore, exogeneous supplementation with free radical scavengers, including GSH and NAC, significantly prevented the cytotoxicity of cisplatin in the rat primary cochlea explants. We also observed that $TNF-{\alpha}$ was predominantly expressed in Deiters and Hensen's cells located in hair cell zone of cisplatin-treated cochlear explants. These findings suggest that pro-inflammatory cytokines, including $TNF-{\alpha}$, $IL-1{\beta}$ and IL-6, may play a pivotal role in the pathophysiology of hair cell damages caused by ototoxic drug cisplatin.

Protective Mechanism of Flavonoids Isolated from Rhus verniciflua on the Biliary Liver Fibrosis in Rat (간섬유화 동물에서 옻나무 목부로부터 분리한 flavonoids의 독성 경감기전)

  • 최종원;박희준;이경태;박건영;한갑이;정민화
    • Journal of Life Science
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    • v.12 no.3
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    • pp.332-339
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    • 2002
  • The pathogenesis of cholestatic liver injury as well as the modulation of hepatic fibrogenesis is causally associated with involvement of reactive oxygen species and free radical reactions. In this study, we investigated whether flavonoids (fustin, sulfuretin) which were isolated from Rhus verniciflua Stokes (RCS) have antioxidant and antihepatotoxicity effect under the biliary liver fibrosis condition. After surgery (control) and posttreated RCS methanol extract (250mg/kg), ethyl acetate extract (250mg/kg) and flavonoids were administered p.o. 10mg/kg/day in two weeks for control groups. The concentration of clinical parameters and product of hepatic lipid peroxidation and the hydroxyproline content were significantly increased in liver fibrosis developed rats. Among the clinical parameters of serum, value of ALT, AST, SDH, total bilirubin and ${\gamma}$ -GT in posttreated RCS components-group showed significantly lower than in control-group. The content of hydroxyproline in posttreated RCS components-group showed lower than in control group and then the value of MDA in posttreated RCS components-group was also significantly reduced to 40~60% of that in control group. The hepatic xanthine oxidase and aldehyde oxidate activities were posttreated RCS components-group showed significantly lower than in control-group. The hepatic SOD and glutathione peroxidase activities were posttreated RCS components-group showed significantly higher than in control-group. Hence we concluded that active components of fustin and sulfuretin which were isolated from R. verniciflua Stokes were hepatoprotective effect in experimental liver fibrosis.

Suppressive Effect of Yongdamsagantanggamibang on the Inflammatory Factors (용담사간탕가미방(龍膽瀉肝湯加味方) 3종(種)의 염증관련 인자 억제에 관한 연구)

  • Lee, Seung-Jun;Cho, Han-Baek;Kim, Song-Baeg;Jang, Yun-Jeong;Lee, Su-Jeong;O, Kwang-Woo;Choe, Chang-Min
    • The Journal of Korean Obstetrics and Gynecology
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    • v.22 no.3
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    • pp.51-65
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    • 2009
  • Purpose: The purpose of this study is to investigate the anti-inflammatory effects of three types of Yongdamsagantanggamibang(YSTG) which has been medicated the patient with inflammatory disease of female genitourinary system. Methods: To verify the anti-inflammatory mechanism of YSTGs, expressions of IL-1${\beta}$, IL-6, MCP-1, COX-2 and TNF-${\alpha}$ mRNA in THP-1 cells were examined. And we investigated the production levels of IL-1${\beta}$, IL-6 and TNF-${\alpha}$ in mouse following LPS co-treatment. Results: 1. YSTG1, YSTG2 and YSTG3 extract did not show any cytotoxic effect on human fibroblast cells at any of the concentrations evaluated(500, 250, 125, 62.5, 37.25 ${\mu}g/m{\ell}$) 2. YSTG1, YSTG2 and YSTG3 extract showed scavenging activity on DPPH free radical and SOD-like activity. 3. YSTG1, YSTG2 and YSTG3 extract decreased production levels of IL-1${\beta}$, IL-6, IL-8, TNF-${\alpha}$ and MCP-1 in LPS-treated THP-1 cells. 4. YSTG1, YSTG2 and YSTG3 extract decreased expressions of IL-1${\beta}$, IL-6, MCP-1, COX-2 and TNF-${\alpha}$ mRNA in LPS-treated THP-1 cells. 5. YSTG1, YSTG2 and YSTG3 extract decreased production levels of IL-1${\beta}$, IL-6 and TNF-${\alpha}$ in serum of LPS-treated mouse. Conclusion: Based on results above, it is revealed three types of YSTG have the anti-inflammatory effect, and may be effective in the treatment for inflammatory disease of female genitourinary system.

A Theoretical Study for Estimation of Oxygen Effect in Radiation Therapy (방사선 조사시 산소가 세포에 미치는 영향의 이론적 분석)

  • Rena J. Lee;HyunSuk Suh
    • Progress in Medical Physics
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    • v.11 no.2
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    • pp.157-165
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    • 2000
  • Purpose: For estimation of yields of l)NA damages induced by radiation and enhanced by oxygen, a mathematical model was used and tested. Materials and Methods: Reactions of the products of water radiolysis were modeled as an ordinary time dependant equations. These reactions include formation of radicals, DNA damage, damage repair, restitution, and damage fixation by oxygen and H-radical. Several rate constants were obtained from literature while others were calculated by fitting an experimental data. Sensitivity studies were performed changing the chemical rate constant at a constant oxygen number density and varying the oxygen concentration. The effects of oxygen concentration as well as the damage fixation mechanism by oxygen were investigated. Oxygen enhancement ratio(OER) was calculated to compare the simulated data with experimental data. Results: Sensitivity studies with oxygen showed that DNA survival was a function of both oxygen concentration and the magnitude of chemical rate constants. There were no change in survival fraction as a function of dose while the oxygen concentration change from 0 to 1.0 x 10$^{7}$ . When the oxygen concentration change from 1.0 $\times$ 107 to 1.0 $\times$ 101o, there was significant decrease in cell survival. The OER values obtained from the simulation study were 2.32 at 10% cell survival level and 1.9 at 45% cell survival level. Conclusion: Sensitivity studies with oxygen demonstrated that the experimental data were reproduced with the effects being enhanced for the cases where the oxygen rate constants are largest and the oxygen concentration is increased. OER values obtained from the simulation study showed good agreement for a low level of cell survival. This indicated that the use of the semi-empirical model could predict the effect of oxygen in cell killing.

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Effects of Aminotriazole on Lung Toxicity of Paraquat Intoxicated Mice (Paraquat중독에 의한 폐독성에 미치는 Aminotriazole의 영향)

  • Lee, Seung-Il;An, Gi-Wan;Chung, Choon-Hae
    • Tuberculosis and Respiratory Diseases
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    • v.41 no.3
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    • pp.222-230
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    • 1994
  • Background: Paraquat, a widely used herbicide, is extremely toxic, causing multiple organ failure in humans. Paraquat especially leads to irreversible progressive pulmonary fibrosis, which is related to oxygen free radicals. However, its biochemical mechanism is not clear. Natural mechanisms that prevent damage from oxygen free radicals include changes in glutathione level, G6PDH, superoxide dismutase(SOD), catalase, and glutathione peroxidase. The authors think catalase is closely related to paraquat toxicity in the lungs Method: The effects of 3-amino-1,2,4-triazole(aminotriazole), a catalase inhibitor, on mice administered with paraquat were investigated. We studied the effects of aminotriazole on the survival of mice administered with paraquat, by comparing life spans between the group to which paraquat had been administered and the group to which a combination of paraquat and aminotriazole had been administered. We measured glutathion level, glucose 6-phosphate dehydrogenase(G6PDH), superoxide dismutase(SOD), catalase, and glutathione peroxidase(GPx) in the lung tissue of 4 groups of mice: the control group, group A(aminotriazole injected), group B(paraquat administered), group C(paraquat and aminotriazole administered). Results: The mortality of mice administered with paraquat which were treated with aminotriazole was significantly increased compared with those of mice not treated with aminotriazole. Glutathione level in group B was decreased by 20%, a significant decrease compared with the control group. However, this level was not changed by the administration of aminotriazole(group C). The activity of G6PDH in all groups was not significantly changed compared with the control group. The activities of SOD, catalase, and glutathione peroxidase(GPx) in the lung tissue were significantly decreased by paraquat administration(group B); catalase showed the largest decrease. Catalase and GPX were significantly decreased by aminotriazole treatment in mice administered with paraquat but change in SOD activity was not significant(group C). Conclusion: Decrease in catalase activity by paraquat suggests that paraquat toxicity in the lungs is closely related to catalase activity. Paraquat toxicity in mice is enhanced by aminotriazole administration, and its result is related to the decrease of catalase activity rather than glutathione level in the lungs. Production of hydroxyl radicals, the most reactive oxygen metabolite, is accelerated due to increased hydrogen peroxide by catalase inhibition and the lung damage probably results from nonspecific tissue injury of hydroxyl radicals.

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Effect of Riboflavin Tetrabutylate on the Activity of Drug Metabolizing Enzyme and Lipid Peroxidation in Liver Microsomes of Rats (Riboflavin Tetrabutylate가 약물대사 효소 및 지질 과산화효소에 미치는 영향)

  • Lee, H.W.;Kim, W.J.;Hong, S.S.;Kwack, C.Y.;Hong, S.U.
    • The Korean Journal of Pharmacology
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    • v.16 no.2 s.27
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    • pp.45-53
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    • 1980
  • Lipid peroxidation in vitro has been identified as a basic deteriorative reaction in cellular mechanism of aging processes, such as air pollution oxidant damage to cell and to the lung, chlorinated hydrocarbon hepatotoxicity. Many experimental evidences were reported by several investigators that lipid peroxidation could be one of the principle causes for the hepatotoxicity produced by $CCl_4$. It is now reasonably established that $CCl_4$ is activated to a free radical in vivo, that lipid peroxidation occurs very quickly in microsomes prepared from damaged livers, that the peroxidation is associated with loss of enzyme activity of microsomes, and that various antioxidants can protect animals against the hepatotoxic effect of $CCl_4$. Recent studies have drawn attention to some other feature of microsomal lipid peroxidation. Incubation of liver microsomes in the presence of NADPH has led to a loss of cytochrome $P_{450}$. However, the presence of an antioxidant prevented lipid peroxidation and preserved cytochrome $P_{450}$. Decrease of cytochrome $P_{450}$ in microsomes under in vitro incubation can be enhanced by $CCl_4 and these changes were parallel to a loss of microsomal polyunsaturated fatty acid and formation of malonaldehyde. The primary purpose of this experiment was to study the effect of riboflavin tetrabutylate on lipid peroxidation, specially, the relationship between lipid peroxidation and drug metabolizing enzyme system which is located in smooth endoplasmic recticulum as well as the effect of ritoflavin tetrabutylate on drug metabolizing enzyme system of animal treated with $CCl_4$. Albino rats were used for experimental animal. In order to induce drug metabolizing enzyme system, phenobarbital was injected intraperitoneally. $CCl_$ and riboflavin tetrabutylate were given intraperitoneally as solution in olive oil. Microsomal fraction was isolated from liver of animals and TBA value as well as the activity of drug metabolizing enzyme were measured in the microsomal fractions. The results are summerized as following. 1) The secobarbital induced sleeping time of $CCl_4$ treated rat was about 2 times longer than that of the control group. However, the pretreatment with riboflavin tetrabutylate inhibited completely the lengthened sleeping time due to $CCl_4$ treatment. Furthermore TBA value was significantly increased in $CCl_4$ treated rat in comparison to control group tut the increase of TBA value was prevented by the pretreatment with riboflavin tetrabutylate. On the other hand, the activity of hepatic drug metabolizing enzyme was decreased in $CCl_4$ group, however, the pretreatment with riboflavin tetrabutylate also prevented the decrease of the enzyme activity caused by $CCl_4$. 2) The effect of riboflavin tetrabutylate on TBA value and the activity of drug metabolizing enzyme in vitro was similar to in vivo results. Incubation of liver microsome from rat in the presence of $CCl_4$, $Fe^{++}$, or ascorbic acid has led to the marked increase of TBA value, however, the addition of riboflavin tetrabutylate in incubation mixture prevented significantly the increase of TBA value, suggesting the inhibition of lipid peroxidation. In accordance with TBA value, the activity of drug metabolizing enzyme was inhibited in the presence of $CCl_4$, $Fe^{++}$, ascorbic acid but the addition of riboflavin tetrabutylate protected the loss of the enzyme activity in microsome under in vitro incubation.

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Decomposition of odor using atmospheric-pressure plasma (플라즈마를 이용한 악취물질 분해 특성)

  • Kang, Seok-Won;Lee, Jae-Sik;Lee, Kang-San;Lim, Hee-Ah;Kim, Ji-Seong;Lee, Jeong-Dae;Park, Wol-Su;Park, Young-Koo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.7
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    • pp.708-718
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    • 2020
  • Offensive odor is recognized as a social environmental problem due to its olfactory effects. Ammonia(NH3), hydrogen sulfide(H2S) and benzene(C6H6) are produced from various petrochemical plants, public sewage treatment plants, public livestock wastes, and food waste disposal facilities in large quantities. Therefore efficient decomposition of offensive odor is needed. In this study, the removal efficiency of atmospheric-pressure plasma operating at an ambient condition was investigated by evaluating the concentrations at upflow and downflow between the plasma reactor. The decomposition of offensive odor using plasma is based on the mechanism of photochemical oxidation of offensive odor using free radical and ozone(O3) generated when discharging plasma, which enables the decomposition of offensive odor at ordinary temperature and has the advantage of no secondary pollutants. As a result, all three odor substances were completely decontaminated within 1 minute as soon as discharging the plasma up to 500 W. This result confirms that high concentration odors or mixed odor materials can be reduced using atmospheric-pressure plasma.

New Whitening Agent From Pimpinella brachycarpa (참나물추출물의 멜라닌 생성저해 효과)

  • Kim, Jin-Hwa;Sim, Gwan-Sub;Lee, Dong-Hwan;Lee, Geun-Soo;Lee, Bum-Chun;Pyo, Hyeong-Bae
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.33 no.3
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    • pp.203-208
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    • 2007
  • To develop a new whitening agent for cosmetics from natural products, Pimpinella brachcarpa was selected for its inhibitory effect on melanogenesis in B16 melanoma cells. Crude ethanolic extract of P. brachycarpa and its four fractions-hexane, ethyl acetate(EtOAc), butanol and aqueous were evaluated for antioxidative effects and tyrosinase inhibitory activity. To elucidate the mechanism of active compounds of P. brachycarpa, we investigated the changes in protein level of tyrosinase, TRP-1 and TRP-2 using Western blotting and the changes in mRNA level of tyrosinase using RT-PCR technique. Following UV irradiation, expression of ET-1 in HaCaT keratinocytes was measured by quantitative enzyme immunoassay(EIA) using human ET-1 antibody. Crude ethanolic extract of P. brachycarpa and its four fractions-hexane, EtOAc, butanol and aqueous had free radical scavenging effect by 87.2, 2.5, 97.2, 80.5, 49.8% at 100 ${\mu}g/mL$ and tyrosinase inhibitory effect by 18.3, 15.1, 55.4, 13.1, 0 % at 100 ${\mu}g/mL$. P. brachycarpa EtOAc fraction significantly inhibited melanin production in B16 melanoma cells. Treatment with P. brachycarpa extract for 72 h suppressed the biosynthesis of melanin up to 58 % at 100 ${\mu}g/mL$. Especially, the EtOAc fraction of P. brachycarpa reduced the tyrosinase activity and tyrosinase expression in B16 melanoma cells in a dose-dependent manner. mRNA levels of tyrosinase and TRP-1 were markedly reduced by the EtOAc fraction of P. brachycarpa. Moreover, at the concentrations of $12.5{\sim}50{\mu}g/mL$ of the fraction, the production of UV-induced ET-1 in HaCaT keratinocytes(24 h after 8 $mJ/cm^2$ UVB irradiation) was reduced about 40%(p<0.05). P. brachycarpa could be used as a new natural skin-whitening agent due to the inhibitory effect of on melanin biosynthesis and endothelin-1 expression.

Effects of ischemic preconditioning, KATP channel on the SOD activation and apoptosis in ischemic reperfused skeletal muscle of rat (허혈양상화와 KATP 통로가 허혈후 재관류된 흰쥐의 골격근육에서 SOD 활성 및 apoptosis에 미치는 영향)

  • Abn, Dong-choon;Paik, Doo-jin;Yang, Hong-hyun
    • Korean Journal of Veterinary Research
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    • v.39 no.5
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    • pp.878-895
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    • 1999
  • Ischemic preconditioing (IPC), i.e., a preliminary brief episode of ischemia and reperfusion, has been shown to reduce the cell damage induced by long ischemia and reperfusion. Superoxide radical which is produced during reperfusion after ischemia was recognized as a factor of the ischemic injury and it is dismutated into $H_2O_2$ and $O_2$ by two types of intracellular superoxide dismutase (SOD), Cu,Zn-SOD in cytoplasm and Mn-SOD in mitochondria. Recently oxygen free radicals are suggested to induce the apoptosis, however mechanism of the reduced apoptosis by ischemic preconditioing was unknown, while many studies performed in mammalian heart indicated that ATP-sensitive $K^+$ ($K_{APT}$) channel activation related with the protective effects. The aim of present study is to investigate 1) whether IP upregulate the Cu,Zn-SOD and Mn-SOD activities, and 2) whether ischemic preconditioning decreases apoptosis via $K_{APT}$ channel activation in timely reperfused skeletal muscle after long ishemia. The experimental animals, Sprague-Dawley rats weighing 250~300g, were divided into 8 groups; 1) control group, 2) ischemic preconditioning only groups, 3) pinacidil, a $K_{APT}$ channel opener, treatment only groups, 4) glibenclamide, a $K_{APT}$ channel blocker, treatment only groups, 5) ischemia groups, 6) ischemia after IPC groups, 7) ischemia and pinacidil treatment groups, and 8) IP and ischemia after glibenclamide pretreatment groups. Animals of the control group were administered with the vehicle (DMSO) alone. Pinacidil (1mg/kg) was administered intravenously 5 minutes after initiation of ischemia, and glibenclamide (0.5mg/kg) was injected intravenously 20 minutes before IPC. In rats that were ischemic preconditioned, the left common iliac artery was occluded for 5 minutes followed by 5 minutes of reperfusion by three times using vascular clamp. Ischemia was done by occlusion of the same artery for 4 hours. The specimens of left rectus femoris muscle were obtained immediately (0 hour), 12 hours, 24 hours after drug administrations, IP or ischemia and reperfusion. The immunoreactivities of SOD and its alterations were observed by use of sheep antihuman Cu,Zn-SOD and Mn-SOD antibodies on the $10{\mu}m$ cryosections. The incidencies of apoptosis were observed by TUNEL methods with in situ apoptosis detection kit on $6{\mu}m$ paraffine section. The results obtained were as follows : 1. After IPC, immunoreactivities of Cu,Zn-SOD mainly in the small-sized fibers were increased by 24 hours, that of Mn-SOD at 0 hour and 24 hours. 2. No significant changes in immunoreactivities of SOD was observed in the pinacidil and in the glibenclamide treatment only groups, and in the ischemia only groups. 3. The immunoreactivities of the Cu,Zn-SOD were increased in the ischemia after IPC groups and the ischemia and pinacidil treatment groups. 4. The immunoreactivities of the Cu,Zn-SOD in the IPC and ischemia after glibenclamide pretreatment groups were not increased except for the 12 hours reperfusion group. But, Mn-SOD immunoreactivities were increased in the 0 hours, 12 hours and 24 hours after reperfusion. 5. In the control group, the IPC only groups, and the pinacidil treatment only groups, negative or trace apoptotic reactions were observed, but the positive apoptotic reaction occured in the glibenclamide treatment groups. 6. Moderate or many number of apoptosis were revealed in the ischemia groups, and also the IPC and ischemia after glibenclamide pretreatment group except for 12 hours and 24 hours after reperfusion. However, the incidence of apoptosis was decreased in the ischemia after IPC groups and in the ischemia and pinacidil treatment groups. 7. There is a coincidence between the increase of Cu,Zn-SOD immunoreactivities and the decrease of apoptosis in the presence of ischemia and reperfusion. These results suggest that the protective effects of ishemic preconditioing may related to the SOD activation, and the ischemic preconditioning decreases the apoptosis partially via $K_{APT}$ channel activation in timely reperfused rat skeletal muscle. It is also suggested that inhibition of apoptosis by IPC may related with the SOD activation.

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THE EFFECT OF CONCENTRATION AND APPLICATION TIME OF HYDROGEN PEROXIDE ON THE MICROTENSILE BOND STRENGTH OF RESIN RESTORATIONS TO THE DENTIN AT DIFFERENT DEPTHS (과산화수소의 농도와 적용시간이 상아질의 깊이에 따라 레진 수복물의 미세인장결합강도에 미치는 영향)

  • Son, Jeong-Lyong;Lee, Gye-Young;Kang, Yu-Mi;Oh, Young-Taek;Lee, Kwang-Won;Kim, Tae-Gun
    • Restorative Dentistry and Endodontics
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    • v.34 no.5
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    • pp.406-414
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    • 2009
  • The purpose of this study was to examine the effect of hydrogen peroxide at different application time and concentrations on the microtensile bond strength of resin restorations to the deep and the pulp chamber dentin. A conventional endodontic access cavity was prepared in each tooth, and then the teeth were randomly divided into 1 control group and 4 experimental groups as follows: Group 1, non treated; Group 2, with 20% Hydrogen peroxide ($H_2O_2$); Group 3, with 10% $H_2O_2$; Group 4, with 5% $H_2O_2$; Group 5, with 2.5% $H_2O_2$; the teeth of all groups except group 1 were treated for 20, 10, and 5min. The treated teeth were filled using a Superbond C&B (Sun medical Co., Shiga, Japan). Thereafter, the specimens were stored in distilled water at $37^{\circ}C$ for 24-hours and then sectioned into the deep and the chamber dentin. The microtensile bond strength values of each group were analyzed by 3-way ANOVA and Tukey post hoc test(p < 0.05). In this study, the microtensile bond strength of the deep dentin (D1) was significantly greater than that of the pulp chamber dentin (D2) in the all groups tested. The average of microtensile bond strength was decreased as the concentration and the application time of $H_2O_2$ were increased. Analysis showed significant correlation effect not only between the depth of the dentin and the concentration of $H_2O_2$ but also between the concentration of H202 and the application time(p < 0.05), while no significant difference existed among these three variables(p > 0.05). The higher $H_2O_2$ concentration, the more opened dentinal tubules under a scanning electron microscope(SEM) examination.