• Restorative Dentistry and Endodontics
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• v.27 no.6
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• pp.569-576
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• 2002

This study was peformed to evaluate the interfacial shear bond strength of base (direct and indirect) and repair composites with aging and surface treatment methods. Direct composite resin specimens ($Charisma^{\circledR}$, Heraeus Kulzer, Germany) were aged for 5 min, 1 hour, 24 hours, and 1 week in $37^{\circ}C$ distilled water before surface treatment, and then divided into five groups Group 1, grinding; Group 2, grinding and application of bonding agent, Group 3, grinding, etching with 37% phosphoric acid for 30sec, and application of bonding agent, Group 4, grinding, etching with 37% phosphoric acid for 30sec, silane treatment, and application of bonding agent ; Group 5, grinding, etching with 4% hydrofluoric acid for 30sec. silane treatment, and application of bonding agent. Indirect composite resin specimens ($Artglass^{\circledR}$, Heraeus Kulzer, Germany) were aged for 1 week in $37^{\circ}C$ distilled water and divided into seven groups Group 1 - Group 5, equal to Charisma specimens; Group 6, grinding, etching with 37% phosphoric acid for 60sec, silane treatment, and application of bonding agent; Group7, grinding, etching with 4% hydrofluoric acid for 60 sec, silane treatment, and application of bond-ing agent. The repair material($Charisma^{\circledR}$) was then added on the center of the surface (5 mm in diameter. 5 mm in height). The shear bond strength was tested and the data was analyzed using one-way ANOVA and the Student- Newman-Keuls test. The following conclusions were drawn. 1 The shear bond strength of $Charisma^{\circledR}$ specimens aged for 1 hour was significantly higher in Group 2 and Group 5 than in Group 1 (p<0.05), and that of $Charisma^{\circledR}$ specimens aged for 1 week was signifi-cantly higher in Group 3 and Group 5 than in Group 1 (p<0.05). No significant difference was found in the bond strength of specimens aged for 5 min and 24 hours. 2. In Group 2 of the $Charisma^{\circledR}$ specimens, there was significant difference between the bond strength of 24 hours and that of 1 week (p<0.05). 3. In Group 4 of the $Charisma^{\circledR}$ specimens, the shear bond strength of specimens aged for 24 hours was significantly higher than the others(p<0.05) 4. There was no significant difference between the shear bond strength of the $Artglass^{\circledR}$ specimens, 5. Most of the $Charisma^{\circledR}$ specimens showed cohesive fractures. Artglass^{\circledR}$ specimens that were etched with acid (phosphoric or hydrofluoric) for 30 sec showed more cohesive fractures.

• Restorative Dentistry and Endodontics
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• v.29 no.5
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• pp.439-445
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• 2004

The purpose of this study was to evaluate the influence of plugger penetration depth on the apical extrusion of root canal sealer during root canal obturation with Continuous Wave of Condensation Technique. Root canals of forty extracted human teeth were divided into four groups and were prepared up to size 40 of 0.06 taper with ProFile. After drying. canals of three groups were filled with Continuous Wave of Condensation Technique with System $B^{TM}$ and different plugger penetration depths of 3. 5, and 7 mm from the apex. Canals of one group were filled with cold lateral compaction technique as a control. Canals were filled with non-standardized master gutta-percha cones and 0.02 mL of Sealapex. Apical extruded sealer was collected in a container and weighed. Data was analyzed with one-way ANOVA and Duncan's Multiple Range Test. 3 and 5 mm penetration depth groups in Continuous Wave of Condensation Technique showed significantly more extrusion of root canal sealer than 7 mm penetration depth group (p < 0.05). However, there was no significant difference between 7 mm depth group in Continuous Wave of Condensation Technique and cold lateral compaction group (p < 0.05). The result of this study demonstrates that deeper plugger penetration depth causes more extrusion of root canal sealer in root canal obturation by Continuous Wave of Condensation Technique. Therefore, special caution is needed when plugger penetration is deeper in the canal in Continuous Wave of Condensation Technique to minimize the amount of sealer extrusion beyond apex.

• Restorative Dentistry and Endodontics
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• v.29 no.5
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• pp.446-453
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• 2004

The aim of this study was to evaluate the shaping abilities of four different rotary nickel-titanium instruments with anticurvature motion to prepare root canal at danger zone by measuring the change of dentin thickness in order to have techniques of safe preparation of canals with nickel-titanium files. Mesiobuccal and mesiolingual canals of forty mesial roots of extracted human lower molars were instrumented using the crown-down technique with ProFile, $GT^{TM}$ Rotary file, Quantec file and $ProTaper^{TM}$. In each root, one canal was prepared with a straight up-and-down motion and the other canal was with an anticurvature motion. Canals were instrumented until apical foramens were up to size of 30 by one operator. The muffle system was used to evaluate the root canal preparation. After superimposing the pre- and post-instrumentation canal. change in root dentin thickness was measured at the inner and outer sides of the canal at 1. 3, and 5 mm levels from the furcation. Data were analyzed using two-way ANOVA. Root dentin thickness at danger zone was significantly thinner than that at safe zone at all levels (p < 0.05). There was no significant difference in the change of root dentin thickness between the straight up-and-down and the anticurvature motions at both danger and safe zones in all groups (p > 0.05). ProTaper removed significantly more dentin than other files especially at furcal 3 mm level of danger and safe zones (p < 0.05) Therefore, it was concluded that anticurvature motion with nickel-titanium rotary instruments does not seem to be effective in danger zone of lower molars.

• Restorative Dentistry and Endodontics
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• v.27 no.4
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• pp.441-447
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• 2002

The bleaching of discolored nonvital teeth is conservative treatment that satisfy the cosmetic desire. The most common method for this treatment, walking bleaching, is using 30% hydrogen peroxide and sodium perborate. Many alternatives are suggested for preventing the external cervical root resorption that is the common complication of the nonvital teeth bleaching with 30% hydrogen peroxide The same extent of oxidation reactions as that resulted by the bleaching with the application of 30% hydrogen peroxide and sodium perborate can also be acquired more safely by materials that contain 10% carbamide peroxide, used primarily for the bleaching of vital teeth. Therefore, this study was performed to evaluate the efficacy of 10% and 15% carbamide peroxide bleaching gel in nonvatal teeth bleaching. The internal bleaching of intentionally discolored teeth was performed in vitro with 10% carbamide peroxide (Group 1), 15% carbamide peroxide (Group 2), mixture of distilled water and sodium perborate (Group 3), and mixture of 30% hydrogen peroxide and sodium perborate (Group 4). The bleaching materials were refreshed following 3, 6, 9 and 12 days. To evaluate the bleaching effect, the color change of the crowns was measured at 1, 2, 3, 4, 7 and 15 days of bleaching using the colorimeter. The results were as follows：1. L$^*$ and $\Delta$E$^*$ values were increased with time in all bleaching agents (p<0.01). 2. There was no significant difference in L$^*$ and $\Delta$E$^*$ value among bleaching agents. 3. $\Delta$E$^*$ value higher than 3 was shown after 3 days of bleaching with 10% carbamide peroxide gel, 1 day with 15% carbamide poroxide gel, 4 days with mixture sodium perborate and distilled water and 4 days with mixture sodium perborate and 30% hydrogen peroride, respectively. These results revealed that the use of 10% and 15% carbamide peroxide bleaching gel in non-vital teeth bleaching is as effective as mixture of distilled water and sodium perborate and mixture of 30% hydrogen peroxide and sodium perborate. Accordingly, carbamide peroxide could be used clinically to bleach discolored non-vital teeth.

• Restorative Dentistry and Endodontics
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• v.31 no.2
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• pp.119-124
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• 2006

The purpose of this study was to evaluate the effect of newly developed endodontic root canal cleanser (MTAD) on the apical leakage of obturated root canal using an electrochemical method. Canals of 60 extracted single-rooted human teeth were prepared by using a crown-down technique with rotary nickel-titanium files. In Group 1 (positive control group) and 2 (negative centre) group), 5.25% NaOCl was used as a canal irrigant and no canal wall treatment was done. In group 3 only 5.25% NaOCl were used as canal irrigant, canal wall treatment and final rinse. In group 4, specimens were irrigated with 5.25% NaOCl, treated with 5 ml of 17% EDTA for 5 minutes and final rinsed with 5.25% NaOCl Specimens of group 5 were irrigated with 1 3% NaOCl and treated with 5 ml of MTAD for 5 minutes. All root canals are dried with paper points and obtuated with gutta-percha and AH plus as a sealer using a continuous wave of condensation technique except in the group 1. The electrical resistance between the standard and experimental electrodes in canals was measured over a period of 10 days. Rising of apical leakage with time was observed for all the groups. Group 4 and 5 showed lower apical leakage than group 3 but differences between the group 3, 4 and 5 were no statistical significance at any measurement time.

• Investigative Magnetic Resonance Imaging
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• v.13 no.2
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• pp.127-136
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• 2009

Purpose : Functional magnetic resonance imaging (fMRI) was used to assess the temporal response of neural activation in healthy subjects while they performed the Iowa Gambling Test (IGT), which utilizes decisions involving ambiguity and risk. The IGT was divided into five blocks of 20 trials; analysis showed that activity in the medial prefrontal cortex (mPFC) moves gradually from the dorsal to the ventral mPFC over the course of the IGT. These findings suggest that cognitive division of the mPFC, including the dorsal portion of the anterior cingulated cortex (ACC), plays a major role in ambiguous decision making and that the aspect of the IGT corresponding to risky decision making is associated with significant activity within the corticolimbic network strongly implicated in emotion and reinforcement. Our results also suggest that decisions made under ambiguity and decisions made under risk situations can be further divided into sub-phases based on the neural network involved.

• Journal of Hospice and Palliative Care
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• v.13 no.1
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• pp.7-12
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• 2010

Purpose: To evaluate medications at the end of life care for terminal cancer patients during their last admission. Methods: Medical records of terminal cancer patients during their last admission from July 2003 to April 2008 at a district academic hospital were evaluated. Patient's characteristics, therapeutic drug classification during their last admission and on the patient's day of death, and the administrated route and number of medications on the patient's day of death were analyzed. Results: Total 81 patients were included. The median patient age was 63 years. The median length of admission was 18 days (range: 1~101). 54% of the patients had more than one comorbidities. The most frequently prescribed drugs during the last admission were opioid analgesics (63%), followed by antibiotics (58%) and antacids (53%). On the day of death, common medications were antibiotics (59%), antacids (58%), and opioid analgesics (46%). Intravenous injection was given to 81% of the patients and intramuscular injection was given to 16% of the patients on the day of patient's death. Number of medications prescribed to patients was between 0 and 11 (median: 3) and 12% (10/81) of the patients took over 8 medications including intravenous and oral drugs on the day of death. 6% (5/81) of the patients took potentially futile medications, like multivitamin or statin until the day of death. Conclusion: This study suggests that potentially futile medications and uncomfortable care were given to terminal cancer patients. Multicenter-based studies are necessary to diminish futile medications by essential medication at the end of life care for terminal cancer patients.

• Biomolecules & Therapeutics
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• v.17 no.4
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• pp.388-394
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• 2009

The cytokines which is produced by allergen-specific T helper (Th) cells play a pivotal role in the pathogenesis of asthma. Asthma is caused by exaggerated T-helper 2 (Th2)-based immune responses. It is suggested that controlling such Th2-based response is necessary for asthma therapy. The current therapies for asthma focus primarily on control of symptoms and suppression of inflammation, without affecting the underlying cause. So, we examined that anti-asthmatic drugs might have play a certain role in Th2/Th1 balance. Splenocytes isolated from ovalbumin (OVA)-sensitized mice cultured with anti-asthmatic drugs. It is well known that Th2 and Th1 immune responses can balance one another, as Th2 mediators suppress Th1 responses and Th1 mediators similarly inhibit Th2 responses. But salmeterol inhibits both of Th1 and Th2 mediators, which salmeterol is a suppressor of immune responses not only a suppressor of Th2-based immune responses. Aminophylline is a weak suppressor of immune responses. But ipratropium and cromoglycate don't have any suppressor effect to Th2-driven responses. They only have suppressor effect to Th1 immune responses. Salmeterol, ipratropium, aminophylline, and cromoglycate augmented mRNA levels of CRTH2, EP2, and IP2 receptors in OVA-sensitized splenocytes. It is well known that the up-regulation of CRTH2 - $PGD_2$ receptor - results in restraint of eosinophil recruitment and that the increment of IP and EP2 - $PGI_2$ and $PGE_2$ receptor, respectively - may induce the accumulation of cAMP that decrease the effector function of T cells. Moreover salmeterol and cromoglycate increase the mRNA expression of $PGD_2$ synthase. These findings indicate that anti-asthma agents may alleviate the immunological responses that cause the asthmatic diseases.

• Biomolecules & Therapeutics
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• v.17 no.4
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• pp.403-411
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• 2009

Thiacremonone, the main component isolated from heated garlic (Allium sativum L.), is interested for using as a cancer preventive or therapeutic agent since garlic has been known to be useful plant in the treatment of cancers. Nuclear factor kappaB (NF-${\kappa}B$) is constitutively activated in the prostate cancer and activation of NF-${\kappa}B$ is implicated in drug resistance in cancer cells. Docetaxel, a semisynthetic analog of paclitaxel, is an antineoplastic drug widely used for advanced various cancer. In previous studies, we found that thiacremonone inhibited activation of NF-${\kappa}B$ in cancer cells and marcrophages. In the present study, we investigated whether thiacremonone could increase susceptibility of prostate cancer cells (PC-3 and DU145) to docetaxel via inactivation of NF-${\kappa}B$. We found that the combination treatment of thiacremonone (50 ${\mu}g$/ml) with docetaxel (5 nM) was more effective in the inhibition of prostate cancer cell growth and induction of apoptosis accompanied with the significant inhibition of NF-${\kappa}B$ activity than those by the treatment of thiacremonone or docetaxel alone. It was also found that NF-${\kappa}B$ target gene expression of Bax, caspase-3 and caspase-9 was much more significantly enhanced, but the expression of Bcl-2 was also much more significantly inhibited by the combination treatment. These results indicate that thiacremonone inhibits NF-${\kappa}B$, and enhances the susceptibility of prostate cancer cells to docetaxel. Thus, thiacremonone could be useful as an adjuvant anti-cancer agent.

• Journal of Periodontal and Implant Science
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• v.33 no.3
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• pp.359-372
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• 2003

Among objectives of periodontal therapy. the principal one is the morphological and functional reconstruction of lost periodontal supporting tissues. This includes de novo formation of connective tissue attachment and the regrowth of alveolar bone. The use of enamel matrix derivative(EMD) may be a suitable means of regeneration new periodontal attachment in the infrabony defects. Implant used to replace lost tooth but, implantitis occurred after installation. The purpose of this study was to investigate the effects of EMD on differentiation and growth of osteoblast in titanium disc. Twentyfive millimeter diameter and 1mm thick Ti disc which was coated 25, 50, 100, 200${\mu}g$/ml of EMD(Emdogain(R)) used as experimental group, 25, 50, 100, 200ng/d of rhBMP-2 as positive control group, and no coat as negative control group. A human osteosarcoma cell line Saos-2 was cultured in Ti disc and cell proliferation and Alkaline phosphatase (ALP) activity were measured at 1 and 6 days. PCR was performed at 2 and 8 hours. Semi-quantitative RT-PCR for mRNA expressions of various osteoblastic differentiation markers -type I collagen, ALP, osteopontin, and bone sialoprotein - were performed at appropriate concentrations based upon the results of MTT and ALP assay. Cultured cell-disc complexes were prepared for scanning electron microscopy (SEM) at 2 hour. Data were analyzed using Mann-Whitney and repeated- measures 1-way analysis of variance(SPSS software version 10,SPSS. Chicago. IL). After culture, there was more osteoblast in EMD100${\mu}g$/ml than in EMD50, 200${\mu}g$/ml on day 6. There was significant difference in experimental and positive control group compared control group, as times go by(1 and 6 days). Alkaline phosphatase activity was different significantly in EMD100, 200${\mu}g$/ml and BMP100, 200${\mu}g$/ml on day 6. The results of reverse transcriptase-polymerase chain reaction (RT-PCR) showed that expression of mRNA for ALPase, collagen type I, osteopontin. hone sialoprotein and BMP-2 was detected at 2 hour and 8 hour in EMI 200${\mu}g$/ml subgroup and BMP100ng/ml subgroup. The results of this study suggest that application of enamel matrix derivative on osteoblast attached to titanium surface facilitate the expression of bone specific protein and the differentiation and growth of osteoblast.