• Restorative Dentistry and Endodontics
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• v.27 no.1
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• pp.54-65
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• 2002

Black-pigmented bacteria have been implicated in the endodontic infections. This group of microorganisms includes Porphyromonas endodontalis, Porphyromonas gingivalis, Prevotella intermedia, and Prevotella nigrescens. The organisms display a wide variety of virulence factors that may be pertinent to acute endodontic infections. The aim of this study was to identify P. endodontalis, P. gingivalis, P. intermedia, and P. nigrescens by using special potency disk test, filter paper spot test, 165 rRNA gene-directed PCR, and API 32A. Microbial samples were collected from root canals of 33 intact teeth with necrotic pulp and/or apical periodontitis. Conventional laboratory methods were used for identification of the strains of black pigmented bacteria. Eighteen of 33 samples were positive for the growth of black-pigmented bacteria Five colonies were cultured from each pure cultured colonies from Brucella agar plate. Seventy seven colonies were positive for the growth of black-pigmented bacteria. Thirty three of 77(42.6%) were identifed as P. nigrescens, 10 of 77(12.9%)were P. gingivalis, 6 of 77(7.8%) were P. endodontalis, 10 of 77(12.9%) were P. intermedia. On the contrary the reference strains of P. nigrescens, experimental strains of P nigrescens was sensitive to kanamycin in special potency disk test. 165 rRNA gene PCR and API test after rapid presumptative identification methods, such as special potency disk test and filter paper spot test, would be accurate detection methods for black-pigemented bacteria.

• The Korean Journal of Mycology
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• v.13 no.3
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• pp.179-183
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• 1985

Cylindrocarpon spp. were isolated from the soil where strawberry was grown in Suweon by soil plate method: colonies reaching 10 mm diam. in seven days at about $20^{\circ}C$; sporodochia with cream to beige to conidial slime commonly produced; conidiophore repeatedly branched and bearing subulate phialides; macroconidia cylindrical in the center part, straight or slightly curved and mostly $1{\sim}3\;septate,\;22{\sim}45\;{\times}\;5.0{\sim}6.0\;{\mu}m$; chlamydospore abundantly produced, intercalary or terminal on mycelium, singly or in chains and smooth or warted. The hypha and spore were easily fused each other on water agar. This fungus was pathogenic strawberry as a result of inoculation test. The symptom showed dwarf and yellowing at top and rotted roots under the ground. The fungus was identified as Cylindrocarpon destructans Scholten from the shape of conidiophores and conidia, mycelial growth and pathogenicity test.

• Imaging Science in Dentistry
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• v.34 no.3
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• pp.145-150
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• 2004

Purpose: To compare three digital radiographic imaging sensors by evaluating the visibility of endodontic file tips with interobserver reproducibility and assessing subjectively the clarity of images in comparison with the x-ray film images. Materials and Methods: Forty-five extracted sound premolars were used for this study. Fifteen plaster blocks were made with three premolars each and #8, 10, 15 K-flexofiles were inserted into the root canal of premolars. They were radiographically exposed using periapical x-ray films (Kodak Insight Dental film, Eastmann Kodak company, Rochester, USA), Digora imaging plates (Soredex-Orion Co., Helsinki, Finland), CDX 2000HQ sensors (Biomedisys Co., Seoul, Korea), and CDR sensors (Schick Inc., Long Island, USA). The visibility of endodontic files was evaluated with interobserver reproducibility, which was calculated as the standard deviations of X, Y coordinates of endodontic file tips measured on digital images by three oral and maxillofacial radiologists. The clarity of images was assessed subjectively using 3 grades, i.e. plus, equal, and minus in comparison with the conventional x-ray film images. Results: Interobserver reproducibility of endodontic file tips was the highest in CDR sensor (p < 0.05) only except at Y coordinates of #15 file. In the subjective assessment of the image clarity, the plus grade was the most frequent in CDR sensor at all size of endodontic file (p < 0.05). Conclusion : CDR sensor was the most superior to the other sensors, CDX 2000HQ sensor and Digora imaging plate in the evaluation of interobserver reproducibility of endodontic file tip and subjective assessment of image clarity.

• The Journal of the Korean dental association
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• v.54 no.3
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• pp.206-216
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• 2016

Objectives The aim of this study was to evaluate the antibacterial effect of xanthorrhizol (XTZ) on E. faecalis, compared with 2% chlorhexidine (CHX). Materials and Methods Normal physiological state (NS), starvation state (SS), and alkalization state (AS) of E. faecalis were used. A solution containing 1% XTZ in 30% ethanol, 1% dimethyl sulfoxide (DMSO), and 100 mg/ml sodium methyl cocoyl taurate was used and is referred to as Xan in this study. To determine the minimal bactericidal concentration (MBC) of Xan and CHX, $500{\mu}l$ of E. faecalis (NS and two stress states) was added to a microtube containing $500{\mu}l$ of serial 2-fold dilutions of 1% Xan and 2% CHX (1:2-1:128). The MBC of each antimicrobial was determined by the plate count method. Results The antibacterial effect of Xan was more effective on E. faecalis in AS than in the other states (NS, SS) at 0.125% Xan and 0.03325% Xan (P<0.05). In contrast, the antibacterial effect of CHX was more effective against E. faecalis in SS than the other states (NS, AS) at 0.0625% CHX (P<0.05). In SS, the antibacterial effect of CHX was more effective than that of Xan at 0.125% and 0.0625% (P<0.05). However, in AS, the antibacterial effect of Xan was more effective than that of CHX at 0.0625% and 0.03325% (P<0.05). Conclusions In endodontic retreatment cases in which it is important to effectively remove E. faecalis from the infected root canal, Xan may be more suitable when combined with NaOCl than CHX.

• Journal of the korean academy of Pediatric Dentistry
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• v.48 no.3
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• pp.352-358
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• 2021

Molar-incisor malformation (MIM) is characterized by malformation in the root with a normal crown. While MIM mostly occurs in the permanent first molar, it has also been reported in the maxillary central incisor and the primary second molar (PSM), but anatomical analysis of the primary teeth with MIM has not been studied to date. In this case report, a patient with MIM was reported, and an extracted PSM with MIM was analyzed with micro computed tomography (CT). A cervical constriction morphology of the cementoenamel junction (CEJ) can be observed in extracted PSM. In micro CT analysis, characteristics such a mineralized plate (cervical mineralized diaphragm) in the CEJ area, complex root canal morphologies, a calcified mass inside the pulp chamber, and constricted pulp chamber of crown portion were observed.

• The Korean Journal of Pain
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• v.37 no.3
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• pp.233-246
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• 2024

Background: Ferrostatin-1 and liproxstatin-1, both ferroptosis inhibitors, protect cells. Liproxstatin-1 decreases morphine tolerance. Yet, ferrostatin-1's effect on morphine tolerance remains unexplored. This study aimed to evaluate the influence of ferrostatin-1 on the advancement of morphine tolerance and understand the underlying mechanisms in male rats. Methods: This experiment involved 36 adult male Wistar albino rats with an average weight ranging from 220 to 260 g. These rats were categorized into six groups: Control, single dose ferrostatin-1, single dose morphine, single dose ferrostatin-1 + morphine, morphine tolerance (twice daily for five days), and ferrostatin-1 + morphine tolerance (twice daily for five days). The antinociceptive action was evaluated using both the hot plate and tail-flick tests. After completing the analgesic tests, tissue samples were gathered from the dorsal root ganglia (DRG) for subsequent analysis. The levels of glutathione, glutathione peroxidase 4 (GPX4), and nuclear factor erythroid 2-related factor 2 (Nrf2), along with the measurements of total oxidant status (TOS) and total antioxidant status (TAS), were assessed in the tissues of the DRG. Results: After tolerance development, the administration of ferrostatin-1 resulted in a significant decrease in morphine tolerance (P < 0.001). Additionally, ferrostatin-1 treatment led to elevated levels of glutathione, GPX4, Nrf2, and TOS (P < 0.001), while simultaneously causing a decrease in TAS levels (P < 0.001). Conclusions: The study found that ferrostatin-1 can reduce morphine tolerance by suppressing ferroptosis and reducing oxidative stress in DRG neurons, suggesting it as a potential therapy for preventing morphine tolerance.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.1A
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• pp.39-48
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• 2012

This study deals with numerical determination of stress intensity factors of adhesively patch-repaired plates with cracks at V-shaped or semicircular notches. The p-convergent anisoparametric model are considered and then three-dimensional virtual crack closure technique is presented using formulations of anisoparametric elements. In assumed displacement fields of an element, strain-displacement relations and three-dimensional constitutive equations are derived with three-dimensional hierarchical shape functions expanded from one-dimensional Lobatto functions. Transfinite mapping technique is used to represent a circular boundary. The present model provides accuracy and simplicity in terms of stress concentration factor, stress distribution, the number of degrees of freedom, and non-dimensional stress intensity factor as compared with previous works in literatures. Stress intensity factors obtained by the three-dimensional virtual crack closure technique are estimated with respect to the variation of width of finite plate, radius of notch root, angular inclination of V-shaped notch, and crack length.

• The korean journal of orthodontics
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• v.46 no.4
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• pp.212-219
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• 2016

Objective: The purpose of this study was to evaluate treatment effects after distalization of the mandibular dentition using ramal plates through lateral cephalograms. Methods: Pre- and post-treatment lateral cephalograms and dental casts of 22 adult patients (11 males and 11 females; mean age, $23.9{\pm}5.52years$) who received ramal plates for mandibular molar distalization were analyzed. The treatment effects and amount of distalization of the mandibular molars were calculated and tested for statistical significance. The significance level was set at p < 0.001. Results: The mandibular first molar distalization at the crown and root were 2.10 mm (p < 0.001) and 0.81 mm (p = 0.011), respectively. In the evaluation of skeletal variables, there was a significant increase in the Wits appraisal (p < 0.001). In the evaluation of the soft tissue, there was no significant effect on upper lip position, but the lower lips showed a significant retraction of 2.2 mm (p < 0.001). Conclusions: The mandibular molars showed a significant amount of distalization accompanied by limited extrusion and mesiobuccal rotation of the crowns. A ramal plate may be a viable device for mandibular total arch distalization in Class III patients who are reluctant to undergo orthognathic surgery.

• PNF and Movement
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• v.15 no.3
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• pp.259-266
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• 2017

Purpose: This study aimed to compare muscle activities in the right leg during squatting on an angle-adjustable inclined wooden plate at three different angles. Methods: The subjects were 19 healthy adult men and women. An angle-adjustable inclined wooden plate was used for the experiment, and the subjects performed squatting at three adjusted angles of $0^{\circ}$ ankle angle, $10^{\circ}$ ankle flexion, and $10^{\circ}$ plantar flexion. Squatting was randomly performed without a sequence. The knee angle was set at $45^{\circ}$, and a goniometer was used to measure the angles accurately. Electromyography was employed to measure and compare muscle activity in the right leg in each condition. The measured data were converted to root mean square values to calculate the muscle activities. Results: This study showed no statistically significant difference at a $0^{\circ}$ ankle angle, but a statistically significant difference was found in the vastus medialis at $10^{\circ}$ of ankle flexion. Moreover, statistically significant differences were observed in the vastus medialis and lateralis at $10^{\circ}$ of plantar flexion. Conclusion: This study showed a statistically significant difference in the vastus medialis at $10^{\circ}$ of ankle flexion and statistically significant differences in the vastus medialis and lateralis at $10^{\circ}$ of plantar flexion. Therefore, it may be effective to perform squatting at $10^{\circ}$ of ankle flexion when intending to selectively strengthen the vastus medialis and at $10^{\circ}$ of plantar flexion when intending to strengthen both the vastus medialis and lateralis.

• Korean Journal Plant Pathology
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• v.3 no.3
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• pp.203-209
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• 1987

The substances obtained from the leaf, stem and root of tobacco plants inoculated with avirulent and virulent isolates of Pseudomonas solanacearum were at R_f\;0.6$ and R_f\;0.9$ on TLC plate, respectively. Both substances showed antibacterial activities not only on P. solanacearum but also on Erwinia carotovora subsp. carotovora and Escherichia coli in vitro. However, the antibacterial substances were not detectable from the filtrate of the autoclaves tobacco sap medium, in which the avirulent or virulent bacterium was cultured for 3 days. Peroxidase and poly phenoloxidase activities and their isozyme patterns did not differ significantly between plants treated with the virulent and avirulent isolates, or between the susceptible cultivar BY 4 and the resistant cultivar NC 82. However, activities of the two enzymes were increased in leaves of the susceptible cultivar BY 4 treated with either the virulent or the avirulent isolate.