• Journal of Food Hygiene and Safety
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• v.23 no.3
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• pp.264-270
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• 2008

Phytic acid(PA) (Inositol hexaphosphate, $IP_6$) is a naturally occurring polyphosphorylated carbohydrate that is present in substantial amounts in almost all plants and mammalian cells. Recently PA has received much attention for its role in anticancer activity. In the present study, the preventive effects of PA on colon carcinogenesis were investigated. Six-week old Fisher 344 male rats were fed a AIN-93G purified diet and PA(0.5% or 2% PA in water) for 8 weeks. The animals received two ($1^{st}\;and\;2^{nd}$ week) injections of azoxymethane(AOM, 15 mg/kg b.w.) to induce colonic aberrant crypt foci(ACF). After sacrifice, the total numbers of aberrant crypts(AC) and ACF in colonic mucosa were examined after staining with methylene blue. Blood and serum were analyzed with a blood cell differential counter and an automatic serum analyzer. AOM induced the total numbers of $142.3{\pm}22.3$ ACF/colon and $336.6{\pm}55.1$ AC/colon. PA at the doses of 0.5 and 2% decreased the numbers of ACF and AC/colon in a dose-dependent manner. The numbers of ACF/colon and AC/colon by PA at the dose of 0.5% were $124.4{\pm}28.5\;and\;302.7{\pm}67.3$, respectively. PA at the dose of 2% significantly decreased the ACF and AC numbers to $109{\pm}18.1\;and\;254.8{\pm}50.6$, respectively(p<0.01). Especially, 2% PA significantly reduced the number of large ACF(${\geq}4$ AC/ACF) from $26.8{\pm}6.2$ ACF/colon to $15{\pm}6.7$ ACF/colon(p<0.01). Although some parameters in blood counts and serum chemistry were changed compared with the control, no specific toxicity was found. These findings suggest that phytic acid can be a chemopreventive agent for colon carcinogenesis resulting from inhibition of the development of ACF in the F344 rat.

• Journal of the korean academy of Pediatric Dentistry
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• v.35 no.4
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• pp.619-627
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• 2008

The objective of this study was to compare the microleakage of five adhesive systems in the enamel and dentin of permanent teeth. Class V cavity preparations with occlusal margins in enamel and gingival margins in dentin were prepared on both buccal and lingual surfaces of 25 extracted human molar teeth. The tested adhesives were: Adper Scotchbond Multi-purpose Plus Adhesive (SM), Adper Single bond 2 (SB), Clearfil SE Bond (SE), Adper Prompt L-Pop (PL) and G-Bond (GB). The results were as follows: 1. At the enamel margins, PL showed the highest leakage value(0.85), and others showed values of SB(0.55), GB(0.50), SM(0.35) and SE(0.25) in decreasing order. There were statistically significant differences in PL vs. SM and PL vs. SE(p<0.05). 2. At the dentin margins, GB showed the highest leakage value(2.10), and others showed values of SE(1.45), PL(1.40), SB(1.05), SM(0.70) in decreasing order. There were statistically significant differences in GB vs. SB and GB vs. SM(p<0.05). 3. Dentin margins showed high dye penetration rate than enamel margins in all material tested groups and there were statistically significant differences for SE, PL and GB.

• Journal of Dental Rehabilitation and Applied Science
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• v.28 no.3
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• pp.245-252
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• 2012

The purpose of this study was to evaluate the influence of glide path on canal centering ratio after instrumentation with different single file systems; WaveOne and Reciproc. Reciproc R25 (VDW), WaveOne Primary (Dentsply Maillefer) and PathFile #13, 16, 19 (Dentsply Maillefer) were used in this study. In no glide path groups, Reciproc files and WaveOne files used for canal preparation without glide path. In glide path groups, the PathFile were used before canal preparation. Methylene blue dye was introduced into the canal to obtain a clear pre-instrumentation image. Pre-instrumentation images and post-instrumentation images were scanned using Epson Perfection V700 Photo scanner (Epson, Nagano, Japan). Transparencies of post-instrumentation images were changed and superimposed on pre-instrumentation images using Adobe Photoshop CS 3 (Adobe Systems Incorporated, San Jose, CA, USA). The centering ratio was calculated for each instrumented canal using the following formula: CR=|X1-X2|/Y. It was statistically analyzed using two-way ANOVA at 95% confidential level. The centering ratio in glide path groups were significant less than it in no glide path groups at 3, 4, 5 and 6 mm level. Except 1 and 6 mm level, WaveOne groups had significant less centering ration than Reciproc groups. At 6 mm level, there was no significant difference between WaveOne and Reciproc. In the limitation of this study, creation of a previous glide path before reciprocating motion instrumentation in curved canal appears to be appropriate and WaveOne system can be used for preparation of curved canal without severe aberrations.

• The Journal of Korean Academy of Prosthodontics
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• v.47 no.1
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• pp.53-60
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• 2009

Statement of problem: At present, as the esthetic demands are on the increase, there are many ongoing studies for tooth-colored post and cores. Most of them are about fiber post and prefabricated zirconia post, but few about one-piece milled zirconia post and core using CAD/CAM (computer-aided design/computer-aided manufacturing) technique. Purpose: The objective of this study was to compare microleakage of endodontically treated teeth restored with three different tooth-colored post and cores. Material and methods: Extracted 27 human maxillary incisors were cut at the cementoenamel junction, and the teeth were endodontically treated. Teeth were divided into 3 groups (n=9); restored with fiber post and resin core, prefabricated zirconia post and heat-pressed ceramic core, and CAD/CAM milled zirconia post and core. After the preparation of post space, each post was cemented with dual-polymerized resin cement (Variolink II). Teeth were thermocycled for 1000 cycles between $5-55^{\circ}C$ and dyed in 2% methylene blue at $37^{\circ}C$ for 24 hours. Teeth were sectioned (bucco-lingual), kept the record of microleakage and then image-analyzed using a microscope and computer program. The data were analyzed by one-way ANOVA and Scheffe's multiple range test (${\alpha}=0.05$). Results: All groups showed microleakage and there were no significant differences among the groups (P>.05). Prefabricated zirconia post and heat-pressed ceramic core showed more leakage in dye penetration at the post-tooth margin, but there was little microleakage at the end of the post. Fiber post and resin core group and CAD/CAM milled zirconia post and core group indicated similar microleakage score in each stage. Conclusion: Prefabricated zirconia post and heat-pressed ceramic core group demonstrated better resistance to leakage, and fiber post and resin core group and CAD/CAM milled zirconia post and core group showed the similar patterns. The ANOVA test didn't indicate significant differences in microleakage among test groups. (P>.05)

• The Journal of Internal Korean Medicine
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• v.19 no.1
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• pp.409-427
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• 1998

Insamjungchuntang has been used in Korea for many centuries as a treatment for respiratory disease. The effect of Insamjungchuntang on tracheal smooth muscle is not known. The purpose of the present study is to determine the effect of Insamjungchuntang on histamine and acetylcholine induced tracheal smooth muscle contraction in rats and guinea pigs. Guinea pig (500 g, male) and Sprague Dawley rats (200 g, male) were killed by $CO_2$ exposure and a segment (8-10 mm) of the thoracic trachea from each rat and guinea pig was cut into equal segments and mounted 'in pairs' in a tissue bath. Contractile force was measured with force displacement transducers under 0.5 g loading tension. The dose of histamine (His) and acetylcholine (Ach) which evoked 50% of maximal response $(ED_{50})$ was obtained from cumulative dose response curves for histamine and acetylcholine$(10^{-7}{\sim}10^{-4}\;M)$. Contractions evoked by His ($ED_{50}$) and Ach $(ED_{50})$ were inhibited significantly by Insamjungchuntang. In guinea pig tracheal smooth muscle, the mean percent inhibition of acetylcholine induced contraction was $38.58\(p<0.05)\;after\;10{\mu}l/ml$ Insamjungchuntang, $90.75\(p<0.01)\;after\;30{\mu}l/ml$. Insamjungchuntang and $133.17\(p<0.01)\;after\;100{\mu}l/ml$ Insamjungchuntang. In rat tracheal smooth muscle, the mean percent inhibition of acetylcholine induced contraction was $10.0\(p<0.05)\;after\;10{\mu}l/ml$ Insamjungchuntang, $80.71\(p<0.01)\;after\;30{\mu}/ml$ Insamjungchuntang and $118.29\(p<0.01)\;after\;100{\mu}l/ml$ Insamjungchuntang. Also, in guinea pig tracheal smooth muscle, the mean percent inhibition of histamine induced contraction was $45.5\(p<0.01)\;after\;10{\mu}l/ml$ lnsamjungchuntang, and $93.17\(p<0.01)\;after\;30{\mu}l/ml$. lnsamjungchuntang $134.50\(p<0.01)\;after\;100{\mu}l/ml$ Insamjungchuntang. In rat tracheal smooth muscle, the mean percent inhibition of histamine induced contraction was $37.83\(p<0.01)\;after\;10{\mu}l/ml$ lnsamjungchuntang, $90.5\(p<0.01)\;after\;30{\mu}l/ml$ Insamjungchuntang and $135.17\(p<0.01)\;after\;100{\mu}l/ml$ Insamjungchuntang. Propranolol $(10^{-7}\;M)$ slightly but significantly attenuated the inhibitory effects of Insamjungchuntang. Following treatment with propranolol, the mean percent inhibition caused by $100{\mu}l/ml$. Insamjungchuntang fell to 46.42% in guinea pig induced by acetylcholine contraction and by $100{\mu}l/ml$ Insamjungchuntang fell to 5.43% (p<0.05) in rat induced by acetylcholine contraction and the mean percent inhibition caused by $100{\mu}l/ml$ Insamjungchuntang fell to 49.0% in guinea pig induced by histamine contraction and by $100{\mu}l/ml$ Insamjungchuntang fell to 48.6% (p<0.05) in rat induced by histamine contraction. Indomethacin and methylene blue $(10^{-7}\;M)$ did not significantly alter the inhibitory effect of lnsamjungchuntang. Also, I could find the effects of lnsamjungchuntang and Insamjungchuntanggamorphine on the tracheal smooth muscle in guinea pig and rat did not change significantly. These results indicate that Insamjungchuntang can relax histamine and acetylcholine-induced contraction of guinea pig and rat tracheal smooth muscle, and that this inhibition involves sympathetic effects.

• Journal of Oral Medicine and Pain
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• v.36 no.1
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• pp.1-10
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• 2011

The aims of this study were to establish the effect of gender and age on number of fungiform papillae and electrogustometric thresholds of the tongue, and to determine the relation between number of fungiform papillae and electrogustometric threshold. Sixty-two healthy subjects of 20 to 39 years old were enrolled in this study. Examination areas were defined as center, anterior, left lateral, right lateral, and posterior on the dorsal surface of the tongue, which was stained with methylene blue dye and photographed with a scale bar on it. The number of fungiform papillae within $1\; cm^2$ square area of each examination site was counted twice. The counted values were averaged to produce means. Taste thresholds were measured three times on each examination area using an electrogustometer. Means of the threshold values were calculated. 1. The number of fungiform papillae was the largest at the anterior examination area, followed by right lateral, left lateral, posterior and central. Women had more fungiform papillae than men at anterior, right lateral, and center areas. Subjects in twenties showed more fungiform papillae than those in thirties at anterior, right lateral, and left lateral areas. 2. Anterior area of the tongue measured the lowest electrogustometric threshold, followed by left lateral, right lateral, posterior and center. The threshold was higher in men at anterior and right lateral areas. The subjects in thirties had higher threshold only at right lateral area than those in twenties. 3. Electrogustometric threshold was inversely correlated with the number of fungiform papillae at anterior and posterior areas. The results showed that the number of fungiform papillae and taste threshold varied according to tongue locus, and they were influenced by age and gender. The results also suggested that the number of fungiform papillae was related to electrogustometric threshold inversely.

• Restorative Dentistry and Endodontics
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• v.35 no.3
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• pp.164-172
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• 2010

During a composite resin restoration, an anticipating contraction gap is usually tried to seal with low-viscosity resin after successive polishing, etching, rinsing and drying steps, which as a whole is called rebonding procedure. However, the gap might already have been filled with water or debris before applying the sealing resin. We hypothesized that microleakage would decrease if the rebonding agent was applied before the polishing step, i.e., immediately after curing composite resin. On the buccal and lingual surfaces of 35 extracted human molar teeth, class V cavities were prepared with the occlusal margin in enamel and the gingival margin in dentin. They were restored with a hybrid composite resin Z250 (3M ESPE, USA) using an adhesive AdperTM Single Bond 2 (3M ESPE). As rebonding agents, BisCover LV (Bisco, USA), ScotchBond Multi-Purpose adhesive (3M ESPE) and an experimental adhesive were applied on the restoration margins before polishing step or after successive polishing and etching steps. The infiltration depth of 2% methylene blue into the margin was measured using an optical stereomicroscope. The correlation between viscosity of rebonding agents and mciroleakage was also evaluated. There were no statistically significant differences in the microleakage within the rebonding procedures, within the rebonding agents, and within the margins. However, when the restorations were not rebonded, the microleakage at gingival margin was significantly higher than those groups rebonded with 3 agents (p < 0.05). The difference was not observed at the occlusal margin. No significant correlation was found between viscosity of rebonding agents and microleakage, except very weak correlation in case of rebonding after polishing and etching at gingival margin.

• Journal of Food Hygiene and Safety
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• v.25 no.3
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• pp.269-277
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• 2010

Selenium is an essential micronutrient for normal body function and functions as an essential constituent of selenoproteins. This study was carried out to investigate effect of selenium on the formation of colonic aberrant crypt foci (ACF) and tumor formation in a mouse model. Five-week old ICR mice were acclimated for one week and fed different selenium diet (0.02, 0.1, and 0.5 ppm) for 12 weeks. Animals received three intraperitoneal injections of azoxymethane (10 mg/kg B.W. in saline for 3 weeks), followed by 2% dextran sodium sulfate in the drinking water for a week. There were four experimental groups, including a normal control group and three different selenium levels groups. After sacrifice, the total numbers of aberrant crypt (AC) and ACF were measured in the colonic mucosa after methylene blue staining. The number of tumors was noted for tumor incidence. Liver selenium concentration was measured using ICP-AES method. Gutathione peroxidase (GPx) activity was determined using a GPx assay kit in the liver and colon. TUNEL assay and proliferating cell nuclear antigen (PCNA) staining were performed to examine the cell apoptosis and cell proliferation, respectively. Immunohistochemistry of $\beta$-catenin was also performed on the mucous membrane tissue of colon. The activity of GPx in the liver and colon was decreased in the selenium-deficient diet group while it was increased in the selenium-overloaded diet group. Apoptotic positive cells were increased in the selenium-overloaded diet group but decreased in the selenium-deficient diet group. PCNA staining area was decreased in the selenium-overloaded diet group. In addition, the $\beta$-catenin protein level in the selenium-deficient diet group was increased but decreased in the selenium-overloaded diet group. These results indicate that dietary selenium might exert a modulating effect on colon cancer by inhibiting the development of ACF and colon tumor formation in this mouse model.

• Restorative Dentistry and Endodontics
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• v.27 no.2
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• pp.142-149
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• 2002

Low-viscosity composite resins may produce better sealed margins than stiffer compositions (KempScholte and Davidson, 1988: Crim, 1989). Plowable composites have been recommended for use in Class V cavities but it is also controversial because of its high rates of shrinkage. On the other hand, in the study comparing elastic moduli and leakage, the microfill had the least leakage (Rundle et at. 1997) Furthermore, in the 1996 survey of the Reality Editorial Team, microfills were the clear choice for abfraction lesions. The purpose of this study was to evaluate the microleakage of 6 compostite resins (2 hybrids, 2 microfills, and 2 flowable composites) with and without load cycling. Notch-shaped Class V cavities were prepared on buccal surface of 180 extracted human upper premolars on cementum margin. The teeth were randomly divided into non-load cycling group (group 1) and load cycling group (group 2) of 90 teeth each. The experimental teeth of each group were randomly divided into 6 subgroups of 15 samples. All preparations were etched, and Single bond was applied. Preparations were restored with the following materials (n=15) : hybrid composite resin [Z250(3M Dental Products Inc. St. Paul, USA), Denfil(Vericom, Ahnyang, Korea)], microfill [Heliomolar RO(Vivadent, Schaan, Liechtenstein), Micronew(Bisco Inc. Schaumburg, IL, USA)], and flowable composite［AeliteFlo(Bisco Inc. Schaumburg, IL, USA), Revolution(Kerr Corp. Orange, CA, USA)]. Teeth of group 2 were subjected to occlusal load (100N for 50,000 cycles) using chewing simulator(MTS 858 Mini Bionix II system, MTS Systems Corp. Minn. USA). All samples were coated with nail polish 1mm short of the restoration, placed in 2％ methylene blue for 24 hours, and sectioned with a diamond wheel. Enamel and dentin/cementum margins were analyzed for microleakage on a sclale of 0 (no leakage) to 3 (3/3 of wall). Results were statistically analyzed by Kruscal-Wallis One way analysis, Mann-Whitney U-test, and Student-Newmann-Keuls method. (p = 0.05) Results : 1. There was significantly less microleage in enamel margins than dentinal margins of all groups (p＜0.05) 2. There was no significant between six composite resin in enamel margin of group 1. 3. In dentin margin of group 1, flowable composite had more microleakage than others but not of significant differences. 4. there was no significant difference between six composite resin in enamel margin of group 2. 5. In dentin margin of group 2, the microleakage were R＞A =H=M＞D＞Z. But there was no significant differences. 6. In enamel margins, load cycling did not affect the marginal microleakage in significant degree. 7. In enamel margins, load cycling did affect the marginal microleakage only in Revolution. (p＜0.05).

• Journal of dental hygiene science
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• v.13 no.3
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• pp.330-338
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• 2013

In order to explore microleakage in class V cavity based on different kinds of several dentin adhesive and composite resin, 2 kinds of composite resin was restored and exposed after applying 4 kinds of dentin adhesives. Deposited in methylene blue solution for 4 hours and cut in parallel with tooth longitudinal axis. By observing dye penetration level of enamel and dentin margins of each restored resin following conclusion was obtained. 1. In composite resin Filtek Z350XT Universal (3M/ESPE Dental Products, USA) in enamel margin, Easy Bond (3M/ESPE Dental Products) showed the lowest microleakage and this leakage was represented to be high in the order of Single Bond 2 (3M/ESPE Dental Products), Scotchbond Multi-Purpose (3M/ESPE Dental Products) and Cearfil SE Bond (Kuraray Medical Inc., Japan). In case of Filtek Z350XT Flowable (3M/ESPE Dental Products), Scotchbond Multi-Purpose showed the lowest microleakage and this leakage was represented to be high in the order of Single Bond 2, Clearfil SE Bond and Easy Bond. 2. In case of Filtek Z350XT Universal in dentin margin, Easy Bond showed the lowest microleakage and this leakage was represented to be high in the order of Scotchbond Multi-Purpose, Single Bond 2 and Clearfil SE Bond. In case of Filtek Z350XT Flowable, Scotchbond Multi-Purpose and Single Bond showed the lowest microleakage and this leakage was represented to be high in the order of Clearfil SE Bond and Easy Bond. 3. In all the groups excepting S-U group (Single Bond 2+Filtek Z350XT Universal), enamel margin showed more higher microleakage than that of dentin margin. 4. There was a difference between enamel and dentin margin among each group but it was not significant statistically (p>0.05). When summarizing this result, it is considered that composite resin and dentin adhesive could be applied selectively and particularly in case of applying 1-step self-etching dentin adhesive, this method would be advantageous for manipulation convenience and shortening of operation time.