Effects of Soy Isoflavone Intake on Nitrite Content and Antioxidant Enzyme Activities in Male Rats Fed High-Fat Diet

This study was performed to investigate the effect of soy isoflavone on plasma nitrite concentration and the antioxidant enzyme activities of erythrocyte and the liver using adult male rats fed high fat diet. Seven-week old male Sprague Dawley rats were divided into three groups and fed high fat diet (15% beef tallow, 1% cholesterol; control: IF0) or high fat diets containing isoflavone 80 ppm (IF80) or 320 ppm (IF320) for 10 weeks. Plasma nitrite concentration as a vasodilator, and antioxidant enzyme activities in erythrocytes and the liver were measured. Plasma nitrite concentration was increased by 45% and 35%, respectively, in IF80 and IF320 than in IF0 group. Erythrocyte catalase, glutathione peroxidase (GPx) and glutathione reductase (GR) activities increased by 31%, 30% and 40% in IF320 compared to IF0 group. Especially, erythrocyte GR activity increased by 61% in IF80 group. However, catalase activity in the liver was decreased in IF80 group. GPx and GR activities in the liver were not differ among groups. The results suggest that soy isoflavone have the protective effect against risk factors related with cardiovascular disease by improving vasodilator factor, nitrite, and antioxidant enzyme activities in blood.

Influence of plugger penetration depth on the apical extrusion of root canal sealer in continuous wave of condensation technique / 대한치과보존학회지

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.

Shaping ability of four rotary nickel-titanium instruments to prepare root canal at danger zone / 대한치과보존학회지

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). 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.

Microleakage at the cervical margin of Class II composite restorations with different intermediate layer treatments / 대한치과보존학회지

No abstract available.

Analysis of papers published in the journal of korean academy of conservative dentistry during the last ten years / 대한치과보존학회지

To understand the recent characteristics of the papers published in the Journal of Korean Academy of Conservative Dentistry(JKACD), All the papers in the JKACD of 1992 to 2001 were analyzed. A total of 513 papers were classified according to its type, field and subject of the study, school and the number of authors, references, and written language. The results were as follows; 1. According to the type of the paper, 506(98.6%) were original articles, 3(0.6%) were review articles, and 4(0.8%) were case reports. 2. Anual proportion of papers in the field of operative dentistry was similar to that of endodontics. 3. In the field of operative dentistry, esthetic restorative materials and bonding to tooth constituted major subjects of the studies. In the field of endodotics, pulp biology was prominent and canal shaping, endodontic microbiology and canal obturation were steadily reported. 4. According to author's school, similar number of papers were published in the field of operative dentistry and endodontics in general. However, some schools showed preponderances. 5. Most studies were done by two or more authors. Studies published by two authors were most. 6. Fifty(9.7%) papers were done in collaboration with workers of the other field. 7. Average number of references cited in the papers was 41.2, including domestic references of 1.8. 40.7% of the papers was shown to cite no domestic papers at all. 8. Twenty-eight(5.5%) papers were written in English, with increasing ratio.