• Restorative Dentistry and Endodontics
• /
• v.33 no.3
• /
• pp.204-212
• /
• 2008

The purpose of this study was to compare the apical microleakage in root canal filled with Resilon by methacrylate-based root canal sealer or 2 different self-adhesive resin cements. Seventy single-rooted extracted human teeth were sectioned at the CEJ perpendicular to the long axis of the roots with diamond disk. Canal preparation was performed with crown-down technique using Profile NiTi rotary instruments and GG drill. Each canal was prepared to ISO size 40, .04 taper and 1 mm short from the apex. The prepared roots were randomly divided into 4 experimental groups of 15 roots each and 5 roots each for positive and negative control group. The root canals were filled by lateral condensation as follows. Group 1: Guttapercha with AH-26, Group 2: Resilon with RealSeal primer & sealer, Group 3: Resilon with Rely-X Unicem, Group 4: Resilon with BisCem. After stored in $37{\circ}C$, 100% humidity chamber for 7 days, the roots were coated with 2 layers of nail varnish except apical 3 mm. The roots were then immersed in 1% methylene blue dye for 7 days. Apical microleakage was measured by a maximum length of linear dye penetration after roots were separated longitudinally. One way ANOVA and Scheffe's post-hoc test were performed for statistical analysis. Group 1 showed the least apical leakage and there was no statistical significance between Group 2, 3, 4. According to the results, the self adhesive resin cement is possible to use as sealer instead of primer & sealant when root canal filled by Resilon.

• Journal of Bio-Environment Control
• /
• v.27 no.4
• /
• pp.381-390
• /
• 2018

This study was conducted to examine the growth characteristics of seedlings of several major fruit vegetables and compare them between plants grown with the conventional plug seedling system (Plug) and those grown with the cylindrical paper pot system (CPP). There were no significant differences in shoot growth characteristics, such as plant height, leaf area, dry weight, and fresh weight, between tomato, cucumber, and watermelon plants grown with the CPP and Plug systems. The total root lengths of tomato and cucumber plants grown with Plug were longer than those grown with CPP at the beginning of seedling growth, and the total root lengths of watermelon grown with Plug were longer than those grown with CPP throughout the whole seedling period. The length of root that separated five steps according to the diameter of the root of tomato did not differ between CPP and Plug, but those of cucumber and watermelon were 20-251% longer with Plug than with CPP for all kinds of roots. The fresh weight of Plug-grown tomato roots was about 30% heavier than that of CPP-grown tomato during the seedling period, but the difference decreased as growth progressed. Finally, there was no difference between plants before and after transplanting. The fresh weights of the Plug-grown plants were about 20-30% heavier than those of CPP-grown ones in terms of the whole seedling. After transplanting to the Wagner pot, the shoot growth of Plug-grown watermelon plants in terms of dry weight was low until 7 days had passed. However, this tendency was reversed from 8 days after transplantation onward. In conclusion, there were no significance differences in the growth of shoots between plants grown with the CPP and Plug systems. However, root development was better with Plug than with CPP.

• Restorative Dentistry and Endodontics
• /
• v.22 no.1
• /
• pp.413-427
• /
• 1997

Porphyromonas endodontalis and Prevotella intermedia are black-pigmented anaerobic gram negative rods which have been isolated from infected root canals and submucous abscesses of endodontic origin. And they are associated with clinical symptoms such as pain, percussion, and foul odor. It has been reported that there are 3 serotypes according to capsule membrane in P. endodontalis and 2 DNA homology groups and 3 serotypes in P. intermedia, but there is no data available regarding genetic diversity for the species P. endodontalis and P. intermedia. The purpose of this study is to investigate genetic diversities between individual strains of P. endodontalis and P. intermedia which are indistinguishable by serotyping and biotyping using bacterial DNA restriction endonuclease analysis. 45 teeth with at least one clinical symptoms, with single canal, and with pulp necrosis were sampled. For sampling bacteria, access cavity was prepared after disinfecting tooth and its surroundings. Then the paper point was inserted to the apex of the canal, leave there for 15 seconds, and finally it was placed into PRAS Ringer's solution and PBS solution. P. endodontalis and P. intermedia were identified by biochemical test and IIF after subculturing black and brown colonies which were produced after 7 days of incubation on BAP in anaerobic chamber. P. endodontalis and P. intermedia strains were grown in BHI broth and whole genomic DNA was extracted by phenol-chloroform extraction technique and digested by restriction endonuclease, Eco RI and Pst I. The resulting DNA fragments were separated by agarose gel electrophoresis, stained with EtBr and photographed under UV light. The results were as follows : 1. In both P. endodontalis and P. intermedia, different serotypes could be found within a root canal of same patient. 2. There were obvious genetic heterogeneity within a patient and within a serotype in both P. endodontalis and P. intermedia. 3. P. endodontalis serotype c, isolated from different patients, exhibited limited genotypic diversity.

• Korean Journal of Agricultural Science
• /
• v.17 no.1
• /
• pp.52-64
• /
• 1990

As a search for natural antioxidants, antioxdative fractions in Pueraria roots were extracted, identified using column chromatography, thin layer chromatography or high performance liquid chromatography. The components which have most effective antioxidative activities were further identified by IR and GC-MS. Separated antioxidative components were then added to four different oils to examine their antioxidative activities. Yield of extract obtained from pueraria root powder by solvent extraction using four step solvent systems was 2.54%. Antioxidative activity of the extracts was as effective as that of 100 ppm ${\delta}$-tocopherol addition, when 0.1% of the extracts was added to linoleic acid. The strongest antioxidative component of methanol extract of pueraria root was identified as puerarin. Aunioxidative activity of puerarin on lard was more effective than ${\alpha}$-tocopherol, but less effective than ${\delta}$-tocopherol. When the puerarin was added to edible oil and heat treated at $145^{\circ}C$, the acid value was lowest in lard and was highest in soybean oil. Antioxidative activity in terms of carbonyl value, thiobarbituric acid value and anisidine value was most high in palm oil and least in soybean and cottonseed oil.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.27 no.3
• /
• pp.383-387
• /
• 2000

Fusion is defined as union of two separate tooth buds at some stage in their development with confluence of dentin and characterized by separate root canal and large single crown, while gemination is defined as an attempt of the single tooth bud to incompletely divide and usually result in a single root with one root canal and two completely or incompletely separated crowns. It is sometimes difficult to decide whether an abnormally large tooth is the result of fusion of a normal and a supernumerary tooth, or of gemination; use of the term 'Double tooth' may make the clinicians avoid this difficulty(Brook & Winter). Commonly there are no symptoms, but the problems associated with these anomalies include esthetics, possible loss of arch length and delayed or ectopic eruption of the permanent teeth, caries along the line of demarcation, and periodontal disease. Commonly, it dose not need to be treated in primary dentition but in case of permanent dentition, it may be requested to be treated due to esthetics and other problems. In our case, a 8 years old girl showed a Double tooth, we attained the favorable results by performing hemisection with apexification.

• Imaging Science in Dentistry
• /
• v.53 no.1
• /
• pp.11-19
• /
• 2023

Purpose: This study compared the accuracy of detection of incomplete vertical root fractures (VRFs) in filled and unfilled teeth on cone-beam computed tomography images with and without a metal artefact reduction (MAR) algorithm. Materials and Methods: Forty single-rooted maxillary premolars were selected and, after endodontic instrumentation, were categorized as unfilled teeth without fractures, filled teeth without fractures, unfilled teeth with fractures, or filled teeth with fractures. Each VRF was artificially created and confirmed by operative microscopy. The teeth were randomly arranged, and images were acquired with and without the MAR algorithm. The images were evaluated with OnDemand software (Cybermed Inc., Seoul, Korea). After training, 2 blinded observers each assessed the images for the presence and absence of VRFs 2 times separated by a 1-week interval. P-values<0.05 were considered to indicate significance. Results: Of the 4 protocols, unfilled teeth analysed with the MAR algorithm had the highest accuracy of incomplete VRF diagnosis (0.65), while unfilled teeth reviewed without MAR were associated with the least accurate diagnosis (0.55). With MAR, an unfilled tooth with an incomplete VRF was 4 times more likely to be identified as having an incomplete VRF than an unfilled tooth without this condition, while without MAR, an unfilled tooth with an incomplete VRF was 2.28 times more likely to be identified as having an incomplete VRF than an unfilled tooth without this condition. Conclusion: The use of the MAR algorithm increased the diagnostic accuracy in the detection of incomplete VRF on images of unfilled teeth.

• Applied Biological Chemistry
• /
• v.46 no.4
• /
• pp.380-384
• /
• 2003

Optimal extraction, separation and capillary rinsing conditions for capillary electrophoresis (CE) were established to discriminate the geographical origin of ligusticum root (Ligusticum wallichii) using 113 samples (domestic sample n = 62, foreign sample n = 51). Ligusticum root was extracted with 30% ethanol and separated on a uncoated fused-silica $(50\;{\mu}m{\times}27\;cm)$ capillary. Conditions for optimal analysis include: temperature, $40^{\circ}C$; voltage, 10 kV; and pressure injection time, domestic and foreign samples were 5 sec and 2 sec, respectively. The optimal separation buffer was 0.1 M phosphate buffer (pH 2.5) containing 15 mM iminodiacetic acid with 40% methanol. Under the optimal conditions established for CE, the ratio of specific peak area (peak LW-1) to other peak area (peak LW-5) was effective in discrimination geographical origin of ligusticum root. The mean accuracy for correct discrimination of geographical origin of domestic and foreign ligusticum roots were 65% and 63%, respectively.

• Proceedings of the KACD Conference
• /
• 2001.05a
• /
• pp.247-251
• /
• 2001

;A dental developmental anomaly is defined as an isolated aberration in tooth form, caused by a disturbance or abnormality which occurred during tooth development. There are numerous types of dental anomalies, and a considerable variation in the extent of the defects occurs with each type. Teeth with these anomalies pose unique challenges. Since the defects are not always apparent clinically, they can confuse diagnosticians investigating the etiology of pulpal pathosis. When endodontic treatment is required, the defects often hinder access cavity preparation and canal instrumentation. Treatment planning also becomes more challenging, since the defects can create complicated periodontal problems, and the malformed teeth can be difficult to restore, particularly those weakened by endodontic therapy. Fusion is defined as the joining of two developing tooth germs resulting in a single large tooth structure. The incidence of fusion is < 1% in the Caucasian population, and it is believed that physical force or pressure produces contact of the developing teeth. Clinically and radiographically, a fused tooth usually appears as one large crown with at least partially separated roots and root canals. There may be a vertical groove in the tooth crown delineating the originally separate crowns. Dens invaginatus is a deep surface invagination of the crown or root that is lined by enamel. Teeth in both maxillary and mandibular arches may be affected, but the permanent maxillary lateral incisor is the tooth most commonly involved. Studies have revealed an incidence ranging from 0.25% to as high as 10%. The invagination ranges from a slight pitting to an anomaly occupying most of the crown and root. The invagination frequently communicates with the oral cavity, allowing the entry of irritants and microorganism either directly into pulpal tissues or into an area that is deparated from pulpal tissues by only a thin layer of enamel and dentin. This continuous ingress of irritants and the subsequent inflammation usually lead to necrosis of the adjacent pulp tissue and then to periapical or periodontal abscesses. If the invagination extends from the crown to the periradicular tissue and has no communication with the root canal system, the pulp may remain vital. Recommended treatment of fused tooth and dens invaginatus has been reported in the endodontic literature. This case report describes the endodontic treatment of a maxillary laterl incisors having fused crown and dens invaginatus.natus.

• Journal of Plant Biology
• /
• v.14 no.4
• /
• pp.14-18
• /
• 1971

Lilium Miquelianum Makino is a species which originated in Korea. The Karyotype of the species was examined in materials collected at Mts. Kaya, Kasan, Chejung, and Kaji. The results are as follows: 1) The somatic chromosome number was found to be 2n=24. 2) The karyotype is described as: K=2Am＋2Bkm＋2Csst＋2Dsst＋2Ests＋2Fst＋2Gst＋2Hst＋2Ist＋2Jsst＋2Kst＋2Lst m: metacentric, sm: submetacentric st: subtelocentric, s: secondary constriction 3) A single subcentric supernumerary B-chromosome was found in some bulbs from Mt. Kasan. 4) The shape of the supernumerary B-chromosome was similar to that of the E chromosome which had separated at its secondary constriction and lost its lower chromosome fragment. 5) From three to eight nucleio of varying sizes were found in the telophase or interphase nucleus of root tip cells. The maximum number of eight nucleoli corresponds to the number of chromosomes that have a secondary constriction.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.12 no.4
• /
• pp.253-259
• /
• 1992

The esterase isozyme in tissue of wild legume plants were separated by horizontal starch gel electrophoresis. Extracts used in this study were prepared from fully expanded young leaf, cotyledon and radicle of seedling and root-nodule of Glycine sola, Vigna vexillata var. tsuscmensis and Trifoliwn repens. The results are as follows; 1. Each tissue examined had a characteristic banding pattcrn. Number of bands in each species, G. soja, V. vexillata, and T . repens, were 14, 8 and 1 1 bands, respectively. And difference in esterase isozyme bands were greater from tissue to tissue than difference between habitat. 2. Est-I, Est-2. Est-3 and Est-4 in G. soja, Est-I in V. vexillata and Est-l and Est-2 in T. repens showed strong cnzyme activity than other enzyme. 3. Esterase isozyme variation in G. soja and T . repens showed more variety than V. vexillata. This is resulted from many genotypic differences within species. 4. The main enLyme among thc esterase isozyme were Est-I. Est-2, Est-3 and Est-4.