1.THREE-DIMENSIONAL COMPARISON OF FRAMEWORK DISPLACEMENTS JOINED BY VARIOUS CONNECTION TECHNIQUES.
Jang Seop LIM ; Young Chan JEON ; Chang Mo JEONG
The Journal of Korean Academy of Prosthodontics 1999;37(3):358-374
This study measured the relative displacements of the five-unit fixed partial dentures as cast with the same fixed partial dentures sectioned and assembled by investment-soldering, soldering stand-soldering, and cast-joining techniques. A total of fifteen specimens using a type IV gold alloy wee one-piece cast as control and then sectioned and assembled five test specimens for each method were prepared. A computerized three dimensional coordinate measuring machine and specially designed cylinder for this study were used. Displacement was defined by six displacement variables for the each of cylinders incorporated in each casting: three component displacements ( Lx, Ly, and Lz) and rotational displacements( thetax, thetay, thetaz). The global displacement was computed using the mathematical formula R= Global displacement ={{{{rm SQRT { (x'-x)^2 +(y'-y)^2 + (z'-z)^2} }} }} Under the conditions of this study, the following conclusions were drawn: 1. The investment-soldering group showed the largest mean value of final global displacements, followed by stand-soldering group, cast-joining group and one-piece cast group. However, between the mean values of final global displacement for the cast-joining group and one-piece cast group, there was no significant difference. 2. For investment-soldering and stand-soldering groups, the greater global displacements were recorded in soldering phase than in indexing or investing phase. 3. For one-piece cast group, the displacements occured mostly in the casting phase. And for castjoining group, there was no significant difference in global displacements among the fabrication procedures. 4. Intercentroidal distance decreased in framework-pattering, solder-indexing, solder-standing, and soldering phases, but increased in investment block-investing and casting phases. 5. Specially designed cylinder for touch-trigger type coordinate measuring machine was validated.
Abstracting and Indexing as Topic
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Alloys
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Denture, Partial, Fixed
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Investments
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Methods
2.Research progress on the role of miRNAs in amphetamine-type stimulants addiction
Mingjin JIANG ; Chan LI ; Yingbo LIN ; Daoqi ZHU ; Zhixian MO
Chinese Pharmacological Bulletin 2015;(10):1352-1355
Amphetamine-type stimulants ( ATS ) , a group of new-type synthetic drugs mainly in psychological dependence, are abused more and more severely in recent years. MicroRNAs ( MiRNAs ) are an important class of endogenous non-coding small RNAs that mediate posttranscriptional negatively regulation of gene expression by targeting specific mRNA sequences to in-hibit the translation of mRNAs or degrade the expression of mR-NAs. ATS can induce the changes in the expression of miRNAs in addiction-related brain regions which directly involve in the regulation of ATS-induced addictive behaviors. Therefore, to study the regulatory role of miRNAs in ATS-induced addiction has important implications for dependent mechanisms of new-type drugs and the discovery of the new targets of drug actions.
3.Postoperative Pain Control by Ultrasound-Guided Sciatic Nerve Catheterization: A Technical Note.
Chan KANG ; Deuk Soo HWANG ; Young Mo KIM ; Jung Mo HWANG ; Seung Hyun LEE
Journal of Korean Foot and Ankle Society 2011;15(2):97-101
Intravenous Patient Controlled Analgesia (IV PCA) after general or spinal anesthesia may be a method of postoperative pain control, but side effects such as nausea, vomiting, and sedation occurs in most patients. The following research is based on the ultrasound guided femorosciatic nerve block held on parts below the knee joint operation. Because this anesthesia is held locally on the sciatic nerve with continuous anesthesia performed through perineural catheterization, the complications of nausea, vomiting, and sedation may be reduced while postoperative pain caused by the sciatic nerve is controlled. The following report is held on this experience.
Analgesia, Patient-Controlled
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Anesthesia
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Anesthesia, Spinal
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Catheterization
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Catheters
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Humans
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Knee Joint
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Nausea
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Nerve Block
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Pain, Postoperative
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Sciatic Nerve
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Vomiting
4.MARGINAL DISCREPANCY AND RETENTION FORCE OF CONICAL TELESCOPE OUTER CROWN WITH CO-CR-TI ALLOY.
Hi Chan JUNG ; Chang Mo JEONG ; Young Chan JEON ; Jang Seop LIM
The Journal of Korean Academy of Prosthodontics 2000;38(2):214-225
The purpose of this study was to investigate the effects of investing conditions on the marginal discrepancy of conical telescope outer crown with Co-Cr-Ti alloy(Dentitan) and to compare the marginal discrepancy and the retention force of outer crowns using different pattern materials (plastic foil, casting wax, pattern resin). To evaluate the effects of investing conditions on the marginal discrepancy, patterns with plastic foil were invested under three different liquid/powder ratio conditions using phosphate bonded investment (Univest-nonprecious): standard, 10% decreased and 10% increased. At each liquid/powder ratio condition, metal ring was lined with single or double layers of ceramic ring liner. The marginal discrepancy of outer crown at different investing conditions was measured by x 100 compact measuring microscope(STM5, Olympus, Japan). For measurement of the marginal discrepancy and the retention force of outer crown using different pattern materials, the investing condition of 10% decreased liquid/powder ratio and double layers of ring liner was selected because this investing condition resulted in the best fit of outer crown. Marginal discrepancy was measured in the same way above and retention force on universal testing machine. Under the conditions of this study, the following conclusions were drawn: 1. The thickness of ring liner had more influence on the marginal discrepancy of outer crown than the liquid/powder ratio, and the acceptable marginal fitness could not be expected at the investing condition directed by investment manufacturer. 2. There were no differences in the marginal discrepancy of outer crown among three different pattern materials 00.05). 3. Casting wax showed the greatest retention force(1640g) of outer crown, followed by pattern resin(1110g), plastic foil(820g). However, there was no significant difference between plastic foil and pattern resin(p>0.05). 4. Plastic foil showed the least variation in marginal discrepancy and retention force.
Alloys*
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Ceramics
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Crowns*
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Investments
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Plastics
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Telescopes*
5.Case of Decreased Serum Valproic Acid Concentration During Concomitant Use of Meropenem in Patients with Traumatic Brain Injury
Chan-Kyu JEONG ; Chan-Mo YANG ; Sang-Yeol LEE ; Seung-Ho JANG
Mood and Emotion 2022;20(3):65-67
Blood valproic acid levels were decreased in patients with traumatic brain injury who had been using valproic acid to control irritability and aggression, and the symptoms worsened coincident with the administration of meropenem, a carbapenem-based antibiotic. Two weeks after the discontinuation of meropenem, valproic acid levels were restored to an effective therapeutic concentration. Therefore, when valproic acid and carbapenem-based antibiotics are used together, blood valproic acid levels may decrease due to drug interaction, and irritability symptoms may worsen. Thus, close monitoring of serum valproic acid levels is required.
6.Surgical Outcomes of Implantation of Newly Designed T-shaped Intraocular Lens in Congenital Cataract.
Jun Mo LEE ; Chan Yun KIM ; Hye Sun CHOI ; Seung Jeong LIM
Journal of the Korean Ophthalmological Society 2002;43(8):1423-1428
PURPOSE: We evaluated the surgical outcomes and complications of new pediatric intraocular lens in congenital cataract. METHODS: A retrospective study was carried out on 29 eyes of 22 patients diagnosed with congenital cataract that underwent optic capture following lens emulsification. New pediatric intraocular lens (LJC 575A, Lucid Korea, Seoul, Korea) implantation into the bag was performed with posterior capsulorrhexis and anterior vitrectomy. RESULTS: After follow-up of 17.79+/-7.08 months, 15 eyes showed a visual acuity of 0.5 or above, and 10 (71.4%) of the 14 eyes showed a visual acuity of 20/470 or above. As for complications, posterior synechia developed in 8 eyes, exudative membrane was found in 3 eyes, iris capture by IOL haptic was found in 1 eye, and slight opacification of posterior capsule was identified in 1 eye. CONCLUSIONS: Use of new 8 mm pediatric intraocular lens in congenital cataract may be considered selectively.
Capsulorhexis
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Cataract*
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Follow-Up Studies
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Humans
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Iris
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Korea
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Lenses, Intraocular*
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Membranes
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Retrospective Studies
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Seoul
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Visual Acuity
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Vitrectomy
7.COLORIMETRIC ANALYSIS OF COLOR DIFFERENCES BETWEEN DENTIN PORCELAINS.
Chang Seop KIM ; Jang Seop LIM ; Chang Mo JEONG ; Young Chan JEON
The Journal of Korean Academy of Prosthodontics 1999;37(4):425-432
The purpose of this study is to evaluate the color differences that can exist between differnet brands of dentin porcelain having identical shade designations. The instrumental colorimetric technique was used to determine these differences. The three brands of dentin porcelain used were Vita VMK-68, Shofu Vintage, and Ceramco II. The three shades selected were the Vita Lumin shades A2, B2, and C2. The color difference values were compared with each other using L*, a*, b*, three variables of the CIELAB color system, and E. The results of this study were as follows: 1. Corresponding shades of different brands of dentin porcelain produced different L*, a*, b* values. 2. The greatest E value in corresponding shade was found to exist between Ceramco II and Shofu Vintage, followed by between Vita VMK-68 and Ceramco II, and then between Vita VMK-68 and Shofu Vintage. 3. The E values in shade C2 were mainly influenced by L* value ; however none of L*, a*, b* values had greater influence on E values than the others in shade A2, B2. 4. Shofu Vintage had the highest b* value, followed by Vita VMK-68, and then Ceramco II.
Dental Porcelain*
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Dentin*
8.A MEASUREMENT OF DISPLACEMENTS OF CAST FRAMEWORK BY TORCH SOLDERING AND ELECTRIC SOLDERING TECHNIQUES.
Sang Won JEON ; Jang Seop LIM ; Chang Mo JEONG ; Young Chan JEON
The Journal of Korean Academy of Prosthodontics 1999;37(6):791-799
The purpose of this study was to investigate the displacements of cast framework by torch soldering and electric soldering techniques. Specimen had two cylinders and connecting bar that had sectioned with 0.3mm gap at mid point. 10 of total specimens were divided into two groups. In torch soldered group, soldering investment block was made and conventional torch soldering procedure was carried out. In electric soldered group, electric soldering was carried out on the master cast without soldering investment block by using electric soldering machine(Dentapunkt DP 7, Kulzer, Germany). After soldering procedure, three dimensional coordinates of two centroids of each cylinder were measured by three dimensional coordinate measuring machine. The intercentroidal displacement and global displacement were calculated and then, these values were compared and evaluated. The results were obtained as follows: 1. Intercentroidal distances of specimens decreased after both soldering procedures, and the decrease in intercentroidal distance was greater for torch soldered group than for electric soldered group 2. Global displacements of torch soldered group were greater than those of electric soldered group
Investments
9.THE INFLUENCE OF WATTAGE AND CURING TIME OF MICROWAVE ENERGY ON PHYSICAL PROPERTIES OF THE DENTURE BASE RESIN.
Dae Sung JEONG ; Jang Seop LIM ; Chang Mo JEONG ; Young Chan JEON
The Journal of Korean Academy of Prosthodontics 1999;37(6):767-775
The purpose of this study was to evaluate the effect of wattage and curing time on surface hardness, three-point bending strength and internal porosity of microwave curing denture base resin. Two sizes of resin spicimens were made of Acron MC ; 3.5x10x60mm for surface hardness and three-point bending strength measurement and 5x12x60mm for internal porosity measurement. They were cured by microwave energy at varing wattages(500W, 700W) and curing times(2min., 3min., 4min.) to determine if a certain wattage/curing time combination would improve physical properties. Surface hardness was measured with Vikers hardness tester, three-point bend-ing strength with universal testing machine and internal porosity was calculated by measuring the weight in air and in water. The results obtained were as follows : 1. There was no significant difference in percent porosity among experimental groups(p>0.05). 2. 500W/3min, group showed the higher surface hardness than 700W/2, 3, 4min. groups(p<0.05), and 700W/4 min. group showed the lower surface hardness than 500W/2, 3, 4min. groups(p<0.05), but there was no significant difference among others(p>0.05). 3. 500W/3min. group yielded the higher value of bending strength than 500W/2min., 700W/3, 4min. groups(p<0.05), but there was no significant difference among others(p>0.05).
Denture Bases*
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Dentures*
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Hardness
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Hardness Tests
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Microwaves*
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Polymethyl Methacrylate
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Porosity
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Water
10.A STUDY FOR SETTING AND THERMAL EXPANSION OF DENTAL SOLDERING INVESTMENTS.
Sung Ae SHIN ; Jang Seop LIM ; Chang Mo JEONG ; Young Chan JEON
The Journal of Korean Academy of Prosthodontics 1999;37(6):730-740
The purpose of this study was to investigate setting and thermal expansion of dental soldering investments. In order to compare expansion rates and to investigate the effect of water/powder ratio on expansion, setting and thermal expansion of four dental soldering investments were measured under three different water/powder ratio conditions: standard, 20% decreased and 20% increased. Setting expansion of investments was measured by use of dialgauge method. Each measurement was started two minutes later from the beginning of spatulation and recorded every one minute for one hour. Thermal expansion of cylindrical test specimens, 10mm diameter, 50mm length, was recorded in a Thermodilatometer at heating rate of 10degrees C per minute from 25degrees C to 700degrees C. The results of this study were obtained as follows: 1. Setting expansion rates under the standard water/power ratio condition were 0.198% in Speed-E, 0.090% in Deguvest, 0.080% in CM and Hi-temp. Setting expansion of Speed-E was significantly different from those of CM, Deguvest and Hi-temp, and setting expansion of Deguvest was significantly different from those of CM and Hi-temp(p<.05). 2. Under the decreased water/powder ratio condition, there was significant increase in setting expansion of 4 dental soldering investments(p<.05). 3. There were no significant differences in setting expansions of investments except Hi-temp between standard and increased water/powder ratio condition(p<.05). 4. Thermal expansion rates under the standard water/powder ratio condition were 1.923% in Deguvest, 1.629% in Speed-E, 1.619% in Hi-temp and 1.580% in CM. No significant difference in thermal expansions under the standard water/powder ratio condition existed only between Speed-E and Hi-temp(p<.05). 5. Under the decreased water/powder ratio condition, there was significant increase in thermal expansion of CM and Deguvest but decrease in thermal expansion of Speed-E(p<.05). 6. Under the increased water/powder ratio condition, there was significant decrease in thermal expansion of CM, Deguvest and Speed-E but decrease in thermal expansion of Hi-temp(p<.05).
Dental Soldering*
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Heating
;
Hot Temperature
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Investments*