1.The level of residual monomer in injection molded denture base materials.
Hyeok Jae LEE ; Chang Whe KIM ; Yung Soo KIM
The Journal of Korean Academy of Prosthodontics 2003;41(3):360-368
STATEMENT OF PROBLEM: The residual monomer of denture base materials causes hypersensitivity on oral mucosa and intereferes with the mechanical properties of the cured resin. The amount of residual monomer is influenced by materials, curing cycle, processing method, and etc. PURPOSE: The aim of this study was to investigate the residual methyl methacrylate(MMA) content of injection molded denture base polymer, and to compare this with the self-cured resin and the conventional compression molded heat-cured resin. MATERIALS AND METHODS: Disc shaped test specimens (50mm in diameter and 3mm thick) were prepared in a conventional flasking technique with gypsum molding. One autopolymerized denture base resins (Vertex SC. Dentimex. Netherlands) and two heat-cured denture base resins (Vertex RS. Dentimex. Netherlands, Ivocap. Ivoclar Vivadent, USA) were used. The three types of specimens were processed according to the manufacturer's instruction. After polymerization, all specimens were stored in the dark at room emperature for 7 days. There were 10 specimens in each of the test groups. 3-mm twist drills were used to obtain the resin samples and 650mg of the drilled sample were collected for each estimation. Gas chromatography (Agillent 6890 Plus Gas Chromatograph, Agillent Co, USA) was used to determine the residual MMA content of 10 test specimens of each three types of polymer. RESULTS: The residual monomer content of injection molded denture base resins was 1.057+/- 0.141%. The residual monomer content of injection molded denture base resins was higher than that of compression molded heat cured resin (0.867+/-0.169%). However, there was no statistical significant difference between two groups (p > 0.01). The level of residual monomer in self cured resin(3.675+/-0.791) was higher than those of injection molded and compression molded heat cured resins (p<0.01). CONCLUSION: With respect to ISO specification pass/fail test (2.2% mass fraction) of residual monomer, injection molding technique(1.057+/-0.141%) is a clinicaly useful and safe technique in terms of residual monomer.
Calcium Sulfate
;
Chromatography, Gas
;
Denture Bases*
;
Dentures*
;
Fungi*
;
Hot Temperature
;
Hypersensitivity
;
Mouth Mucosa
;
Netherlands
;
Polymerization
;
Polymers
2.Accuracy of a proposed implant impression technique using abutments and metal framework.
Hyeok Jae LEE ; Young Jun LIM ; Chang Whe KIM ; Jung Han CHOI ; Myung Joo KIM
The Journal of Advanced Prosthodontics 2010;2(1):25-31
PURPOSE: This study compared the accuracy of an abutment-framework (A-F) taken with open tray impression technique combining cementon crown abutments, a metal framework and resin cement to closed tray and resin-splinted open tray impression techniques for the 3-implant definitive casts. The effect of angulation on the accuracy of these 3 techniques was also evaluated. MATERIAL AND METHODS: Three definitive casts, each with 3 linearly positioned implant analogs at relative angulations 0, 30, and 40 degrees, were fabricated with passively fitted corresponding reference frameworks. Ten impressions were made and poured, using each of the 3 techniques on each of the 3 definitive casts. To record the vertical gap between reference frameworks and analogs in duplicate casts, a light microscope with image processing was used. Data were analyzed by two-way analysis of variance and the Tukey test. RESULTS: The open tray techniques showed significantly smaller vertical gaps compare to closed tray technique (P < .05). The closed tray and the resin-splinted open tray technique showed significantly different vertical gaps according to the angulation of implant (P < .05), but the A-F impression technique did not (P > .05). CONCLUSION: The accuracy of the A-F impression technique was superior to that of conventional techniques, and was not affected by the angulation of the implants.
Crowns
;
Light
;
Resin Cements
3.A case of sertoli - leydig cell tumor.
Jong Hyeok KIM ; Jin Hak KIM ; Yoon Seok CHANG ; Ghee Young CHOE ; Woo Ho KIM
Korean Journal of Obstetrics and Gynecology 1993;36(7):1704-1710
No abstract available.
Leydig Cell Tumor*
4.Complications of Traumatic Brain Injury: Post-traumatic Headache and Epilepsy.
Brain & Neurorehabilitation 2012;5(2):62-67
Posttraumatic headache (PTH) is one of several complications of traumatic brain injury (TBI). PTH usually resolving within the first 3 months, although a minority develop chronic headaches. PTH remains among the most controversial headache topics to its propensity for chronicity and often associated additional cognitive, behavioral, and somatic problems. Sufficient psychological or neurobiological markers for PTH do no exist, thus treatment can be very challenging and should always be multidisciplinary to make every reasonable effort in preventing the development of chronic pain. Posttraumatic seizure or epilepsy (PTE) is defined as a recurrent seizure disorder due to traumatic brain injury. PTE can be divided into three groups: immediate, early and late seizures. Immediate and early seizures are provoked seizures, whereas late seizure is unprovoked seizure. The effects of antiepileptic drugs (AED) in patients with TBI must be assessed separately in terms of prevention and control of provoked seizures and prevention of subsequent unprovoked seizures. Routine preventive AEDs are not indicated for patients with TBI and the effects are controversy.
Anticonvulsants
;
Brain
;
Brain Injuries
;
Chronic Pain
;
Epilepsy
;
Headache
;
Headache Disorders
;
Humans
;
Post-Traumatic Headache
;
Seizures
5.Recombination and Expression of VP1 Gene of Infectious Pancreatic Necrosis Virus DRT Strain in a Baculovirus,Hyphantria cunea Nuclear Polyhedrosis Virus.
Hyung Hoan LEE ; Jae Hyeok CHANG ; Hye Kyung CHUNG ; Sung Chul CHA
Journal of the Korean Society of Virology 1997;27(2):239-256
Expression of the cDNA of the VP1 gene on the genome RNA B segment of infectious pancreatic necrosis virus (IPNV) DRT strain in E. coli and a recombinant baculovirus were carried out. The VP1 gene in the peal-pol clone (Lee et al 1995) was cleaved with XbaI and transferred into baculovirus transfer vector, pBacPAK9 and it was named pBacVP1 clone. The VP1 gene in the pBacVP1 clone was double-digested with SacI and PstI and then inserted just behind 75 phage promoter and the 6x His region of the pQE-30 expression vector, and it was called pQEVP1. Again, the 6xHis-tagged VP1 DNA fragment in the pOEVPl was cleaved with EcoRl and transferred into the VP1 site of the pBacVPl, resulting pBacHis-VPl recombinant. The pBacHis-VP1 DNA was cotransfected with LacZ-Hyphantria cunea nuclear polyhedrosis virus (Lacz-HcNPV) DNA digested with Bsu361 onto S. frugiperda cells to make a recombinant virus. One VP1-gene inserted recombinant virus was selected by plaque assay, The recombinant virus was named VP1-HcNPV-1. The 6xHis-tagged VP1 protein produced by the pQEVPl was purified with Ni-NTA resin chromatography and analyzed by SDS-PAGE and Western blot analysis. The molecular weight of the VP1 protein was 94 kDa. The recombinant virus, VP1-HcNPV-1 did not form polyhedral inclusion bodies and expressed VP1 protein with 95 kDa in the infected S. frugiperda cells, which was detected by Western blot. The titer of the VP1-HcNPV-1 in the first infected cells was 2.0x10(5) pfu/ml at 7 days postinfection.
Bacteriophages
;
Baculoviridae
;
Blotting, Western
;
Chromatography
;
Clone Cells
;
DNA
;
DNA, Complementary
;
Electrophoresis, Polyacrylamide Gel
;
Genome
;
Inclusion Bodies
;
Infectious pancreatic necrosis virus*
;
Molecular Weight
;
Nucleopolyhedrovirus*
;
Recombination, Genetic*
;
RNA
6.Change of the Lymphocyte Stimulation Index and the Serum Immunoglobulin in Experimental Obstructive Jaundiced Rats.
Chang Hyeok AHN ; Dong Goo KIM
Journal of the Korean Surgical Society 2000;58(1):9-16
BACKGROUND: The high incidence of operative complications in patients with jaundice is associated with an impaired immune system, an increased systemic and portal endotoxemia due to the decreased hepatic reticuloendothelial function, and increased immune inhibitory factors such as bilirubin and bile acids. This study was designed to evaluate the immune response and the histological changes in rats with obstructive jaundice induced by common bile-duct (CBD) ligation. METHODS: Thirty-two male Wister rats weighing 250-320 gm were enrolled in this study and divided into 2 groups: a control group and a CBD ligation group. Under general anesthesia, the CBD was ligated with silk and resected for the CBD ligation group, but it was only isolated for the control group. The rats were sacrificed at the lst, the 2nd, and the 3rd weeks after ligation, and we evaluated the chemistries of the liver function, the lymphocytes stimulation index, the serum immunoglobulin levels, and the histological changes in the bile-duct-ligated livers. RESULTS: 1. There was no statistical difference in the serum creatinine levels between the control and the CBD ligation groups. At the lst week in the CBD ligation group, the serum AST, ALT, and bilirubin levels were statistically higher than those of the control group (p<0.05), which were slightly increased thereafter. 2. The lymphocyte stimulation index (LSI) of peripheral lymphocytes in the CBD ligation group was significantly decreased with the passing of time, but that of the control group was not. The LSI of splenocytes was statistically higher than that of peripheral lymphocytes in the control group, and the LSI of splenocytes was significantly decreased at the lst and the 2nd weeks, but was only slightly decreased, without statistical significance, at the 3rd week, in the CBD ligation group. 3. The serum immunoglobulin G (Ig G) level was significantly decreased at the lst week in the CBD ligation group compared with that of the control group and was slightly decreased, without statistical significance, at the 2nd and the 3rd weeks in the CBD ligation group. The serum immunoglobulin A (Ig A) level was extremely low in all groups, but this result had no statistical significance. 4. After CBD ligation, livertissues showed progressive bile ductular proliferation in the portal tract and an infarct with inflammatory infiltration into the central vein area and cholestatic change. CONCLUSION: These results suggest that derangement of the liver functions, suppresed lymphocytes function, and decreased immunoglobulin production might be associated with impairment of the immune response in bile-duct-ligated rats.
Anesthesia, General
;
Animals
;
Bile
;
Bile Acids and Salts
;
Bilirubin
;
Creatinine
;
Endotoxemia
;
Humans
;
Immune System
;
Immunoglobulin A
;
Immunoglobulin G
;
Immunoglobulins*
;
Incidence
;
Jaundice
;
Jaundice, Obstructive
;
Ligation
;
Liver
;
Lymphocyte Activation*
;
Lymphocytes*
;
Male
;
Rats*
;
Silk
;
Veins
7.Malignant Fibrous Histiocytoma: Treated with Free Vascularized Fibular Graft after Radical Resection
Jin Hwan AHN ; Myung Chul YOO ; Shin Hyeok KANG ; Kyung Yul CHOI ; Hoi Chang KIM
The Journal of the Korean Orthopaedic Association 1981;16(3):689-692
Malignant fibrous histiocytoma of the bone is relatively rare than that affecting the soft tissue. The authors have first experienced a case of malignant fibrous histiocytoma affecting the distal tibia of thirty-two years old woman in Korea. We obtained good results from free vascularized fibular graft after radical resection in stead of amputation. A case of malignant fibrous histiocytoma of the bone is reported with brief review of literature.
Amputation
;
Female
;
Histiocytoma, Malignant Fibrous
;
Humans
;
Korea
;
Tibia
;
Transplants
8.Replantation of Hand Amputated Through the Palmar Arch Level
Myung Chul YOO ; Shin Hyeok KANG ; Hoi Chang KIM ; Young Girl LEE
The Journal of the Korean Orthopaedic Association 1982;17(5):845-853
The value of replantation of parts of the upper limb is well established and replantation of a digit has now be come a standard procedure. However, there are few reports of replantation of hand amputated through the palmar arch level. We have reviewed 14 cases of 14 patients replantation of hand amputated through the arterial palmar arch level from Mar. 1976 through Mar. 1982. The success rate in our series is 64 percent. This is slightly lower than the other levels due to its anatomical complexity. According to the anatomical complexity and distribution of nerves and vessels, it is divided to three levels. In level A, the superficial palmar arch and/or the deep palmar arch should be repaired. In level B, the princeps pollicis artery should be repaired after anastomosis of the superficial and deep palmar arch. In level C, each common palmar digital artery should be repaired but if it is impossible to repair of all fingers, replantation of thumb and index should be performed as possible. Meticulous microsurgical technique and precise anatomical knowledge is mandatory for replantation of the palmar arch level.
Arteries
;
Extremities
;
Fingers
;
Hand
;
Humans
;
Replantation
;
Thumb
;
Upper Extremity
9.Three Cases of Orbitofrontal Cholesterol Granuloma.
Ju Hee CHANG ; Sang Hyeok LEE ; Wha Sun CHUNG
Journal of the Korean Ophthalmological Society 2005;46(7):1228-1234
PURPOSE: To report three cases of orbitofrontal cholesterol granuloma. METHODS: The study subjects were three patients with chief complaints of proptosis and upgaze limitation of ocular movement. Exophthalmometric values were 4~8 mm by Hertel exophthalmometer. Orbital CT and MRI scans were taken in all patients, and regarded as orbitofrontal cholesterol granuloma. In all cases, excisional biopsy was done through the lateral approach. RESULTS: Orbital CT scan showed an isodense to hypodense, well-defined, homogeneous mass and osteolytic lesion in the adjacent superolateral bony orbit. Orbital MRI scan showed a mass with high signal intensity in both T1- and T2-weighted images. Histopathologically, the specimen showed numerous slits like cholesterol clefts surrounded by multinucleated, foreign body type, giant cells with hemosiderin pigments. CONCLUSIONS: Orbitofrontal cholesterol granuloma, although rare, has typical clinical and radiologic features. Surgical excision has a high success rate without recurrence.
Biopsy
10.Heat Production and Thermal Necrosis by Cortical Drilling.
Kuhn Sung WHANG ; Hyun Kee CHUNG ; Choong Hyeok CHOI ; Jong Heon KIM ; Chang Woo HAN ; Doo Jin PAIK
Journal of Korean Orthopaedic Research Society 1999;2(2):164-170
PURPOSE: The present study was performed to determine the optimum conditions(RPM, load, sharpness of drill) for drilling human cortical bone with standard drill, and to evaluate the histological changes occuring in bone after drilling. MATERIALS AND METHODS: in experiment I, we measured temperature elevations and the durations of temperature elevation in cadaveric femoral cortices at specific distances from the drill hole wall while drilling. The effects of drilling force, speed and new versus worn drill on the termperature were determined. In experiment II, we also measured temperature elevations in the same manner in porcine femoral cortices and evaluated the histological changes occuring in bone after drilling. RESULTS: In experiment I, the most significant temperature elevation(68.4degrees C ) was found when worn drill was used. The lower drilling force and faster speed resulted in 55.1degrees C and 45.8degrees C temperature elevation, respectively. However, drill diameter was not a significant factor for temperature elevation. In experiment II, greater heat production was measured with worn drill, at lower drilling forces, at faster drill speed. The acute histologic reactions in bone were hyperemia, degeneration of osteocytes, change in bone stainability, tears, and fragmentation of the bone edges around the drill holes. The observed histological changes were proportional to the amount of trauma produced, that is, the greater the degree of thermal irritation, the greater the degree of histologic activity. CONCLUSION: In cortical drilling, greater heat production was measured with worn drill, at lower drilling forces, at faster drill speed and the greater the degree of thermal irritation, the greater the degree of histologic activity. A further study of the reaction of bone to drilling at longer intervals of time at different conditions may possibly show whether aseptic thermal necrosis could be prevented.
Cadaver
;
Hot Temperature*
;
Humans
;
Hyperemia
;
Necrosis*
;
Osteocytes
;
Thermogenesis*