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.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
3.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
4.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
5.Motor Recovery Effect of Minocycline in Spinal Cord Injured Rats.
Hyun Yoon KO ; Jae Hyeok CHANG ; Jae Heung PARK
Journal of the Korean Academy of Rehabilitation Medicine 2006;30(6):565-570
OBJECTIVE: To observe motor recovery after spinal cord injury (SCI) by time and impact strength in minocycline administration rat. METHOD: Forty Sprague-Dawley rats were divided into four groups according to minocycline administration and damage heights. Rats in first group were damaged in 2.5 cm heights, and injected with minocycline. In second group, minocycline was not injected. Rats in third group were damaged in 5 cm heights, and injected with minocycline. In fourth group, rats were damaged in 5 cm and minocycline was not injected. Rats received injury by the force-calibrated weight drop device and first and third groups injected minocycline 90 mg/kg immediately after injury and injected 45 mg/kg every 12 hours. Motor recovery was determined by the Basso-Beattie-Bresnahan (BBB) locomotor rating scale at 1st, 7th, 14th, 21st, and 28th day after injury. RESULTS: The BBB scores were significantly higher in first and third groups as compared to second and fourth groups after injury. There was significant change of BBB scores in first group as compared to third. CONCLUSION: After injury, BBB scores were significantly higher in minocycline treated rats as compared to the control. Minocycline might have beneficial effects on the recovery cascade after SCI.
Animals
;
Minocycline*
;
Rats*
;
Rats, Sprague-Dawley
;
Spinal Cord Injuries
;
Spinal Cord*
6.Secondary Parkinsonism due to Extrapontine Myelinolysis without Central Pontine Myelinolysis: A case report.
Jae Heung PARK ; Jae Hyeok CHANG ; Ji Sang PARK ; Si Chul CHO
Journal of the Korean Academy of Rehabilitation Medicine 2007;31(1):119-112
Parkinsonism is characterized by clinical symptoms of rigidity, bradykinesia, tremor, and gait disturbance. There are many causes of secondary parkinsonism. The present report discusses a secondary parkinsonism of extrapontine myelinolysis (EPM) without central pontine myelinolysis (CPM) after rapid correction of hyponatremia. EPM is a demyelinating process of the brain. EPM with CPM is relatively common, but EMP without CPM is rare. A 57- year-old woman with Tsutsugamushi disease had a subacuteonset of parkinsonism on the fourteenth day after a rapid correction of severe hyponatremia. Magnetic resonance imaging of the bilateral basal ganglia showed a high signal intensity on T2-weighted images, and a low signal on T1- weighted images. She was started on levodopa, and parkinsonian features slowly improved. We report an unusual case of EPM without CPM, that presented with parkinsonism.
Basal Ganglia
;
Brain
;
Female
;
Gait
;
Humans
;
Hypokinesia
;
Hyponatremia
;
Levodopa
;
Magnetic Resonance Imaging
;
Myelinolysis, Central Pontine*
;
Parkinson Disease, Secondary*
;
Parkinsonian Disorders
;
Scrub Typhus
;
Tremor
7.Comparative Analysis of Unstable Burst Fracture According to the Methodology of Surgical Treatment.
Ye Soo PARK ; Yee Suk KIM ; Chang Nam KANG ; Choong Hyeok CHOI ; Jae Lim CHO
Journal of Korean Society of Spine Surgery 2004;11(4):278-284
STUDY DESIGN: A retrospective analysis of the results of various methodologies for the surgical treatment of an unstable burst fracture with posterior column injuries. OBJECTIVES: To compare the radiological and clinical results in unstable burst fractures, treated with various surgical methodologies (anterior, posterior and combined fusion), and to confirm their efficacy. LITERATURE REVIEW SUMMARY: Many authors recommended various surgical methods for the treatment of an unstable burst fracture, and of these, combined fusion is recommended for the preservation of stability. MATERIALS AND METHODS: A retrospective review of results was carried out on 22 patients, confirmed with an unstable burst fracture associated with a posterior column injury, between Nov. 1996 and Mar. 2003. The preoperative plane x-ray, CT and MRI, and the last postoperative follow up plane X-ray and CT, in 22 unstable burst fracture patients, were reviewed. The authors looked for laminar fracture, facet injury and inter-spinous widening in the plane x-ray, canal compromise on the CT, and a posterior ligament injury and dural tear on the MRI. The neurological injury was evaluated using the Bardford and McBride criteria and the clinical result with the Denis' pain and work scale. RESULTS: In the anterior fusion group, the radiological findings showed 3 laminar fractures, 2 facet injuries, 7 inter-spinous widening and 8 posterior ligament injuries. In the posterior fusion group, they showed 5 laminar fractures, 4 facet injuries, 5 inter-spinous widening and 5 posterior ligament injuries. In the combined fusion group, they showed 5 laminar fractures, 4 facet injuries, 4 inter-spinous widening and 5 posterior ligament injuries. The average canal compromise was 54.3% in cases of anterior fusion, 20.9% of posterior fusion and 74% of the combined fusion groups. A dural tear was found in 1 each of the anterior and posterior and 4 of the combined group. From the clinical results, improvements of the neurology in the anterior, posterior and combined groups were 2.0, 1.7 and 1.3 degrees, respectively. From the Denis' pain & work scale better than good degrees were shown in 3 of the anterior, 4 of the posterior and 2 of the combined groups. CONCLUSIONS: In conclusion, there were no differences in the improvements of the neurology and clinical results according to the surgical methodology employed. However, the use of combined fusion is recommended for the preservation of stability in an unstable burst fracture with combined posterior ligament and bony injuries as well as with severe canal compromise.
Follow-Up Studies
;
Humans
;
Ligaments
;
Magnetic Resonance Imaging
;
Neurology
;
Retrospective Studies
;
Tears
8.Comparative Analysis of Unstable Burst Fracture According to the Methodology of Surgical Treatment.
Ye Soo PARK ; Yee Suk KIM ; Chang Nam KANG ; Choong Hyeok CHOI ; Jae Lim CHO
Journal of Korean Society of Spine Surgery 2004;11(4):278-284
STUDY DESIGN: A retrospective analysis of the results of various methodologies for the surgical treatment of an unstable burst fracture with posterior column injuries. OBJECTIVES: To compare the radiological and clinical results in unstable burst fractures, treated with various surgical methodologies (anterior, posterior and combined fusion), and to confirm their efficacy. LITERATURE REVIEW SUMMARY: Many authors recommended various surgical methods for the treatment of an unstable burst fracture, and of these, combined fusion is recommended for the preservation of stability. MATERIALS AND METHODS: A retrospective review of results was carried out on 22 patients, confirmed with an unstable burst fracture associated with a posterior column injury, between Nov. 1996 and Mar. 2003. The preoperative plane x-ray, CT and MRI, and the last postoperative follow up plane X-ray and CT, in 22 unstable burst fracture patients, were reviewed. The authors looked for laminar fracture, facet injury and inter-spinous widening in the plane x-ray, canal compromise on the CT, and a posterior ligament injury and dural tear on the MRI. The neurological injury was evaluated using the Bardford and McBride criteria and the clinical result with the Denis' pain and work scale. RESULTS: In the anterior fusion group, the radiological findings showed 3 laminar fractures, 2 facet injuries, 7 inter-spinous widening and 8 posterior ligament injuries. In the posterior fusion group, they showed 5 laminar fractures, 4 facet injuries, 5 inter-spinous widening and 5 posterior ligament injuries. In the combined fusion group, they showed 5 laminar fractures, 4 facet injuries, 4 inter-spinous widening and 5 posterior ligament injuries. The average canal compromise was 54.3% in cases of anterior fusion, 20.9% of posterior fusion and 74% of the combined fusion groups. A dural tear was found in 1 each of the anterior and posterior and 4 of the combined group. From the clinical results, improvements of the neurology in the anterior, posterior and combined groups were 2.0, 1.7 and 1.3 degrees, respectively. From the Denis' pain & work scale better than good degrees were shown in 3 of the anterior, 4 of the posterior and 2 of the combined groups. CONCLUSIONS: In conclusion, there were no differences in the improvements of the neurology and clinical results according to the surgical methodology employed. However, the use of combined fusion is recommended for the preservation of stability in an unstable burst fracture with combined posterior ligament and bony injuries as well as with severe canal compromise.
Follow-Up Studies
;
Humans
;
Ligaments
;
Magnetic Resonance Imaging
;
Neurology
;
Retrospective Studies
;
Tears
9.Venous Hemangioma Presenting as a Mediastinal Cyst on CT.
Soo Jin CHOI ; Gou Young KIM ; Chul Hi PARK ; Jae Ik LEE ; Chang Hyeok AN
Journal of the Korean Radiological Society 2007;56(5):483-486
Mediastinal hemangiomas are extremely rare tumors that originate from vascular endothelial cells. It is well known that mediastinal hemangiomas appear on CT as solid masses with heterogeneous enhancement. We describe here a case of venous hemangioma, and the tumor was seen of the CT scan as a well-marginated cystic mass with a fluid-fluid level in the middle mediastinum; this mass mimicked a foregut cyst or cystic lymphangioma.
Endothelial Cells
;
Hemangioma*
;
Lymphangioma, Cystic
;
Mediastinal Cyst*
;
Mediastinum
;
Tomography, X-Ray Computed
10.Comparative accuracy of new implant impression technique using abutments as impression copings with an angulated implant model.
Hyeok Jae LEE ; Chang Whe KIM ; Young Jun LIM ; Myung Joo KIM
The Journal of Korean Academy of Prosthodontics 2008;46(2):201-208
STATEMENT OF PROBLEM: A new implant impression technique which use abutments as impression coping, and use resin cement as a splinting material was described. Accuracy of this technique was compared with conventional closed tray and resin splinted open tray technique for a 15degrees angled 3-implant model MATERIAL AND METHODS: A dental stone master model with 3 linearly positioned implant analogue and a reference framework which was passively fitted to it were fabricated. The center analogue was perpendicular to the plane of model and the outer analogues had a 15degrees angulation forward or backward. 10 closed tray impressions, 10 resin splinted open tray impressions, 10 abutment-resin framework cementation impressions and 10 abutment-metal framework cementation impressions were made with additional silicone material and poured with dental stone. A light microscope with image processing was used to record the vertical gap dimension between reference framework and analogue of duplicated cast made with each 4 impression techniques. Statistical analysis used one-way ANOVA with post-hoc tests Tukey test of .05 level of significance RESULTS: Significant difference in the vertical gap dimension was found between closed tray technique; 74.3 (+/-33.4)micrometer and resin splinted open tray technique, and two other new technique. (P>.05) Abutment-metal framework cementation technique;42.5 (+/-11.9)micrometer was significantly different from resin splinted open tray technique. (P<.05) Abutmentresin framework cementation technique;51.0 (+/-14.1)micrometer did not differ significantly from resin splinted open tray technique;50.3 (+/-16.9)micrometer. (P>.05) CONCLUSION: Within limitations of this study, the accuracy of implant level impressions of resin splinted open tray technique was superior to that of closed tray technique. A new technique using abutment and metal framework cementation was more accurate than resin splinted open tray technique.
Cementation
;
Light
;
Resin Cements
;
Silicones
;
Splints