1.Comparison of the degree of conversion of light-cured resin cement in regard to porcelain laminate thickness, light source and curing time using FT-IR.
Chi Sung YUH ; Jee Hwan KIM ; Sun Jai KIM ; Yong Keun LEE ; June Sung SHIM
The Journal of Korean Academy of Prosthodontics 2009;47(4):416-423
STATEMENT OF PROBLEM: The degree of light attenuation at the time of cementation of the PLV restoration depends on characteristics such as thickness, opacity and shade of the restorations, which interfere with light transmittance and, as a result, may decrease the total energy reaching the luting cement. PURPOSE: The purpose of this study was to compare the degree of conversion of light-cured resin cements measuring by FT-IR in regard to different thickness, light devices and curing time. MATERIAL AND METHODS: In the control group, a clear slide glass (1.0 mm) was positioned between the light cured resin cement and light source. The specimens of ceramics were made with IPS Empress Esthetic. The ceramics were fabricated with varying thicknesses-0.5, 1.0, 1.5 mm with shade ETC1. Rely X(TM) Veneer with shade A3, light-cured resin cement, was used. Light-activation was conducted through the ceramic using a quartz tungsten halogen curing unit, a light emitting diode curing unit and a plasma arc curing unit. The degree of conversion of the light-cured resin cement was evaluated using FT-IR and OMNIC. One-way ANOVA and Tukey HSD test were used for statistical analysis (alpha< .05). RESULTS: The degree of conversion (DC) of photopolymerization using QTH and LED was higher than results of using PAC in the control group. After polymerization using QTH and LED, the DC results from the different ceramic thickness- 0.5 mm, 1.0 mm, 1.5 mm- did not show a significant difference when compared with those of control group. However, the DC for polymerization using PAC in the 1.5mm ceramic group showed significantly lower DC than those of the control group and 0.5 mm ceramic group (P<.05). At 80 s and 160 s, the DC of light-cured resin cement beneath 1.0 mm ceramic using LED was significantly higher than at 20 s (P<.05). CONCLUSION: Within the limitation of this study, when adhering PLV to porcelain with a thickness between 0.5 - 1.5 mm, the use of PAC curing units were not considered however, light cured resin cements were effective when cured for over 40 seconds with QTH or LED curing units. Also, when curing the light cured resin cements with LED, the degree of polymerization was not proportional with the curing time. Curing exceeding a certain curing time, did not significantly affect the degree of polymerization.
Cementation
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Ceramics
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Dental Porcelain
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Enzyme Multiplied Immunoassay Technique
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Glass
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Light
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Plasma
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Polymerization
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Polymers
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Quartz
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Resin Cements
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Tungsten
2.Surgical Outcome of Adult Idiopathic Chiari Malformation Type 1.
Woon Tak YUH ; Chi Heon KIM ; Chun Kee CHUNG ; Hyun Jib KIM ; Tae Ahn JAHNG ; Sung Bae PARK
Journal of Korean Neurosurgical Society 2016;59(5):512-517
OBJECTIVE: The pathophysiology of idiopathic Chiari malformation (CM) type 1 is disturbance of free cerebrospinal fluid (CSF) flow and restoration of normal CSF flow is the mainstay of treatment. Additional migration of the medulla oblongata in pediatric patients is referred to as CM type 1.5, but its significance in adult patients is unknown. This study is to compare surgical outcomes of adult idiopathic CM type 1.5 with that of type 1. METHODS: Thirty-eight consecutive adult patients (M : F=11 : 27; median, 33.5; range, 18–63) with syringomyelia due to idiopathic CM type 1 were reviewed. Migration of the medulla oblongata was noted in 13 patients. The modified McCormick scale (MMS) was used to evaluate functional status before and one year after surgery. All patients underwent foramen magnum decompression and duroplasty. Factors related to radiological success (≥50% decrease in the diameter of the syrinx) were investigated. The follow-up period was 72.7±55.6 months. RESULTS: Preoperative functional status were MMS I in 11 patients and MMS II in 14 of CM type 1 and MMS I in 8 and II in 5 of CM type 1.5. Of patients with MMS II, 5/14 patients in group A and 3/5 patients in group B showed improvement and there was no case of deterioration. Radiological success was achieved in 32 (84%) patients and restoration of the cisterna magna (p=0.01; OR, 46.5) was the only significant factor. CONCLUSION: Migration of the medulla oblongata did not make a difference in the surgical outcome when the cisterna magna was restored.
Adult*
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Arachnoid
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Cerebrospinal Fluid
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Cisterna Magna
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Decompression
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Follow-Up Studies
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Foramen Magnum
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Humans
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Medulla Oblongata
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Rhombencephalon
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Syringomyelia
3.Korean Patients with Superwarfarin Intoxication and Their Outcome.
Junshik HONG ; Ho Young YHIM ; Soo Mee BANG ; Sung Hwa BAE ; Young Jin YUH ; Sung Soo YOON ; Hwi Joong YOON ; Seung Taik KIM ; Hyun Sook CHI
Journal of Korean Medical Science 2010;25(12):1754-1758
This observational study aimed at evaluating recent superwarfarin intoxication of Korean patients. Ten patients were diagnosed as or highly suspicious for superwarfarin intoxication. Case report forms described by attending hematologists of the patients were collected and analyzed. Bleeding symptoms were varied among the patients. Patients uniformly showed prolonged prothrombin time (PT) and activated thromboplastin time (aPTT) with decreased activity of vitamin K dependent coagulation factors. Positive serum brodifacoum test results in 4 of 5 requested patients contributed to confirmatory diagnosis. Psychiatric interview revealed an attempted ingestion in one patient. High dose vitamin K1 therapy promptly corrected prolonged PT and aPTT, but hasty discontinuation caused repeated bleeding diathesis in 6 patients. Route of intoxication was unknown or not definite among 8 of 10 patients. Three patients had a possibility of environmental exposure considering their occupations: there might be intoxication by transdermal absorption or inhalation. Therefore, high dose and prolonged use of vitamin K1 therapy is necessary for effective detoxification. Further detailed investigation on environmental exposure and efforts to improve availability of the blood level test in clinic are requested.
4-Hydroxycoumarins/*poisoning
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Adult
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Aged
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Aged, 80 and over
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Anticoagulants/*poisoning
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Antifibrinolytic Agents/therapeutic use
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Environmental Exposure
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Female
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Hemorrhage/*chemically induced/diagnosis/drug therapy
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Humans
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Male
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Middle Aged
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Partial Thromboplastin Time
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Prothrombin Time
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Republic of Korea
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Treatment Outcome
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Vitamin K 1/therapeutic use