The aim of this study was to compare wear resistance of resin denture teeth opposing various restorative materials. The wear resistance of conventional acrylic resin teeth (Trubyte Biotone) and three high-strength resin teeth(Bioform IPN, Endura, SR-Orthosit-PE) opposing different restorative materials (gold alloys, dental porcelain, composite resin) was compared. Wear tests were conducted with a sliding-induced wear testing apparatus which applied 100,000 strokes to the specimen in an mesio-distal direction under conditions of 100 stroke/min and constant loading of 1Kgf/tooth. Wear resistance of the resin denture teeth was evaluated by the following criteria : 1) wear depth, 2)weight loss, and 3) SEM observation. Results were as follows. 1. When opposed to gold alloys and composite resin, high-strength resin teeth showed superior wear resistance compared to acrylic resin teeth. But, in cases opposing dental porcelain, differences between the wear of the high-strength and acrylic resin teeth were not statistically significant (p<0.05). 2. When comparing wear resistance among high-strength resin teeth, opposing gold alloys, Endura was slightly more resistant and while in cases opposing dental porcelain, SR-Orthosit-PE was showed to be slightly resistant(p<0.05). 3. The wear of high-strength resin teeth was greater by 5 to 7 times when opposing porcelain and 2 to 3 times when opposing composite resin compared to gold alloys(p<0.05). 4. SEM observations of the wear surface showed that wear of resin teeth opposing gold alloys is a fatigue type of wear and wear of resin teeth opposing dental porcelain is fatigue and abrasion type of wear. Trubyte Biotone showed more severe fatigue type of wear than high-strength resin teeth. In conclusion, the use of dental porcelain should seriously be considered as restorative material in cases opposing resin denture teeth and improvement seems to be needed on resin teeth in the areas of wear resistance.
Dental Alloys ; Dental Porcelain ; Dentures* ; Fatigue ; Gold Alloys ; Stroke ; Tooth*

OBJECTIVES: This research was intended to investigate the relationship between manganese and malodndialdehyde concentration in tissues of rats exposed to maganese chloride. METHODS: The study groups were 12 manganese treated rats and 9 control rats. Manganese treated rats were given intraperitoneally manganese chloride (Mn, 4 mg/kg) daily for a period of 30 days except Sunday. Control rats were injected 1ml of saline. The plasma manganese concentrations of rats were determined by graphite furnace atomic absorption spectrometry. The tissue manganese concentration was determined by flame atomic absorption spectrometry. Malondialdehyde, the product of lipid peroxidation was determined by ultraviolet-visible spectrophotometry. The plasma malondialdehyde was determined by gas chromatography with mass-detector. Protein concentration was quantified by ultraviolet-visible spectrometry and was used for the compensation of tissue malondialdehyde and manganese concentration. RESULTS: Manganese concentrations of plasma, brain, liver, and pancreas were very significantly higher in the manganese-treated rats than in the control rats. Malondialdehyde concentration of plasma, brain, and pacrease were significantly higher in the manganese-treated rats than in the control rats. The concentration of malondialdehyde was correlated with manganese levels in plasma, brain and pancreas. Conclusion: Based on the results obtained as above, it was concluded that the malondialdehyde, product of lipid peroxidation was related to the cell death due to dosing excess manganese.
Absorption ; Animals ; Brain ; Cell Death ; Chromatography, Gas ; Compensation and Redress ; Graphite ; Lipid Peroxidation ; Liver ; Malondialdehyde* ; Manganese* ; Pancreas ; Plasma ; Rats* ; Spectrophotometry ; Spectrum Analysis

The instability of the degenerative spondylolisthetic lumbar spine was clinically evaluated by patients symptoms and serial radiograms. With X-ray films of patients lumbar spine, the lumbosacral angle, the sacral angle, the vertebral height difference between anterior and posterior surface of the 5th lumbar vertebra and the level of intercristal line were analysed. And the results of treatment were analysed too. The Results were as follows: 1) In degenerative spondylolisthetic L3 and L4 spines, facets were arranged in sagittal plane and sacrum was vertically arranged, but in L5 facets were coronally arranged and sacrum and in horizontal plane. 2) The lumbosacral angle was 149.9 and the average difference between anterior and posterior height of L5 vertebral body was 3mm. These results revealed that sacrum was more vertical and the 5th vertebral body was more rectangular, so lumbar lordosis was decreased as a whole. 3) The intercristal line was passed at IA or L4–5 interspace in 72.1% of cases(normal:95.8%), so L4 vertebra was placed in higher level. 4) In group A posterolateral fusion was done in 2 cases. Among group B and C, operation was done in 9 cases;4 cases with laminectomy and 5 cases with laminectomy and posterolateral fusion. Two years after surgery, slipping and instability were far advanced in 2 laminectomized cases for whom posterolateral fusion was followed later. 5) Unstable group of degenerative spondylolisthesis with severe neurological symptoms and claudication must be treated by decompressive laminectomy and posterolateral fusion, especially in patients under 60 years of age. 6) Young woman having flattened lumbar curve without slipping, narrowed disc space of L4–5, high-seated L4 and vertical sacrum is thought to be in prespondylolisthetic stage of degenerative origin; therefore, intensive back muscle exercise to prevent the slipping should be performed and periodic X-ray examinations should be followed up to detect the progress of the disease.
Animals ; Back Muscles ; Female ; Humans ; Laminectomy ; Lordosis ; Sacrum ; Spine ; Spondylolisthesis ; X-Ray Film

No abstract available.
Encephalitis, Herpes Simplex* ; Herpes Simplex*

No abstract available.
Encephalitis, Herpes Simplex* ; Herpes Simplex*

Clinical observation was made on 131 cases of the unstable spine injury treated at the Orthopedic Surgery Department of Busan National University Hospital during the period from January 1974 to December 1981. The results obtained were as follows: 1. More than two-thirds of patients were between the age of 20 and 40, and the proportion of males to females showed a ratio of 5.9 to 1. The most common cause of injury was falling at an industrial area, rating 64.1% of all cases. 2. Fracture level was observed 31.3% in the first lumbar level, 24.4% in the twelfth thoracic vertebra, and 67.9% between the twelfth thoracic vertebra and the second lumbar vertebra. 3. Mechanisms of injury were 44.3% by pure flexion, 26.7% by flexion and rotation, 15.3% by direct shearing force, and 13.7% by vertical compression. 4. The fracture with lower extremity paralysis was due to the rotational fracture dislocation, which comprised 66% of all. 5. Kyphosis increased to the average of 10.6 degree in the case of decompressive laminectomy and of 3.4 degree in the case of spinal fusion. 6. The anatomical alignment and a definite stability could be obtained by the use of Harringtons rod in the cases of the unstable thoracolumbar fracture and fracture-dislocation. In 3 cases of all, we could get satisfactory results 1 month after the day injury occured. 7. In case of complete paralysis of lower extremity, it was found only 9.4% showed partial recovery, neurologically, and 61.9% of the patients with incomplete paralysis were also partly recovered. 8. The most common complication was urinary tract infection, which comprised 83% of the cases. With the use of intermittent urinary catheterization, the voiding reflex recovered within 4 months in most cases.
Accidental Falls ; Busan ; Dislocations ; Female ; Humans ; Kyphosis ; Laminectomy ; Lower Extremity ; Male ; Orthopedics ; Paralysis ; Reflex ; Spinal Fusion ; Spine ; Urinary Catheterization ; Urinary Catheters ; Urinary Tract Infections

No abstract available in English.
Child ; Hip ; Humans

Titanium alloy has been widely used as material for total knee arthroplasty(TKA). However, titanium alloy has frequently been reported as causing black staining of the periprosthetic tissues as a result of debries from metallic wear and tissue reaction. We report six cases of failed TKA in five patients, in which the tibial tray and/or metal backed patellar components were composed of titanium alloy. Wear, breakage or separation of the ultra-high molecular weight polyethylene of tibial insert and/or patellar component, which allowed metal-on-metal friction and aggravated the production of metal wear debries, were observed in all cases. The average time from primary operation to revision was 5 year and 3 months (range, 9 months to 8 year and 8 months). In all cases, patients showed painful swelling of knee jont and radiopaque periarticular deposits on radiogrphs. Most of radiographs showed abnormal position of the metallic components and metal line sign. Histology of synovium showed abundant titanium particles lying free and within histiocytes, and polyethylene and cement particles with foreign-body type giant cell reaction. The synovial lining showed a preliferative reaction and abundant fibrosis was noted. On polarizing briefringent. Elemental analysis of metal particles on histologic section, using energy dispersive X-ray spectrophotometer (EDS ; EDAX PV9900) unit attached to a transmission electron microscope, detected the titanium peak. Radiopaque metallic densitien in the painful knee after TKA are highly suggestive findings of titanium reaction. Tissue reaction in response to the metal wear debries from titanium prosthesis may have contributed to the early failure of these implants.
Alloys ; Arthroplasty, Replacement, Knee ; Deception ; Fibrosis ; Friction ; Giant Cells ; Histiocytes ; Humans ; Knee ; Molecular Weight ; Polyethylene ; Prostheses and Implants ; Synovial Membrane ; Titanium

No abstract available.
Psychosurgery*

Hypertensive encephalopathy is an acute clinical syndrome that shows central nerve dysfunction with sudden and marked elevation in blood pressure. But its pathophysiologic mechanisms, clinical courses and prognosis are still not clear. In order to study clinical manifestations and response to treatment in patients with hypertensive encephalopathy, we reviewed 45 patients with hypertensive encephalopathy who were admitted in Dept. of Internal Medicine, National Medical Center, from January 1975 to December 1984. The following results were obtained: 1) The ratio of male to female was 1.1:1. The peak age of incidence was in the 6th and 7th decade with mean age of 57.5 years. 2) Among 45 patients, only 29 had known history of hypertension and the average duration of hypertension was 8.1+/-3.6 years. 3) The most common sympotm was severe headache (68.9%). And altered consciousness, nausea and/or vomiting, focal neurologic signs and visual disturbance were also common symptoms in decreasing order of frequency. 4) Funduscopic examination showed hypertensive retinopathy in 20 of 24 (91.7%) patients and lumbar puncture revealed increased CSF pressure in 12 of 20 (60%) patients. 5) In most patients, the mean interval to symptomatic improvement was 2.1 days after administration of anti hypertensive agents, but in 6 patients with initial mean arterial blood pressure above 170mmHg, 4 patients showed delayed response and 2 patients were expired.
Antihypertensive Agents ; Arterial Pressure ; Blood Pressure ; Consciousness ; Female ; Headache ; Humans ; Hypertension ; Hypertensive Encephalopathy* ; Hypertensive Retinopathy ; Incidence ; Internal Medicine ; Male ; Nausea ; Neurologic Manifestations ; Prognosis ; Spinal Puncture ; Vomiting