Recently, various implant cylinders were supplied, especially received gold cylinders, cast cylinders produced from premade gold and plastic cylinders and plastic cylinders. This study measured and compared precise fit produced when using conventional gold and plastic cylinders. The comparative fit of lapped and non-lapped castings made from plastic pattern was examined. The implant/abutment interface fit was evaluated by scanning electron microscopy(SEM) for each of four cylinders. The following results were obtained: 1. The case of plastic cylinder showed 9.67+/-1.50micrometer gap Steri-Oss fixture was connected. 2. The case oflapped casting made from plastic cylinder showed 3.01+/-2.81micrometer gap when Steri-Oss fixture was connected. 3. The case of gold/plastic cylinder showed 9.80+/-1.68micrometer gap when Steri-Oss fixture was connected. 4. The case of gold cylinder showed 5.47+/-2.43micrometer gap when Steri-Oss fixture was connected. 5. In case of each cylinder which was connected with Steri-Oss fixture, the size of gap was showed less in the order of the case of gold/plastic cylinder, the case of plastic cylinder, the case of gold cylinder and the case of lapped casting made from plastic cylinder. As results of this study, the use of premade gold cylinder offers an advantage over plastic patterns in precise fit. When plastic patterns are used, polishing of implant cylinder components should provide precise fit.
Plastics* ; Prostheses and Implants*

No abstract available.
Animals ; Carcinogenesis* ; Rats*

No abstract available.
Depression*

The purpose of this study was to compare the casting problem and corrosion behavior in two types of HL Hexed abutments of the Steri-Oss system : gold/plastic coping and gold coping. The anodic Polarization behavior, the galvanic corrosion between abutments and Type III gold alloys, before and after casting were analyzed, and the crevice corrosion of casting samples was analyzed with the CPPT test and the SEM. The results are as follows ; 1. Anodic polarization behavior of samples ; Before casting, gold/plastic coping and gold coping was shown to have a similar corrosion patterns. TypeIII casting gold alloy was shown to have a lower corrosion potential and passivation film. Corrosion potential of the case of gold/plastic coping after casting was higher than that of gold coping, but the region of passivation film for gold/plastic coping was smaller than that of gold coping. 2. Galvanic corrosion behavior of samples ; Contact current density between casting gold alloys and gold/plastic before casting was higher than that between gold coping and casting gold alloy. Galvanic corrosion of samples after casting was shown to have similar contact current density. 3. Crevice corrosion behavior of samples ; Crevice corrosion resistance of casting sample using gold coping was lower than that of casting sample using gold/plastic coping, and a severe corrosion pattern was observed at the abutment-casting gold alloy interface by the SEM.
Alloys* ; Corrosion* ; Gold Alloys

OBJECTIVE: The authors conducted this study to investigate the safety and efficacy of decompressive surgery alone in the treatment of lumbar spinal stenosis in the elderly population. METHODS: All charts and records of 323 patients aged 65 years or older who underwent lumbar spinal decompressive surgery without fusion for lumbar spinal stenosis in the period from September 2003 to August 2007 were reviewed. RESULTS: A total of 323 patients were identified. Mean age among patients were 72.6years. 197 patients(60.9%) underwent wide decompression, 95 patients(29.4%) had microscopic partial decompression, and 31 patients(9.5%) underwent bilateral decompression via unilateral approach. Perioperative morbidity seen was among 16 patients(4.9%). There were 5 patients(1.5%) reoperated for hematoma formation. Another 5 patients(1.5%) developed wound infection. Cerebrospinal fluid(CSF) leakage were noted among 3 patients(0.9%). 2 patients(0.6%) had urinary difficulty, and Steven Johnson syndrome developed in one patient(0.3 %). Clinical outcome was evaluated using Macnab's classification. 40 patients(12.4%) had excellent results, 241 patients(74.8%) had good results, 34 patients(10.3%) had fair results and 8 patients(2.5%) had poor outcome. CONCLUSION: Decompressive laminectomy alone is a relatively safe and effective treatment option for the elderly.
Aged ; Decompression ; Hematoma ; Humans ; Laminectomy ; Spinal Stenosis ; Wound Infection

Sulfuric acid can cause local or systemic effects after exposure by inhalation, ingestion, or topical application. Direct ingestion is the main exposure route for fatal sulfuric acid injury. Fatal accidents involving the inhalation of toxic sulfuric acid vapors are rare. Inhalation of sulfuric acid fumes causes severe irritation or corrosive damage to the upper respiratory tract. Consequently, severe congestion, edema, and inflammation of the mucous membranes of the upper respiratory passages hinder the entry of air into the lungs, possibly leading to fatalities in victims. A 35-year-old man died at his home after complaining of a severe sore throat. One day earlier, he had worked in a sulfuric acid tank in a copper-smelting plant while wearing an ordinary gas mask that offered no protection against sulfurous acid vapors. Upon autopsy, the larynx and epiglottis showed pronounced edema, congestion, and inflammation that histologically mimicked an acute bacterial suppurative inflammation, accompanied by severe pulmonary edema. A field analysis of the air inside the sulfuric acid tank revealed SO4(2-) positivity and a 40% sulfuric acid concentration.
Adult ; Autopsy ; Eating ; Edema ; Epiglottis ; Estrogens, Conjugated (USP) ; Humans ; Inflammation ; Inhalation* ; Larynx ; Lung ; Mucous Membrane ; Pharyngitis ; Plants ; Pulmonary Edema ; Respiratory Protective Devices ; Respiratory System ; Sulfur* ; Sulfuric Acids

No abstract available.
Deoxyglucose* ; Shock*

OBJECTIVE: The aim of this study is to explore the variation in perceptions about problem-based learning(PBL) according to the level of academic achievement and learning attitude in the nursing students of a junior college (3-year program). METHOD: Students (n=39) learned the respiratory and cardiac system with seven PBL packages and group-based learning for a semester in 2002. Students were asked to write reflective journals that focused on their learning perception after an experience with each learning package. A total of 208 journals were used for analysis. RESULT: Students positively perceived that PBL making them increase their sense of responsibility for learning and felt satisfaction with the learning process, and had a confidence in the use of clinical nursing interventions. On the other hand, they negatively perceived that PBL was a burden because it took more time than traditional learning tasks, and they experienced an anxiety about regular tests and felt conflicts and diffidences in the learning process. The negative perceptions were expressed more often from students with a low academic achievement and low learning attitude compared to others. CONCLUSION: Students perceived the PBL as effective in understanding the learning concepts in the clinical practice environment. PBL need to be supplemented by feedback-based lecture and facilitative strategies for academically low-achieved students.
Students, Nursing/*psychology ; *Problem-Based Learning ; Humans ; Female ; *Education, Nursing, Baccalaureate ; *Attitude ; Adult

No abstract available.
Brain* ; Emergencies* ; Emergency Service, Hospital* ; Humans

An antrochoanal polyp is a solitary polypoid mass that arises from the maxillary sinus, and protrudes through the natural ostium into the middle meatus, and reaches the choana, The polyp does not differ histologically from an ordinary nasal polyp, which is composed of edematous, hyperplastic submucosal connective tissue stroma, and is relatively hypocellular, In this sequence of events. Its computed tomographic(CT)findings are characteristic. We retrospectively analyzed CT studies of nine cases, all of which showed similar CT findings; a solitary, homogeneous, hypodense mass without bony destruction that extends from the maxillary sinus through the widened ostium into the choana.
Connective Tissue ; Maxillary Sinus ; Nasal Polyps ; Polyps* ; Retrospective Studies