Asbestos is a fibrous silicate that was widely used because of its heat resistance properties. Asbestos exposure affects workers involved in mining or processing asbestos or those involved in the use of asbestos in the shipbuilding, construction, and textile- and insulation-manufacturing industries. There are three commonly available types of asbestos; chrysotile (white asbestos), amosite (brown asbestos), and crocidolite (blue asbestos). All three have been associated with cancerous and non-cancerous lung disease. Asbestos-related diseases includes benign pleural effusion, pleural plaques, diffuse pleural thickening (a non-malignant disease affecting the lung lining), rounded atelectasis, asbestosis (a scarring of the lung tissue caused by asbestos), mesothelioma and lung cancer. Mesothelioma is a malignant pleural or peritoneal tumor that rarely occurs in patients who have not been exposed to asbestos. The latency period of most asbestos-related disease is 10 years or longer, asbestos-related disease remains an important public health issue. The clinical diagnosis of asbestos related diseases should be based on a detailed interview of the patient and occupational data on asbestos exposure, signs and symptoms, radiological and lung physiological findings and selected cytological, histological and other laboratory studies. Radiological imaging plays a pivotal role in the diagnosis and management of asbestos-related disease.
Asbestos ; Asbestos, Amosite ; Asbestos, Crocidolite ; Asbestos, Serpentine ; Asbestosis ; Cicatrix ; Compensation and Redress ; Hot Temperature ; Humans ; Latency Period (Psychology) ; Lung ; Lung Diseases ; Lung Neoplasms ; Mesothelioma ; Mining ; Pleural Effusion ; Public Health ; Pulmonary Atelectasis ; Silicates ; Workers' Compensation

The aim of this study was to compare the compositions and cytotoxicity of white ProRoot MTA (white mineral trioxide aggregate) and 3 kinds of Portland cements. The elements, simple oxides and phase compositions of white MTA (WMTA), gray Portland cement (GPC), white Portland cement (WPC) and fast setting cement (FSC) were measured by inductively coupled plasma atomic emission spectrometry (ICP-AES), X-ray fluorescence spectrometry (XRF) and X-ray diffractometry (XRD). Agar diffusion test was carried out to evaluate the cytotoxicity of WMTA and 3 kinds of Portland cements. The results showed that WMTA and WPC contained far less magnesium (Mg), iron (Fe), manganese (Mn), and zinc (Zn) than GPC and FSC. FSC contained far more aluminum oxide (Al2O3) than WMTA, GPC, and WPC. WMTA, GPC, WPC and FSC were composed of main phases, such as tricalcicium silicate (3CaO.SiO2), dicalcium silicate (2CaO.SiO2), tricalcium aluminate (3CaO.Al2O3), and tetracalcium aluminoferrite (4CaO.Al2O3.Fe2O3). The significance of the differences in cellular response between WMTA, GPC, WPC and FSC was statistically analyzed by Kruskal-Wallis Exact test with Bonferroni's correction. The result showed no statistically significant difference (p > 0.05). WMTA, GPC, WPC and FSC showed similar compositions. However there were notable differences in the content of minor elements, such as aluminum (Al), magnesium, iron, manganese, and zinc. These differences might influence the physical properties of cements.
Agar ; Aluminum ; Aluminum Oxide ; Calcium Compounds ; Diffusion ; Glutamates ; Guanine ; Humans ; Iron ; Magnesium ; Manganese ; Oxides ; Plasma ; Silicates ; Spectrometry, X-Ray Emission ; Spectrum Analysis ; Zinc ; Pemetrexed

Three cases of lipomas associated with heavy talc deposits are reported in local inhabitants near a fiber glass factory. Pathologic and mineralogical analysis by polarizing microscopy, scanning and transmission electron microscopy with energy dispersive X-ray analysis and X-ray diffraction of mass were done. Simultaneously, we performed an epidemiological survey and a mineralogical study of disposed fiber glass from waste site and ground water. All tumors consisted of mature fat tissue containing an abundant birefringent talc fibers and particles under polarized light. The concentrations of the fibers were 494.7, 6.7 and 50.7 million fibers per gram of dry tissue. The fibers were needlelike with rectangular fractured ends, up to 17 micrometer in length and 0.5 micrometer in diameter. EDX and X-ray diffraction analysis of the fibers showed that 71 to 100% of the fibers were magnesium silicate, talc. We also identified magnesium silicate fibers in the fiber glass from the waste site and in the ground water which were similar to talc fibers in lipomas,. We concluded that fibrous talc, a component of fiberglass waste, might be associated with the development of lipomas via unknown exposure route.
Environmental Exposure ; Foreign Bodies ; Glass ; Groundwater ; Lipoma* ; Magnesium ; Microscopy ; Microscopy, Electron, Transmission ; Nerve Fibers, Myelinated ; Silicates ; Talc* ; X-Ray Diffraction

Gastrointestinal melanosis is observed most frequently in the colon it also can develop in the ileum, duodenum and esophagus very rarely. Melanosis ilei was thought that causative materials such as aluminum, magnesium, silicate, titanium and other compounds entered the body through the ingestion of agents. We experienced a case of melanosis in the terminal ileum that a 65-year-old female patient ingested 10 g edible charcoal everyday for 3 years to address symptoms of chronic abdominal pain. In Korea, edible charcoal has been considered to be an effective folk remedy for patients with diarrhea or chronic abdominal pain. In our case, a follow up colonoscopy was performed 3.5 years after the termination of the ingestion of edible charcoal, at which point pigmentation was faded color intensity. In conclusion, it is thought that melanosis ilei is a rare disease by ingestion of causative materials and is discontinuous, local and reversible disease.
Abdominal Pain ; Aged ; Aluminum ; Capsule Endoscopy ; Charcoal ; Colon ; Colonoscopy ; Diarrhea ; Duodenum ; Eating ; Esophagus ; Female ; Follow-Up Studies ; Humans ; Ileum ; Korea ; Magnesium ; Medicine, Traditional ; Melanosis ; Microscopy, Electron ; Pigmentation ; Rare Diseases ; Silicates ; Titanium

This study was conducted to determine the relationship between exposure to glass fiber waste from an insulator factory and the development of cluster of lipomas among local residents in suburb Incheon, Korea. Authors surveyed 152 residents(71 males and 81 females) living near an insulator factory with a questionnaire and physical examination. Unused and disposed fiberglass from the waste site, along with ground water samples were examined under light and polarizing microscope and scanning electron microscope(SEM). Subcutaneous tumors excised from three of the residents were also examined under light and polarizing microscope, SEM with energy dispersive X-ray analysis(EDX), and transmission electron microscope(TEM). Analysis of elemental composition of the fibers and fiber concentration was done by with EDX under SEM and TEM after low temperature ashing. Twelve(7.9%) had subcutaneous tumors among the 152 residents. Tumors were surgically excised from 3 of them and they were all lipomas, consisting of mature fat tissue. These lipomas contained abundant birefringent fibers and particles under polarizing microscope. The concentrations of the fibers were 6.7, 71.8 and 499.2 million fibers per gram dry tissue, respectively. The birefringent fibers were composed of needle shaped particles with rectangular fractured ends up to 17 micrometer in length and 0.5 micrometer in diameter. EDX and x-ray diffraction analysis of the fibers showed that 71 to 100% of the fibers were magnesium silicate, talc. Magnesium silicate fibers were also found in the glass fiber sampled from the waste site. Glass fibers and magnesium silicate fibers were also identified in the ground water. Based on the fact that the magnesium silicate fibers found in the lipomas were similar in morphology and elemental composition to those found in the ground water and those from the waste site, these particles are likely to be introduced into the gastrointestinal tract through consumption of the contaminated ground water. It is suggested that fibrous magnesium silicate, talc, a component of fiberglass waste, may be associated with the development of lipomas.
Environmental Exposure ; Gastrointestinal Tract ; Glass* ; Groundwater ; Humans ; Incheon ; Korea ; Lipoma* ; Magnesium ; Male ; Needles ; Physical Examination ; Silicates ; Talc ; X-Ray Diffraction ; Surveys and Questionnaires

In order to develop tinted infiltration glass and its colorants, which can make the ceramic have good spectrum transmittance, color space, color stability and be suitable for clinical use, we selected the best prescription and confirm the ingredient and content of the colorants. Molten glass was prepared in Al2O3 crucible by heating the components to 1420 degrees C for 2 hours. The refractive index and thermal stability of the glass were investigated. The refractive index of the MIC infiltration glass was 1.5969(587.6 nm, nd). It was close to the index of aluminous matrix 1.759(546.07 nm, ne), which increased the spectrum transmittance of MIC. The thermal expansion coefficient of the glass was 7.565 microns/m/degree C, which was compatible with the thermal expansion coefficient of aluminous matrix(8.214 microns/m/degree C). This study proved that the tinted infiltration glass has good color stability, spectrum transmittance, and thermal expansion properties.
Aluminum Silicates ; Coloring Agents ; Crystallization ; Dental Porcelain ; Elasticity ; Glass ; Hardness

OBJECTIVETo evaluate the clinical prosthetic effect of IPS-Empress 2 pressahie ceramic crowns.

METHODS198 teeth of 70 patients were restored with IPS-Empress 2 pressahie ceramic crowns. The patients were asked to return in one week and every half year. The clinical prosthetic effect was evaluated.

RESULTSThrough follow-up of 3-38 months, the veneer porcelain crowns of 3 teeth were broken. 2 crowns fall off due to teeth fracture, gingivitis occurred in 2 teeth, pulpitis or periapical periodontitis occurred in 3 teeth. The shades of 3 crowns were darkening. The prosthetic effect of 185 teeth was satisfied. The rate of satisfaction was 93.4%.

CONCLUSIONIPS-Empress 2 pressable all-ceramic crown has the advantages of aesthetic effect, good hiocompatihility and simple fabrication. But its strength is not enough for posterior teeth and it can not cover the deep color of non-vital teeth and metal materials.

OBJECTIVETo explore the manufacture and clinical application of IPS-Empress casting ceramic restorations.

METHODSThe problems in manufacture and clinical operation of 215 casting ceramic restorations were analyzed.

RESULTSIn 215 casting ceramic restorations, 12 (5.58%) casting ceramic restorations were affected by clinical design or application, 15 (6.98%) casting ceramic restorations were affected by some manufacture problems, and 14 (6.51%) casting ceramic restorations were affected by clinical try-in. Through 2-3 years' follow-up, the achievement ratio of 215 IPS-Empress casting ceramic restorations was 94.88%, and 11 casting ceramic restorations were affected by some problems.

CONCLUSIONBeauty and simultaneous enamel wear are the characteristics of casting ceramic restorations. But because of its brittle, the indications should be strictly selected.

The phase constitution, microstructure and properties of a new type of machinable glass-ceramics containing fluorophlogopite-type (FPT) Ca-mica for used in restorative dentistry were investigated. According to the results of X-ray diffraction (XRD) and energy-dispersive spectrometry(EDS), its main crystalline phases were FPT Ca-mica and t-ZrO2, together with few KxCa(1-x)/2Mg2Si4O10F2, m-ZrO2. The flexible strength was 235 MPa, which was nearly two times larger than that of the present mica-based dental materials, and the highest fracture toughness was 2.17 MPa.m1/2. The microstructure had a great effect on properties, the glass-ceramics contained a large volume, and the fine crystals showed higher strength. The material possessed typical microstructure of machinable glass-ceramics and displayed excellent machinability during drilling test and CAD/CAM.
Aluminum Silicates ; Biomechanical Phenomena ; Ceramics ; Dental Materials ; Hardness ; Materials Testing

Sepiolite--an inexpensive, resourceful, fibrous yet inoffensive mineral--made DNA transformation rapid, simple and efficient but the mechanism for DNA transformation was still unclear. Through RNA competition test, we proposed the different transforming mechanisms from the previous report. Meanwhile, we optimized the transforming method and could transfer a colony stored at 4 degrees C for a month with plasmid through sepiolite fibers. The cells could be transformed well without competent cells preparation or incubation process. In sum, this was a novel potential transforming method, which could be explored further if the chemical method and electroporation could not be used.
DNA, Bacterial ; chemistry ; genetics ; Electroporation ; methods ; Magnesium Silicates ; chemistry ; Mineral Fibers ; Nanofibers ; chemistry ; Transformation, Bacterial